Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_4434_Библиотеки_им_академика_М_И_Перельмана.pdf
Paediatric Head andNeck
Pathology andSurgery
JeyasakthySaniasiaya andNorhazaMat Lazim
17
17.1 Introduction
Paediatric patients represent a special group of
patients who require different management and
therapeutic approaches. Numerous critical factors should be meticulously considered prior to
determining the perfect management options in
paediatric patients. Importantly, the human anatomy is signicantly different between the paediatric and the adult head and neck anatomy. This
alters surgical landmarks that are used during any
surgical procedures. In particular, the airway diseases pose life-threatening sequelae if it is poorly
managed. Other diseases and tumours of the paediatric patients also show some signicant variations. This can be in the aetiopathogenesis,
clinical presentation, required treatment and
complications. This should be meticulously
addressed by in-charge clinicians to ensure that
the best treatment outcomes can be achieved
(Table17.1).
J. Saniasiaya (*)
Department of Otorhinolaryngology, Faculty of
Medicine, Universiti Malaya, Kuala Lumpur,
Malaysia
e-mail: jeyasakthy@um.edu.my
N. Mat Lazim
Department of Otorhinolaryngology-Head and Neck
Surgery, School of Medical Sciences, Universiti Sains
Malaysia, Health Campus, Kubang Kerian,
Kelantan, Malaysia
e-mail: norhaza@usm.my
17.2 Common Tumours
inPaediatric Patients
17.2.1 Vascular Lesions
Vascular lesions which comprise vascular malformation and vascular neoplasms are commonly encountered in children, especially in the
newborns [1]. Despite benign in nature and
being mostly self-limiting, these vascular
lesions can be a part of syndromes, systemic
disorders or secondary complications. Vascular
anomalies have been classied according to the
International Society for the Study of Vascular
Anomalies (ISSVA), 2018, into the following
[2] (Table17.2).
17.2.2 Infantile Haemangioma
17.2.2.1 Introduction
Infantile haemangioma (IH) is considered to be
the most prevalent vascular neoplasm, which is
characterised by the presence of aberrant proliferation of endothelial cells as well as blood vessels. Other examples of vascular tumour include
congenital haemangioma, pyogenic granuloma,
tufted angioma and haemangioendothelioma.
17.2.2.2 Epidemiology
Approximately 5% of infants are affected by IH
[1, 3], of which IH amongst newborns has been
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022
N. Mat Lazim et al. (eds.), Head and Neck Surgery : Surgical Landmark and Dissection Guide,
https://doi.org/10.1007/978-981-19-3854-2_17
407
408
Table 17.1 Variation amid paediatric and adult head and
neck anatomy
Head and neck
anatomy Adult Paediatric
1. Neck and
larynx
2. Airway Narrowest
3. Bony Mature and
4. Skin and
surface area
5.
Subcutaneous
tissues
6. Neural and
vascular
structures
7. Morphology
of
neurovascular
structures
Table 17.2 Classication of vascular tumours
Categories of vascular
lesions Examples
1. Vascular tumours • Benign, borderline and
2. Simple
malformation
3. Combined
vascular
malformations
4. Anomalies of
major vessels
5. Vascular
malformations
associated with
other syndromes
Wide neck with
low larynx
airway is in the
glottic region
well-ossied
bones
Variation in
skin thickness
and surface area
Variation in
subcutaneous
tissue and skin
thickness
Variations in
neural and
vascular
structure
Neurovascular
structures are
well formed
malignant tumours
• Capillary malformations,
lymphatic malformations,
venous malformations and
arteriovenous stula
• Two or more vascular
malformations found in a
single lesion
• Congenital aneurysm
• Sturge-Weber syndrome,
Klippel-Trenaunay syndrome,
Proteus syndrome, CLOVES
syndrome, macrocephalycapillary malformation
Short neck with
high larynx
Narrowest airway
is subglottic
Underdeveloped
face and mandible
Thin skin with
greater body
surface area
Variable
subcutaneous fat
Supercial neural
and vascular
structures
Different colour,
consistency and
location of the
nerves
reported to be almost 1–3% [4]. Female preponderance has been noted over the years [5] with
female-to-male ratio of 1.4:1 to 3:1 [6, 7]. It is
noteworthy that gender disparity is higher
amongst paediatric patients with PHACE
syndrome (posterior fossa malformation, hae-
J. Saniasiaya and N. Mat Lazim
Fig. 17.1 Vascular malformation in a newborn with visible multiple patches of hyperpigmentation areas on the
neck and upper chest
mangiomas, cerebrovascular arterial anomalies,
cardiovascular anomalies and eye anomalies),
whereby the female predominance is reported
with a proportion of 9 females to 1 male [8].
