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venereum, coccidioidomycosis, anthrax, bartonella henselae, sporotrichosis,
plague, and tularemia.
Ulceroglandular syndromes.
Nodular lymphangitis.
HIV infection.
B-cell and plasma cell disorders
Non-Hodgkin lymphoma (NHL). NHLs are clonal proliferations, usually of
B-lymphocytes, at specic stages of maturation identied by surface markers.
Patients present with fever, weight loss, and night sweats, with abdominal
pain or fullness, or with palpable lymphadenopathy. They involve multiple
sites including non-lymphoid tissue, e.g., lung, stomach, intestine, and central nervous system. They are classied as high-grade disease that is rapidly
progressive but potentially curable, and low-grade disease for which curative
therapy is generally not available.
Hodgkin disease. This malignant disease of B-cells spreads to contiguous
lymph node beds, the spleen, liver, and bone marrow. There are age peaks
in the third and eighth decades. Symptoms include pruritus, painless lymph
node enlargement, abdominal pain, and occasionally periodic or continuous
fever (Pel–Epstein fever, Chapter 4, page 47) and cachexia. Frequently only a
single lymph node group is affected, most often in the neck (Fig. 5-4A). The
lymph nodes enlarge rapidly over 1–3 weeks or slowly over months and are
large, resilient or rubbery. Hepatomegaly and splenomegaly may be present.
Nephrotic syndrome may accompany or precede the diagnosis. A thorough
examination of all accessible nodes is required.
precipitates pain in the nodes so severe and predictable that patients abstain
from alcohol. Lymphadenopathy in non-Hodgkin lymphoma is usually generalized and rarely conned to the neck.
See page 81.
See also, Chapter 6, page 142.
See Chapter 6, page 142.
DDX: Rarely, drinking alcohol
Chronic lymphocytic leukemia (CLL). Lymph nodes and bone marrow are
inltrated by a clonal proliferation of mature lymphocytes (90% B-cell, 10%
FIG. 5-4Cervical Lymphadenopathy. A. Hodgkin disease. There is no specific pattern of node involvement.
The neck is frequently affected first, often unilaterally. The nodes are large, firm, discrete, nontender, and nonsuppurative.
B. Tuberculosis. One finds a matted mass of nontender lymph nodes. The nodes are firm and some have suppurated
forming draining sinuses.
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T-cell) with progressive cytopenias and impaired humoral and/or cellular
immunity.
nosis being about 70. Patients are often asymptomatic until relatively late in
the disease. They present with lymphadenopathy and progress to anemia,
neutropenia, and thrombocytopenia with recurrent infections. Death usually
results from infection or hemorrhage.
Waldenström macroglobulinemia. Proliferation and inltration of bone
marrow, spleen, and liver by proliferating plasmacytoid lymphocytes producing monoclonal IgM (macroglobulin). Elevated circulating IgM leads to
hemolytic anemia, immune thrombocytopenia, and increased blood viscosity. Symptoms are insidious onset of anorexia, malaise, weakness, nasal/
gingival bleeding, and exertional dyspnea. Signs include any combination of
pallor, petechiae, ecchymoses, retinal hemorrhages, lymphadenopathy, hepatosplenomegaly, edema, and heart failure.
Multiple myeloma. A clonal proliferation of plasma cells produces intact
immunoglobulins and/or light chains detectable in the serum and urine.
Humoral activation of osteoclasts leads to bone resorption without healing,
hypercalcemia, and pathologic fractures. Symptoms include bone and mus-
cle pain, backache, weakness, weight loss, and fatigue. There are no specic
signs. Bone pain may indicate a pathologic fracture.
Amyloidosis. Deposition of brillar amyloid proteins leads to organ enlarge-
ment and dysfunction. Several types are identied by the protein deposited.
AL amyloidosis results from immunoglobulin light chain deposition. AA
amyloidosis occurs in chronic inammatory diseases. The hereditary amyloidoses have specic brillar proteins.
be asymptomatic or cause organ dysfunction. Symptoms are weakness and
fatigue. Symptoms vary with the organ system involved: diarrhea, dysphagia, and weight loss (GI involvement); paresthesia (peripheral nerves); dyspnea, orthopnea, and pleural effusions (restrictive cardiomyopathy). Signs
also vary with the organs involved: macroglossia, eyelid plaques, hypertension, lymphadenopathy, hepatomegaly, splenomegaly, purpura, nephrotic
syndrome, edema, shoulder-pad sign, joint and muscle pain, neuropathy, and
uid in serous cavities.
clonal gammopathies, primary idiopathic amyloidosis; AA amyloidosis:
Chronic inammatory diseases (e.g., osteomyelitis, tuberculosis, leprosy),
familial Mediterranean fever, other familial periodic fevers.
CLL typically affects older adults, with the average age of diag-
Deposition of amyloid proteins can
CLINICAL OCCURRENCE: AL Amyloidosis: Multiple myeloma, mono-
Diseases and Syndromes of Specific Regional Lymph Nodes: Some infec-
tious, inammatory, or neoplastic lesions in the lymphatic drainage area
cause regional lymphadenopathy. Each cause of generalized lymphadenopathy can cause regional adenopathy. Here we list entities more specic to a
region.
Lymph node beds of the head and jaw
Suboccipital nodes. Location: Midway between the external occipital protuberance and the mastoid process (Fig. 5-1), near the great occipital nerve.
Drainage: Afferents from back of scalp and head; efferents to deep cervical
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nodes. Symptoms: Headache resulting from great occipital nerve impingement by large nodes.
worm, pediculosis capitis, seborrheic dermatitis, secondary syphilis, Kikuchi
disease, and metastatic cancer.
Postauricular nodes. Location: On mastoid process and at sternocleidomastoid insertion behind pinna (Fig. 5-1).
acoustic meatus, back of pinna, temporal scalp; efferents to superior cervical nodes.
causes are bacterial or herpetic infection of the acoustic meatus, rubella (not
rubeola), leishmaniasis.
Preauricular nodes.
Fig. 5-1).
vae, skin of temporal region, external acoustic meatus, and anterior pinna.
Clinical associations: Consider noninfectious causes like ulcerating basal cell
carcinoma and epithelioma. Infections associated with preauricular nodes are
erysipelas, ophthalmic herpes zoster, rubella, trachoma, ocular-glandular
syndromes, gonorrheal ophthalmia, tuberculosis, syphilis, sporotrichosis,
glanders, chancroid, epidemic keratoconjunctivitis, adenoidal-pharyngealconjunctival virus, Leptothrix infection, lymphogranuloma venereum, tularemia, cat-scratch fever, and Chagas disease.
Mandibular nodes. Location: Under the mandible (Fig. 5-1). Drainage: Afferents from tongue, submandibular gland, submental nodes, medial conjunctivae, mucosa of lips and mouth; efferents to supercial and deep jugular
nodes.
Submental nodes. Location: In midline under apex of the mandibular junction (Fig. 5-1). Drainage: Afferents from central lower lip, oor of mouth, tip
of tongue, skin of cheek; efferents to mandibular nodes, deep jugular nodes.
Symptoms: Mastoid tenderness simulating mastoiditis. Common
Drainage: Afferents from lateral eyelids and palpebral conjuncti-
Clinical associations: Commonly associated with ring-
Drainage: Afferents from external
Location: In front of the tragus of the external ear (see
Lymph node beds of the neck.
Jugular nodes. Location: Anterior border of the sternocleidomastoid, from
angle of mandible to clavicle (Fig. 5-1). Drainage: Afferents from tongue
except apex, tonsil, pinna, parotid gland; efferents to deep jugular nodes.
Clinical associations: Infection or neoplasm of the tonsils and oral cavity and
cancer, especially thyroid cancer are causes.
Posterior sternocleidomastoid nodes.
nocleidomastoid muscle (Fig. 5-1). Drainage: Afferents from the scalp and
neck, upper cervical nodes, axillary nodes, skin of arms and pectoral region,
surface of the thorax. Clinical associations: Malignancy, infections (e.g., EBV,
tuberculosis, toxoplasmosis, African trypanosomiasis). In trypanosomiasis,
these nodes are Winterbottom sign.