IH has been found to be higher among preterm
infants, especially infants weighing under 1 kg
[6]. Interestingly, it has been reported that for
every 55g reduction of birth weight, the chance
of IH occurring amongst infants is 25% [9].
Besides low birth weight, other notable risk factors are advanced maternal age, multiple gestation, placenta previa, pre-eclampsia [6],
retroplacental haematoma, infarction and dilated
vascular communications [10] (Fig.17.1).
17.2.2.3 Pathogenesis
Despite the countless theories on pathogenesis of
IH, cellular origin from either intrinsic progenitor
cells or angioblasts of placental origin has been
the most plausible theory [11]. Apart from that,
intrinsic causes include angiogenic and vasculogenic components, whereas external causes
include hypoxia and growth disturbance [5].
17.2.2.4 Phases
IH has two evolutionary phases:
(a) Proliferative phase
(b) Involution phase
Proliferative phase begins upon early infancy,
which later progresses spontaneously into involution phase by 1year of age [12]. It is noteworthy
that intermediate phase occurs between proliferation and involution phase, which is normally dur-
17 Paediatric Head andNeck Pathology andSurgery
409
ing the near-late infancy period termed as
‘plateau’ phase. The ‘plateau’ or intermediate
phase represents a phase when there is equality
between individual proliferating cells and cells
going through involution and apoptosis [13]. The
involution phase takes several years.
17.2.2.4.1 Proliferative Phase
Early ndings include blanching or localised erythema. As IH enlarges, it obtains elevated, rubbery nature. Following the rapid growth period,
ulceration and pain followed by scarring may
occur. IH traditionally occurs prior to 4weeks of
age [13]. Yet, IH grows between 1 and 2months
of age [13].
17.2.2.4.2 Involution Phase
Involution phase occurs when the infant’s age is
from 6 to 12 months. Although this phase may
prolong longer, IH regresses before 4 years of life
[14, 15]. IH lesions usually atten from the centre
towards periphery. It is noteworthy that as IH
lesions resolve, myriad dermatological conditions
such as telangiectasia, brofatty tissue, excessive
skin, anetoderma as well as scar remain [16].
IH may appear as supercial or deep lesion.
Supercial lesion appears and involutes earlier as
compared to the deeper lesion.
vessel density of more than 5 vessels/cm2 along
with increased peak arterial Doppler shift of
more than 2 kHz has exhibited high sensitivity
and specicity of IH [17]. It is noteworthy that
ultrasonography can screen patients with multifocal IH to identify visceral involvement, notably
liver involvement [18].
Magnetic resonance imaging (MRI) is favoured
as it outlines the entire lesion as well as the surrounding anatomy with no risk of radiation.
Proliferating type of IH appears as well- demarcated
mass with high ow as well as intermediate in T1
and high intensity in T2 images [19]. Flow voids
may be noted in T2 images. Gadolinium administration will enhance the lesion with intense and
uniform enhancement, whilst non-enhancing areas
denote the presence of thrombosis or necrosis. On
contrast, increased signal is noted in T1 images
upon the involution phase as fat replaces the lesion
and contrast administration demonstrates low
enhancement.
As for computed tomography (CT), it is usually avoided due to risk of exposing the child to
ionising radiation. CT ndings are similar to
MRI as upon the proliferating phase of IH, CT
depicts well-delineated, enhancing lesion, whilst
the involution phase of IH demonstrates less avid
lesion.
17.2.2.5 Diagnosis
IH can be diagnosed clinically ensuing classical
appearance of ‘raspberry-red’ cutaneous lesions,
which increases in size along with the presence
of sharp margin. Biopsy or imaging is not
required for cutaneous haemangiomas.