Scalene nodes. Although not palpable, they are easily biopsied. Location: Inferior deep cervical nodes lying deep in the supraclavicular fossa behind the
sternocleidomastoid. Drainage: Afferents from the thorax. Clinical associa-
tions: Intrathoracic granulomatous disease and neoplasms are serious causes.
Location: Posterior border of the ster-
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Important syndromes associated with cervical and supraclavicular
lymphadenopathy
Acute cervical lymphadenopathy—localized lymphadenitis. Infections of
the scalp, face, mouth, teeth, pharynx, or ear cause localized lymphadenitis
of the nodes draining the involved region. Included is chancre with regional
lymphadenitis. Cervical adenopathy is common in erythema
although the subcutaneous lesions are almost always limited to the legs.
In a toxic patient with severe tenderness, consider Lemierre syndrome
(Chapter 7, page236).
Subacute localized cervical lymphadenopathy: metastatic carcinoma. Asymptomatic head and neck cancers frequently present with cervical lymph
node metastases. The nodes are stony hard, nontender, and nonsuppurative.
Epidermoid carcinoma predominates. With anterior triangle involvement,
primary malignancies are in the upper aerodigestive tract, including the
maxillary sinus, oral cavity, tongue, tonsil, hypopharynx, and larynx. In the
submental region, metastases are from a primary neoplasms in the lower lip,
anterior tongue, or oor of the mouth. In the posterior triangle, the nasopharynx and scalp are common sites. Never surgically biopsy a solitary cervical lymph
node suspicious for metastatic cancer. Violation of the neck’s tissue planes may
preclude surgical cure. Always refer patients for direct exam of the aerodigestive tract by an experienced observer.
Sentinel node (Virchow node).
mary carcinoma in the upper abdomen enlarge a single lymph node, usually
in the left supraclavicular group, frequently behind the clavicular head of
the left sternocleidomastoid. It often escapes casual examination. Examine
behind the muscle head from in front, while the patient sits erect. The node
may be better appreciated with a Valsalva. Breast, lung, pelvic, and testicular
cancers can also spread to the supraclavicular fossa.
nodosum,
Metastasis via the thoracic duct from a pri-
Chronic localized cervical lymphadenopathy: tuberculosis (scrofula). This is
usually caused by M. bovis. Nodes are large, multiple, nontender, and classically matted; this is often difcult to determine by palpation (Fig. 5-4B). The
nodes frequently suppurate forming indolent sinus tracts. Extensive scarring
often results.
Kikuchi lymphadenitis. Cervical lymphadenopathy in a young woman is
characteristic. It is benign, but often confused with other entities.
Actinomycosis.
face, and cervical lymph nodes crossing tissue planes. The nodes are prone
to suppurate, forming sinuses with a bright-red hue. The pus contains sulfur
granules 1 to 2 mm in diameter.
Lymph node beds of the chest, axilla, and arms
Supraclavicular nodes. Location: Part of the inferior deep cervical chain behind the origin of the sternocleidomastoid muscle (Fig. 5-1). Drainage: Afferents from head, arm, chest wall, breast. Clinical associations: Granulomatous
diseases, lung and esophageal neoplasms; on the left, abdominal neoplasms.
Actinomyces bacteria from the oral ora infect the mouth,
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Axillary nodes. Location: Five groups lie on the medial humerus, the axillary
border of the scapula, and the lateral border of the pectoralis major (Fig. 5-3).
Drainage: Afferents from the arm, thoracic wall, and breast. DDX: In women,
enlarged axillary nodes on the chest wall must be distinguished from the axillary tail of the breast. Small mobile axillary nodes are common and normal.
Epitrochlear nodes. Location: In the groove between the biceps and triceps
~3 cm proximal to the medial humeral epicondyle.
ulnar aspect of forearm and hand, and entire little and ring ngers, the ulnar
half of the long nger. Clinical associations: The hands and arms are a common inoculation site of systemic infections, e.g., cat-scratch disease. Epitrochlear nodes are common in secondary syphilis (father-in-law sign).
Mediastinal nodes. Location: Chest x-ray shows mediastinal widening, anterior mediastinal mass, and/or an enlarged hilum. Clinical associations: Tuberculosis, coccidioidomycosis, histoplasmosis, anthrax, sarcoidosis, silicosis,
beryllium poisoning, erythema nodosum, Hodgkin disease, non-Hodgkin
lymphoma (lymphoblastic lymphoma), chronic lymphocytic leukemia, testicular cancer.