Yet, presence of IH especially in difcult locations, requirement to identify the extension of
lesion, inconclusive diagnosis and associated
17.2.2.6 Treatment
Although IH is benign and has the potential to
involute spontaneously, it is prudent to identify
the necessity for intervention. Close observation
may be carried out in cases of uncomplicated
and stable IH.Yet, regular follow-ups are vital
as many uncomplicated IH can transform into
complicated stage during the early infancy
period [20].
complications warrant imaging. Ultrasonography
is the best initial imaging modality as it is cost
effective and rapid and the child does not require
1. Life-threatening complications such as airsedation. Ultrasonography of IH usually demonstrates well-delineated high-ow parenchymal
tumour with shunting occasionally.
2. Functional impairment such as failure to
Ultrasonography also enables IH to be differentiated from other deeper dermal or subcutaneous
lesions. Yet, its limitation is its inability to evalu-
3. To evaluate structural anomalies causing IH
4. To reduce potential long-term or permanent
ate deeper regions of the haemangioma. High
Indication of intervention includes [5]:
way obstruction or liver IH causing highoutput congestive heart failure
thrive, pain and bleeding
disgurement
410
J. Saniasiaya and N. Mat Lazim
Factors which inuence the choice of appropriate therapeutic modality include age, underlying comorbidity, growth phase, location of
IH, size of lesion, extension of lesion, being
single or multiple, severity, urgency of intervention, potential of psycho-emotional effects,
side effects of treatment as well as complications, parental preference and nally physicians’ experience.
17.2.2.7 Medical Therapy
Medical therapy includes both topical and systemic therapy. Topical agents are preferred for
smaller, localised and supercial lesions or in
patients with systemic drug contraindications.
Systemic route of therapy is prescribed in larger,
extensive, multiple lesions or in patients with risk
of functional decit or disgurement.
Popular medical therapies which are widely
used today include steroids, alpha-interferon [21,
22] and propranolol [23]. Besides that, novel
antiangiogenic agents are being used including
rapamycin [24], a macrolide with immunosuppressant and antiangiogenic potential, and bevacizumab [25].
17.2.2.8 Laser Therapy
Pulsed dye laser is a popular mode of therapeutic
choice for supercial IH. Yet, its limitation is
owing to its limited depth of penetration (<2mm).
Laser therapy can still be utilised in cases
whereby IH lesions are refractory to other treatments, in ulcerative IH or as a part of multimodal
therapy.
17.2.2.9 Surgical Therapy
Surgical indications include [26–28]:
1. Medical therapy contraindications
2. Failure of medical therapy
3. Focal, diffuse lesion in a favourable anatomical area
4. IH lesion which denitely needs surgical
resection
As a presurgical procedure, embolisation can
be carried out to facilitate removal as well as to
reduce preoperative bleeding. Embolisation is
preformed prior to surgery as a precaution to
reduce intraoperative blood loss as well as to
facilitate removal of the mass (Fig.17.2).
Fig. 17.2 Tongue haemangioma pre-resection and post-resection
17 Paediatric Head andNeck Pathology andSurgery
411
17.2.3 Dermoid Cyst
17.2.3.1 Introduction
Dermoid cyst (DC) is an uncommon cyst of
childhood, which may be either congenital or
acquired. DC is a benign cyst, which originates
from ectoderm and mesoderm. It comprises stratied squamous epithelium along dermal structures including hair follicles, smooth muscle,
sweat glands, sebaceous glands as well as adipose tissue [29]. Nearly 7% of all DC is found in
the head and neck region whereby it is predominately found in the periorbital, nasal, submental
and suprasternal region [30]. DC has no gender
predilection. Most DCs are evident before the
child is 5years old.
17.2.3.2 Classication ofAetiology
DC has been classied into three pathologic
types [31]:
(a) Acquired implantation
(b) Congenital teratoma
(c) Congenital inclusion
The acquired type of DC occurs after traumatically implanted portion of skin occurs in deeper
parts of the skin. Congenital teratoma forms from
all three types of embryonic germinal epithelium
as well as elements of epithelium, bone and cartilage. Congenital inclusion DC occurs resulting
from embryonic fusion and contains dermal as
well as epidermal structures. DC is the congenital
inclusion type.