Abdominal and inguinal lymph node beds.
Abdominal nodes. Location: No clinical distinction made between
intraabdominal and retroperitoneal nodes. Large nodes may be palpated as
intraabdominal masses. Calcied nodes are seen radiographically. Clinical
associations: Primary lymphoma and metastases from testicular cancers
should be considered.
Inguinal nodes.
and vertically along the great saphenous vein. Drainage: Afferents of the horizontal group from the lower abdominal skin, retroperitoneum, penis, scrotum, vulva, vagina, perineum, buttocks, and lower anal canal; afferents of the
vertical group from the leg, penis, scrotum, and buttocks. Clinical associa-
tions: Palpable inguinal nodes are common without active disease. Testicular
tumors metastasize directly to paraaortic nodes not the inguinal nodes; scrotal cancer spreads to inguinal nodes.
Location: Lying horizontally along the inguinal ligament
Drainage: Afferents from
Genital lesion with satellite nodes. Clinical associations: Consider syphilis,
gonorrhea, chancroid, herpes simplex, lymphogranuloma venereum, tuberculosis, and cancer of penis.
THE HEMATOPOIETIC SYSTEM AND HEMOSTASIS
The hematopoietic and immune systems are interlinked through production
of B-cells, T-cells, and innate immune system cells (monocytes, macrophages,
neutrophils, eosinophils, and basophils). Practically, hematopoietic disorders affect red blood cells, neutrophils, and platelets either quantitatively, an
increase or decrease in the specic cell type, and/or qualitatively, a disorder
of function with, usually, a normal numbers of cells. Presentations vary with
the affected cell.
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Red Blood Cell (RBC, Erythrocyte) Disorders
Anemia. Anemia means a persistently low hemoglobin and hematocrit. It
results from decreased effective erythrocyte (red blood cell—RBC) production, blood loss, increased RBC destruction (hemolysis), and/or sequestration
of erythrocytes in an enlarged spleen. Decreased effective RBC
production
can be due to decreased erythropoietin (EPO) stimulus for RBC production
(e.g., chronic kidney disease), inability to respond appropriately to EPO
due to nutritional deciency (e.g., iron deciency) or
ineffective erythropoi-
esis resulting from defects in normoblast maturation. Patients present with
fatigue, dyspnea, decreased exercise tolerance, and weakness. Pallor is notable in the conjunctivae and palmar skin creases when the hemoglobin is <10
g/dL. On exam search for jaundice, lymphadenopathy, splenomegaly, hepatomegaly, and signs of hemorrhage. DDX: Unlike congestive heart failure,
dyspnea on exertion from anemia is not accompanied by orthopnea.
CLINICAL OCCURRENCE: Hypoproliferative: Iron deciency, anemia of
chronic disease, hypothyroidism, kidney failure, marrow damage (tumor
inltration, granulomatous disease, myelobrosis);
poiesis: Thalassemias, sickle cell disease, vitamin B
myelodysplastic syndrome; Hemolysis: Congenital erythrocyte disorders
Ineffective erythro-
and folate deciency,
12
(hereditary spherocytosis, hereditary elliptocytosis, glucose-6-phosphate
dehydrogenase deciency, pyruvate kinase deciency), autoimmune hemolytic anemias (warm-reacting, IgG; cold-reacting, IgM), paroxysmal nocturnal
hemoglobinuria (PNH), microangiopathic states (thrombotic thrombocytopenic purpura, hemolytic–uremic syndrome, malignant hypertension), infections, hemophagocytic syndromes, hypersplenism;
Sequestration: Massive
splenomegaly (chronic myelogenous leukemia—CML, portal hypertension);
Hemorrhage: Overt external bleeding, bleeding into body cavities and muscle,
or occult. Occult gastrointestinal hemorrhage is particularly common.
Iron deciency.
Iron is the key element in hemoglobin, myoglobin, and the
cytochromes necessary for energy production. The most common cause of
anemia worldwide, it results from decreased iron ingestion (rare since iron is
ubiquitous in the environment and all but the most restrictive diets), chronic
blood loss (menses, occult GI bleeding, phlebotomy), or rarely from iron
binding by phytates in the diet. Iron deciency in infants delays intellectual
development. Symptoms are weakness and lassitude often out of proportion
to the hemoglobin level.
Sickle cell disease.
Patients are homozygous for autosomal recessive hemo-
globin-S (HbS), which is unstable at low-oxygen tension. Aggregated HbS
produces RBC sickling. Sickled RBCs obstruct the microcirculation causing
ischemia and hemolysis. Persons of African ancestry are most commonly
affected. Compound heterozygotes with other hemoglobinopathies may
present with milder symptoms. Presentation is in childhood with painful crises associated with fever, malaise, headache, epistaxis, and pains in legs and
abdomen associated with hemolysis. Growth abnormalities include tower
skull, short trunk, thoracic kyphosis, and small stature. Additional signs are
abdominal and bone tenderness, pallor, yellow–green sclerae, cardiomegaly,
hepatomegaly, splenomegaly, and ulcers on shins.
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β-Thalassemia major. A homozygous β-chain gene mutation limits hemo-
globin synthesis leading to hemolysis and ineffective erythropoiesis. There
is bone marrow expansion, extramedullary hematopoiesis, and increased
hemoglobin-F production.
oid facies, prominent frontal bosses, hepatomegaly, splenomegaly, pallor, cardiac dilatation, and growth retardation.
β-Thalassemia minor. A heterozygous β-globulin gene mutation leads to
mild hypochromic, microcytic anemia. Patients are asymptomatic or have
mild fatigue and are often misdiagnosed with iron deciency because of the
hypochromic microcytic anemia. Iron overload occurs if iron is given inappropriately. Clue to diagnosis may be mild microcytic anemia with a highnormal or elevated RBC count.
Paroxysmal nocturnal hemoglobinuria (PNH). RBCs are susceptible to
complement mediated lysis due to acquired loss or a cell surface anchor protein. Symptoms include abdominal, retrosternal, or lumbar pain. There may
be chronic anemia, venous thrombosis, and hemoglobinuria at night. There is
an increased risk for acute leukemia.
The disease is evident in childhood with mongol-
Pernicious anemia and vitamin B
autoimmune gastritis decreases intrinsic factor production resulting in B
malabsorption. Other causes of B
absorption) are more common. Patients present with fatigue, glossitis, pro-
deciency. In pernicious anemia,
12
malabsorption (e.g., food-cobalamin mal-
12
12
prioception decits caused by posterior column disease, and/or dementia. A
high index of suspicion is required. Up to 5% of persons >75 years of age are
B
-decient. Other causes of B12 deciency include postgastrectomy, celiac
12
disease, small bowel bacterial overgrowth, intestinal parasites, distal ileum
resection, and dietary deciency.
Erythrocytosis—polycythemia. Increased RBC production results from
an abnormally proliferating clone (polycythemia vera) or is secondary
to hypoxemia, abnormal hemoglobins, renal tumors, or drugs (testosterone, erythropoietin).
Patients present with plethora and dyspnea. In
secondary polycythemia, there may be signs of advanced chronic lung
disease. Congestive heart failure with edema occurs with hematocrits >60%.
Hyperviscosity produces signs of organ dysfunction, stroke, and thrombosis. DDX: With polycythemia vera there is splenomegaly and increased
plasma and red blood cell volumes, usually with leukocytosis and
thrombocythemia.
Neutrophil Disorders
Neutropenia. Decreased neutrophil production (granulocytes, segmented
polymorphonuclear leukocytes-PMNs) results from aplastic anemia, a myeloproliferative syndrome, leukemia, infection, or drug toxicity. Hypersplenism
reduces the circulating PMNs. The patient is asymptomatic until the neu-
trophil count is <500 per mm
3
when infection with normal ora, especially
Staphylococcus aureus, Streptococcus pyogenes, and gram-negative GI ora are
greatly increased. Patients often initially present with fever and septicemia.
Febrile neutropenia accompanying cancer chemotherapy is a diagnostic and
therapeutic challenge.
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Leukocytosis. Increased neutrophil production is a normal response to infec-
tion and hemorrhage. An increase in bands is most consistent with infection.