17.2.3.3 Clinical Presentation
Head and neck DC appears as a traditionally
asymptomatic cystic mass. The cystic mass may
enlarge or become inamed following infection
or trauma. Additionally, it is worth noting that if
the DC is ruptured, the contact between the cyst
content and surrounding structures may cause
inammatory reaction. This most commonly
occurs amongst the periorbital DC.
DC is traditionally associated with a midline or
near-midline lesion with the exception of orbital
DC.Yet, lateral dermoid cyst has been postulated to
be midline cyst, which has migrated laterally [32].
17.2.3.4 Imaging
Ultrasound is able to differentiate with other
masses such as lymph node and schwannoma.
MRI aids to diagnose especially intracranial DC
and for surgical planning as well as to assess
treatment outcome. In case of a nasal DC with
intracranial connection, three-dimensional reconstructed MRI is helpful. MRI reveals hyperintensity in T2-weighted images [33].
17.2.3.5 Treatment
17.2.3.5.1 Surgery
Excision of DC is the gold standard treatment
[34]. The range of age can vary from 1month to
63years [35]. It is prudent when performing the
excision as the content of DC may lead to foreignbody reactions and other complications when it
comes in contact with the surrounding structures.
The recent advent of instrumentations has aided
surgical outcome as well as morbidity, especially
minimally invasive endoscopic procedures.
17.3 Thyroglossal Duct Cyst
17.3.1 Introduction
Thyroglossal duct cyst (TGDC) is the most prevalent congenital mass amongst paediatric
patients. Traditionally, TGDC is encountered as a
cystic lesion in the midline of the neck of children. The TGDS forms from the epithelial remnant of thyroglossal tract [36]. TGDC is present
in 7% of population [37, 38]. No gender predominance has been reported. It is worth noting that,
albeit a benign lesion, the risk of malignant transformation has been reported to be approximately
1% [39].
17.3.2 Embryology
Thyroglossal duct is an epithelial connection between
thyroid gland and foramen caecum. The thyroglossal
duct tract commonly disappears at the end of eighth
week. However, the tract can remain as a brous cord
or epithelial tube [40]. TGDC does not have an exter-
412
nal orice since the course of the tract does not extend
to the neck surface [41].
17.3.3 Clinical Presentation
Patients traditionally present with cystic mass in
the midline, which moves upon tongue protrusion. Mass is oftentimes asymptomatic although
slight tenderness may occasionally be present.
Mass may enlarge suddenly following trauma or
following upper respiratory tract infection. Apart
from that, dysphagia, odynophagia, choking or
foreign-body sensation may ensue TGDC.Albeit
uncommon, TGDC causing sudden death from
respiratory distress has been reported [42].
Most of the TGDCs are located close to the
hyoid bone. Infrahyoid is the commonest location (85%), followed by suprahyoid (8%) and
base of tongue (1–2%), and nally in 5% of children, the cyst was detected low in neck [43, 44].
It is noteworthy that TGDCs are located 2cm
from midline although it can be found at a more
lateral position. TGDC is also associated with
ectopic thyroid. Ectopic thyroid tissue can be
found within the walls of TGDS [45].
Interestingly, ectopic thyroid tissue was found in
up to 65% of TGDC when examined histologically [46]. Parallel to that, nearly 1–2% of
patients suspected with TGDC turned out to be
having ectopic thyroid gland [47].
17.3.4 Diagnosis
17.3.4.1 Blood Investigation
Thyroid function test needs to be carried out in
cases suspected of ectopic thyroid or clinically
suspicious for hyperthyroid or hypothyroid.
17.3.4.2 Fine Needle Aspiration
Cytology (FNAC)
FNAC enables TGDC to be determined histologically as well as to exclude other neck lesions.
J. Saniasiaya and N. Mat Lazim
Fig. 17.3 CT neck revealing enhancing cystic lesion
anterior to neck
17.3.4.4 Imaging
Ultrasonography is able to reveal the cystic
nature of TGDC so as to look for any abnormality
of thyroid gland. However, the relationship
between the cyst and surrounding structures’
notable hyoid bone is difcult to be established.
Ultrasonography features include well-dened,
thin-walled, hypoechoic or anechoic mass.
Contrasted CT is the ideal tool. CT imaging is
able to delineate the cyst as well as to outline the
relation between the cyst and surrounding structures. TGDC normally appears homogenous with
thin enhancing rim, whilst extra enhancement
indicates infection [48]. MRI demonstrates
hyperintensity on T2-weighted images. It enables
delineation between the cyst as well as structures
in the vicinity (Fig.17.3).