Epinephrine and corticosteroids cause neutrophils adherent to vessel walls
(marginated pool) to demarginate increasing the neutrophil count by 50% to
100%. Increases in mature leukocyte counts are asymptomatic, even at levels
>200,000 per mm
3
. Diagnostic keys are symptoms and signs of underlying
disease. Persistent neutrophilia without evident cause suggests a myeloproliferative disorder such as polycythemia vera or CML. Many circulating
immature forms suggests CML.
Myeloproliferative Disorders and Acute Leukemia
Chronic myelogenous leukemia. An acquired balanced genetic transloca-
tion of the bcr gene on chromosome 22 and the abl gene on chromosome 9
leads to a functional fusion bcr–abl tyrosine kinase. Symptoms begin gradu-
ally with fatigue, malaise, loss of appetite, and abdominal fullness. There is
usually palpable splenomegaly which may become massive. With progression, anemia and thrombocytopenia occur. Progression terminates with transformation to a relatively refractory acute leukemia, the blast crisis.
Polycythemia vera (PV). Clonal proliferation of erythrocytes, neutrophils,
and platelets increases red cell mass and plasma volume leading to increased
blood volume, increased hematocrit, and decreased capillary blood ow
from increased blood viscosity. Patients present with fatigue, neurologic
symptoms, aquagenic pruritus, and thromboses. Spontaneous hepatic vein
thrombosis (Budd–Chiari syndrome) and portal or mesenteric vein thrombosis should trigger an evaluation for PV, even in the absence of elevated
hematocrit. Physical ndings are plethora and splenomegaly.
Essential thrombocytosis.
There is unregulated proliferation of platelets
leading to platelet counts >500,000 and often >1,000,000 per mm
are asymptomatic until presenting with bleeding or thrombosis, headache,
transient ischemic attacks, or hemorrhage.
Myelobrosis (myeloid metaplasia). Fibrosis obliterates the marrow space
leading to extramedullary hematopoiesis in the spleen and liver, and progressive pancytopenia. The cause is unknown. Patients complain of weak-
ness, increased fatigability, weight loss, pallor, and fullness in the left upper
quadrant. Splenomegaly and hepatomegaly are usually evident. Dependent
edema, bone pain, and fever may be present.
Acute leukemia. Several forms occur, all presenting with clonal proliferation
of immature myeloid or lymphoid precursors leading to marrow replacement,
neutropenia, and thrombocytopenia. The onset and progression are acute and
rapid. Symptoms may be fever, bleeding, or malaise. Prompt recognition and
treatment are required. Prevention of disseminated intravascular coagulation
associated with acute promyelocytic leukemia requires pretreatment with
all-trans retinoic acid.
Platelet Disorders
Thrombocytopenia. Decreased platelet production, increased platelet con-
sumption, immune-mediated platelet destruction, or hypersplenism are
3
. Patients
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the common causes. Patients present with defective hemostasis manifest as
bleeding gums, bruising, epistaxis, or bleeding following minor trauma or
surgical procedures. Signs include purpura from petechiae to large ecchymoses. Examine for splenomegaly, hepatomegaly, and lymphadenopathy.
Spontaneous intracranial hemorrhage is a signicant risk with platelet counts
<10,000 per mm
CLINICAL OCCURRENCE: Decreased production: Cytotoxic chemotherapy,
other drugs (e.g., heparin, thiazides, ethanol, quinine);
tion: Massive hemorrhage, hypertransfusion syndrome, thrombotic throm-
bocytopenic purpura, disseminated intravascular coagulation; Immune
destruction: Immune thrombocytopenic purpura, lymphomas, monoclonal
gammopathy of unknown signicance (MGUS), SLE, HIV infection, heparin-induced thrombocytopenia (HIT); Hypersplenism: Portal hypertension,
lymphoma.
3
.
Increased consump-
Immune thrombocytopenic purpura (ITP).
Antibodies to platelets lead
to their destruction in the spleen. Very low platelet counts persist despite
increased platelet production. ITP presents at any age and is especially com-
mon in women with other autoimmune diseases especially SLE. Monoclonal
gammopathies of unknown signicance (MGUS) may be associated. It is
asymptomatic, and the signs are those of purpura. Large platelets are seen
on peripheral smear.
Heparin-induced thrombocytopenia. Antibodies to platelet factor 4–hepa-
rin complex lead to rapid platelet agglutination either directly (HIT-I) or
secondary to immune mechanisms (HIT-II). Patients receiving heparin for
several days develop acute or worsening thrombosis, often of major arteries,
in association with thrombocytopenia. Persons previously exposed to heparin can have onset within hours of starting heparin. The symptoms and signs
vary with the sites of thrombosis and infarction.
Thrombocytosis. Increased platelet production occurs with myeloprolifera-
tive diseases, iron deciency, chronic inammatory disorders, and hemorrhage. This is usually asymptomatic until the platelet count is >750,000 per
3
mm
. Hemorrhage is the most common complication, although thrombosis
also occurs. See Essential Thrombocytosis, page 93.
Disorders of platelet function.
See Intradermal Hemorrhage, Chapter 6,
page 129.
Coagulation Disorders: Coagulation disorders are congenital or acquired.
Congenital abnormalities are usually a factor deciency or decreased factor
function. Acquired disorders may be factor deciencies or functional inhibition of coagulation. In either case, patients present with delayed bleeding
from sites of trauma, spontaneous hemorrhage into joints, and severe hemorrhage following surgical procedures.
Hypoprothrombinemia. Warfarin administration, vitamin K deciency, or
hepatic insufciency lead to deciencies of vitamin K-dependent coagulation
factors (II, VII, IX, X) and proteins S and C. Patients present with visceral
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bleeding including epistaxis, bleeding from gums, easy bruising, ecchymoses, hematuria, melena, and/or menorrhagia. Symptoms and signs of malabsorption may be present if the cause is malabsorption of fat-soluble vitamins
(A, D, E, and K).
Hemophilias: factor VIII deciency (hemophilia A and antibodies to factor VIII) and factor IX deciency (hemophilia B). The hemophilias are
clinically indistinguishable X-linked disorders with decreased synthesis of
physiologically active factor VIII or IX.
hood with spontaneous bleeding or excessive hemorrhage following dental
extractions and surgery. Hemarthroses lead to joint deformities and contractures. Antibodies to factor VIII are acquired in older adults, postpartum, with
drugs, and in SLE.
von Willebrand disease. von Willebrand disease (vWD) is a group of auto-
somal dominant defects in factor VIII von Willebrand factor production or
function. Patients present with signs of bruising and bleeding due to ineffec-
tive platelet adhesion. Aspirin use augments the hemostatic defect. The partial thromboplastin time (PTT) is prolonged. Many affected people are never
diagnosed.
Thrombophilia. Congenital or acquired disorders of coagulation and bri-
nolytic pathways lead to increased risk for thromboembolism. Patients
present with venous and, less commonly arterial, thromboembolism. Often
there is no identiable risk factor (e.g., trauma, surgery, immobility) other
than a family history of thromboembolic disease. Common causes are factor V Leiden, deciencies of antithrombin III, proteins C and S, prothrombin
gene mutations, and antiphospholipid syndrome. Arterial thromboembolism
suggests antiphospholipid syndrome, nonbacterial thrombotic endocarditis
(NBTE), or Trousseau syndrome.
Symptoms and signs begin in child-
Antiphospholipid syndrome. Antiphospholipid antibodies inappropri-
ately activate the clotting system leading to arterial and venous thrombosis.
Patients present with in-situ arterial thrombosis, venous thromboembolic disease, livedo reticularis, cardiac valve abnormalities, and/or frequent miscarriage. There is greatly increased risk of end organ damage and death. Though
frequently seen in association with SLE, primary antiphospholipid syndrome
rarely progresses to SLE.
THE ENDOCRINE SYSTEM
Endocrine disorders are common. Clinicians should think of endocrine disorders when patients present with systemic symptoms (fatigue, weakness,
anorexia, change in weight, and malaise) without fever or localizing symptoms and signs.
Diabetes and Hypoglycemia
Diabetes mellitus type-1. Immune destruction of β-cells in pancreatic islets
produces absolute insulin deciency resulting in hyperglycemia, osmotic
diuresis, impaired energy metabolism, and reliance on fatty acid oxidation
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