17.3.5 Treatment
17.3.4.3 Histology
TGDCs are lined by stratied squamous epithelium or pseudostratied ciliated columnar epithelium [36].
17.3.5.1 Surgery
Surgery remains the gold standard treatment using
Sistrunk method, which comprises cyst excision in
addition to excision of the proximal part of the
17 Paediatric Head andNeck Pathology andSurgery
413
tract and body of hyoid bone. Recurrence rate following Sistrunk procedure is 3% [49]. Simple
excision of the cyst has demonstrated recurrence
in more than 50% of cases. It is noteworthy that
suture-guided transhyoid pharyngotomy, a modication of Sistrunk operation, has been postulated
to enable better visibility of the normal structures
as well as to provide the route of entry to tissue
between hyoid bone and foramen caecum [50].
17.3.5.2 Sclerotherapy
Alternative approach especially in children who
are not t for surgery is percutaneous ethanol injection, although its effectiveness is still debatable.
17.4 Rhabdomyosarcoma
17.4.1 Introduction
Rhabdomyosarcoma is a malignant neoplasm
which entails primitive mesenchymal tissue
origin that expresses myogenic differentiation.
Soft- tissue sarcoma is found in approximately
60% of the paediatric age group [51, 52] to be
RMS, whilst the numbers are lower in adults
with approximately 2–5% [53]. Following neuroblastoma and Wilms’ tumour, RMS is the most
prevalent extracranial solid neoplasm amongst
paediatric patients [54, 55].
17.4.2 Epidemiology andAetiology
RMS expresses dual-age distribution as the rst
peak presents in the rst decade and the second
during the teenage group [56]. Age distribution
for RMS has been reported to be 1% for children
under 1year of age, 35% amongst children within
1–4 years of age, 25% in children within
5–9 years of age, 20% in children from 10 to
14years of age and 13% amongst children above
15years of age [57]. Only a slight male predilection has been reported [56, 58].
Interestingly, RMS is found to be higher in
children of mothers with a history of breast
tumour, though its pathogenesis has not been
conrmed. Other notable risk factors include
genetic factor ensuing RMS correlation with
Recklinghausen disease [59], Li-Fraumeni syndrome [60], Costello syndrome, Noonan syndrome [61], Beckwith- Wiedemann [62] as well
as mothers’ history of narcotic abuse [63].
17.4.3 General Characteristics
Head and neck RMS accounts for approximately
35% [51, 52] and can be classied into three subtypes [64]:
(a) Parameningeal
(b) Orbital
(c) Non-orbital non-parameningeal
Parameningeal RMS includes tumours located
in the nasal cavity, nasopharynx, paranasal sinus,
middle ear and skull base and comprises 25% of
RMS [65]. This group of tumours are oftentimes
difcult to achieve complete resection. Upon
early stage, patients remain asymptomatic and
have subtle presentation such as haemo-purulent
discharge or blockage of aural and sino-nasal
cavity, or dysphagia [66] which oftentimes mimics chronic mucosal inammation leading to
delay in diagnosis.
Orbital RMS comprises 9% of RMS [65].
This group of RMS carries good prognosis ensuing its early presentation, which includes exophthalmos, strabismus and periorbital ecchymosis.
Other subgroups of RMS are located within the
soft tissue of the neck, salivary glands, oral cavity, laryngopharyngeal region as well as thyroid
glands. Due to its rapid proliferating nature, vital
structures in the vicinity as well as lymph node
involvement have been reported. It is noteworthy
that metastasis to distant organs is more likely in
this group of tumours rather than lymph node
involvement. Involvement of distant organs such
as lungs, bones, bone marrow, central nervous
system, liver and retroperitoneal region has been
reported [67].
414
J. Saniasiaya and N. Mat Lazim
17.4.4 Histology
RMS comprises small round blue cell tumours
that encompass small cells along large, round,
hyperchromatic nucleus, which stains dark blue
by haematoxylin and eosin.
Histologically, RMS can be further subdivided
into [68, 69]:
(a) Embryonal
(b) Alveolar
(c) Pleomorphic or undifferentiated
Embryonal which comprises 60% of RMS is
reported to be the most prevalent type within the
head and neck [64] which carries best prognosis.
Alveolar type of RMS, comprises 20% of RMS
and is localized within the extremities, trunk,
perineum and paranasal sinus, whereas the pleomorphic RMS is normally located in the extremities and oftentimes involves adults. Histological
subtypes are prudent so as to decide the outcome
of treatment. Other additional histochemical testing includes desmin, myoglobin, actin and vimentin (Fig.17.4).
17.4.5 Diagnosis
RMS is diagnosed ensuing meticulous history taking, physical examination, imaging, histological,
laboratory as well as occasionally molecular test.
Presentation of mass, especially when it is
xed and hard in consistency which has presented
for longer than several weeks, requires through
investigation as malignancy should be ruled out.
Examination should include general inspection,
palpation, cranial nerve examination, lymph node
examination as well as nasoendoscopic, otoscopic
as well as 70° rigid endoscopy. Additionally, general systemic examination including lung auscultation, abdomen, extremities and genitalia
examination should be carried out to detect distant metastasis.
Imaging is an important diagnostic modality.
MRI is favoured as it depicts tumour size, its
precise location, extension, presence of metastasis to lymph node and distant involvement.
Additionally, presence of residual mass following treatment or recurrence can be visualised
via MRI.It is noteworthy that, however, MRI
requires the child to be sedated without risk of
radiation.
Other imaging modalities include computed
tomography (CT), ultrasound and positron emission tomography (PET). CT enables evaluation of
bone inltration and skull base inltration. It is
noteworthy that PET scan is an excellent modality
to diagnose residual tumours [70]. Yet, PET/CT
has been recently deemed superior in detecting
bone metastasis as well as lymph node metastasis
[71, 72], which is crucial as 15% of patients were
reported to have distant metastasis upon presentation (Fig.17.5).
Fig. 17.4 HPE revealing small round blue cells in a child
with temporal bone embryonal rhabdomyosarcoma
Fig. 17.5 RMS of left temporal bone in a 5-year-old
revealing extensive erosion of the left mastoid cortex,
ossicles and facial canal
17 Paediatric Head andNeck Pathology andSurgery
Table 17.3 Disease staging dependant on tumour site, size and presence or absence of metastasis
Stage Sites T Size N M
I Orbit, head and neck (except parameningeal) T1 or T2 a or b N0 or N1 or Nx M0
II Parameningeal T1 or T2 a N0 or Nx M0
III Parameningeal T1 or T2 a N1 M0
b N0 or N1 or Nx M0
IV All T1 or T2 a or b N0 or N1 M1
415
17.4.5.1 Biopsy
Biopsy is required to obtain the denitive diagnosis. Sampling can be obtained via open or needle
biopsy. Fine needle aspiration as well as tru-cut
biopsy can be carried out for inaccessible regions
under imaging guidance and can be a less invasive mode of obtaining diagnosis.
17.4.6 Staging
Staging is according to the size and presence of metastasis (Table17.3). It is noteworthy that, upon presentation, most children present at stage III of disease.
3-Year failure-free survival rate is 86% for stage I, 80%
for stage II, 68% for stage III and 25% for stage IV.
Tumour
• T1: conned to anatomic site of location
• T2: extension and/or xation to the surrounding tissues
Size
• a: <5cm in diameter
• b: >5cm in diameter
Regional Nodes
• N0: regional nodes not clinically involved
• N1: regional nodes clinically involved by
neoplasm
• Nx: clinical status of regional nodes unknown
Metastases
• M0: no distant metastases
• M1: metastases present
oncology team, otorhinolaryngologists, reconstructive surgeons, neurosurgeons, nutritionists,
psychologists, physiotherapists and counsellors.
The treatment focuses to achieve local control
and prevent metastasis whilst maintaining functional and cosmetic appearance. Myriad protocols have been developed, which have evolved
throughout the years. Treatment mainly involves
chemotherapy with or without surgery as well as
radiotherapy.
17.4.7.1 Chemotherapy
Chemotherapy has been regarded as the main
modality in treatment despite surgical resection
following the presence of micrometastasis upon
diagnosis. Utilisation of combined chemotherapeutic agents has revealed success by increasing the overall survival rate [65, 73]. Yet,
combination of drugs as well as its dosage
depends on risk group, histology type, surgical
resection, age as well as general condition of
patient [74].
Gold standard multi-agent chemotherapy has
been vincristine, actinomycin D,
cyclophosphamide (VAC) or ifosfamide (VAI). It
is noteworthy that, in low-risk group, VAC has
shown a success rate of 90%. In intermediate-risk
group, either VAC or VAI can be utilised with
survival rate reaching 70% [75]. A more intensive
treatment is deemed necessary in children with
metastasis as it has poor prognosis. Children
within group IV category are recommended to
undergo aggressive chemotherapy followed by
autologous myogenic stem cell transplantation
[76, 77].
17.4.7 Treatment
Multidisciplinary team should be involved in
managing RMS in children including paediatric
17.4.7.2 Radiation Therapy
Radiation is a crucial part of therapy besides
amongst children within the low-risk tumour category. It is noteworthy that radiation therapy is a
favoured modality as only 15% of RMS patients
416
J. Saniasiaya and N. Mat Lazim
(group I) achieve total recuperation. Radiation
therapy is administered in RMS children, especially with residual disease. The total radiation dosage is individualised according to protocol regime.
Delay in radiation therapy leads to local
tumour relapse. The recommended dose of radiation is between 36 and 50.4Gy. Lesser dosage is
given in patients in group II following microscopically incomplete surgical resection. In case
of residual or unresected tumour, greater radiation dosage is required. The challenge in radiation therapy is owing to the numerous vital
structures which are located in the vicinity, which
may lead to delayed radiation adverse effects.
17.4.7.3 Surgical Therapy
Many authors advocate surgery to be the primary
mode of treatment. 10% of new identied cases
are surgically resectable [65, 73]. Additionally,
non-parameningeal RMS enables complete surgical resection, notably ear, zygoma, soft palate,
tongue as well as supraglottis, whereas the parameningeal RMS poses a challenge for complete
tumour resection [64].
Complete surgical resection with negative
margin is ideal as survival rate is increased and
avoids radiation therapy [78, 79]. Having said
that, if unacceptable morbidity is postulated, surgical resection should be avoided.
17.5 Juvenile Nasopharyngeal
Angiobroma
17.5.1 Introduction
Juvenile nasopharyngeal angiobroma (JNA) is a
rare, aggressive non-cancerous, vascular tumour
which occurs predominately amongst adolescent
boys [82]. JNA is deemed aggressive owing to its
tendency to spread locally and its possibility to
extend into the skull base and intracranial region.
17.5.2 Epidemiology
JNA is reported in 0.5% of all head and neck
tumours whilst affecting 1in every 150,000 individuals. It affects adolescent males aged between
11 and 25 years [83], although average age is
15 years in most studies [82]. Presentation in
older patients, notably beyond 25 years, is
uncommon. JNA has been reported to be more
common in the East, especially Indian continent,
as compared to the West [84]. As this tumour
occurs exclusively amongst males, occurrence in
females requires genetic testing.
17.5.3 Aetiology
17.4.8 Prognosis
Outcome of treatment depends largely on the
anatomic site of involvement, child’s age, stage
as well as histology type. Poor prognostic factors
include older age child, presence of metastasis,
large tumour size, alveolar type of RMS and
parameningeal RMS [80].
17.4.9 Recurrence
Local or metastatic recurrence is demonstrated in
nearly one-third of children albeit after aggressive treatment. Patients who underwent surgery
have been reported to demonstrate better outcome, notably those who had complete surgical
resection [81].
JNA originates predominately at the superior lip
of the sphenopalatine foramen, formed by pterygoid process of the sphenoid bone and sphenoidal process of the palatine bone. Apart from
sphenopalatine foramen, other possible sites of
origin include pterygopalatine fossa, base of
sphenoid bone, sphenoid sinus, paranasal sinus
region and lacrimal sac. Tumour spreads submucosally into the adjacent structures.
17.5.4 Pathogenesis
Close relation between these tumours as well as
androgen receptor expression postulates that this
tumour is androgen dependant, hence its predominance amongst males [83, 85]. Apart from
androgen theory, other postulated theories
include [86] undifferentiated epithelioid nest