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_1499_Библиотеки_им_академика_М_И_Перельмана.pdf
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
Outcome
Data evolving in the literature:
Localized GIST: disease-specific 1-year survival 80–90%, 5-year survival approximately 50% after complete surgical
resection.
Metastatic GIST: median survival about 20 months, but 80% of patients show initial benefit from imatinib.
Follow-Up
Overall clinical follow-up not yet clearly defined:
imaging studies: CT, PET in regular intervals.
continued endoscopy (colonoscopy, EGD) in at least 6–12 months intervals.
depending on location: endorectal ultrasound.
Cross-Reference
Computed tomography (CT scan) (Ch. 2)
Positron emission tomography (PET/PET-CT) (Ch. 2)
Imatinib (Gleevec) (Ch. 6)
CARCINOID TUMORS (235.2)
Overview
Carcinoids are of neuroendocrine origin and represent the most frequent endocrine tumor of the GI tract but comprise only <
1% of GI tumors overall: biologically/morphologically heterogeneous, size-dependent potential to metastasize (liver, lung,
bone, etc), frequently multicentric.
Modern nomenclature: carcinoids are classified as neuroendocrine tumors. Historically: labeled as APUDomas based on
neuroectodermal cell origin with common biochemical steps of amine precursor (5-hydrotryptophan) uptake and
decarboxylation to produce several biologically active amines (serotonin, bradykinins, histamine, vasoactive intestinal peptide
[VIP], ACTH, prostaglandins, substance P, etc). Circulating serotonin and other active peptides metabolized during first-pass
effect in the liver (eg, serotonin
urinary metabolite 5-hydroxyindolacetic acid [5-HIAA]): therefore, carcinoid syndrome
generally only manifests once liver or other systemic metastases are present.
Tumor characteristics vary depending on location. Definition of malignancy is based on invasion or presence of metastases,
not on histologic picture. Growth pattern: slow progression with development of metastases after 7–14 years; metastatic
potential dependent on depth of invasion and size:
< 1 cm: low probability.
1–2 cm: gray zone: uncertain behavior (< 3% metastases).
> 2 cm: high probability of metastases (30–60%).
Epidemiology
Prevalence in US: 50,000 cases; incidence in US: estimated at 1.5–5.5 new cases per 100,000 people. Slight female
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
preponderance. Peak age: 50–70 years. Constitutes 12–35% of all small bowel tumors, 15–45% of all small bowel
malignancies.
Distribution pattern of GI carcinoids (caveat: difference between clinical vs autopsy series!): small intestine 40–45%
(particularly ileum >> jejunum >> duodenum), rectum 12–20%, appendix 15–20%, colon 7–10%, stomach 5–10%.
Historical data: appendix 40% > rectum 12–15% > small bowel 10–14%.
Multicentricity: ileal 25–30%, colon 3–5%.
Symptoms
Early (most frequently): asymptomatic incidental discovery on colonoscopy or surgery for other abdominal conditions.
Intermediate size: intermittent vague abdominal pain (partial/intermittent obstruction, postprandial intestinal angina).
Metastatic disease:
– Carcinoid syndrome (in < 10% of midgut carcinoids): flushing (80–85%), GI hypermotility with diarrhea (~70%),
carcinoid heart disease (30–40%, right heart disease), bronchial constriction/wheezing (15–20%), myopathy (5–10%),
pellagra-like skin pathology (5%), weight loss, arthralgia, peptic ulcers.
– Peritumoral fibrosis:
intestinal obstruction 50–75%
Associated symptoms: from associated tumors in multiple endocrine neoplasia type I (MEN-I) syndrome (foregut carcinoids).
Differential Diagnosis
IBS or spastic colon.
Noncarcinoid GI malignancies: large intestine cancer, small intestine cancer (proximal > distal), stomach/pancreas, OB/GYN,
carcinomatosis, GIST, lymphoma, melanoma (melanotic, amelanotic), mesothelioma, etc.
Benign extramucosal tumors: lipoma, leiomyoma, etc.
Pathology
MACROSCOPIC
Yellow-gray to pink-tan submucosal nodule/thickening up to sessile/pedunculated polyp; with increasing size
ulcerated, annular, obstructive, peritoneal/mesenteric fibrosis.
Tumor extent at presentation: locally advanced/metastatic spread in 3–5% of rectal carcinoids, 13–38% of midgut
carcinoids
liver, peritoneal, omentum, lung, bone, lymph node involvement (~80%), simultaneous satellite lesions >
25–30%.
Secondary pathology: carcinoid heart disease (plaque-like fibrous endocardial and valvular thickening in the right
heart).
Associated neoplasms: colonic malignancy in 2–5% of colonic and in 30–60% of ileal carcinoids; other associated
malignancies: lymphoma, breast.
MICROSCOPIC
Submucosal nests of round/polygonal cells with prominent nucleoli and eosinophilic cytoplasmic granules.
Five histologic patterns: insular, trabecular, glandular, undifferentiated, mixed. Limited value of traditional
morphologic criteria to assess malignant potential.
IMMUNOHISTOCHEMISTRY
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
Chromogranin A (CgA) and synaptophysin positive; in addition:
Foregut carcinoids: argentaffin-negative, argyrophil-positive, produce 5-hydrotryptophan.
Midgut carcinoids (duodenum to midtransverse colon): argentaffin-positive, argyrophil-positive, frequently
multicentric, produce several vasoactive compounds
carcinoid syndrome.
Hindgut carcinoids (distal transverse colon to rectum): rarely argentaffin- or argyrophil-positive, typically solitary;
carcinoid syndrome < 5% of colonic carcinoids, almost never for rectal carcinoid (do not produce serotonin).
Evaluation
REQUIRED MINIMAL STANDARD
Suggestive symptoms screening tests:
Chromogranin A (plasma): positive 75–90% of foregut, midgut, and hindgut carcinoids.
5-HIAA levels (random urine sample or 24-hour urine): positive 70–85% of foregut and midgut carcinoids, but
negative in hindgut carcinoids.
Positive screening test, positive incidental biopsy, suspicious incidental imaging finding:
Endoscopy: small bowel: capsule endoscopy; colon: colonoscopy; rectum: colonoscopy plus endorectal ultrasound.
Imaging:
– CT/MRI: liver and lymph node metastases (
CT-guided biopsy), "spoke wheel" desmoplastic mesenteric
masses.
– Octreotide scintigraphic scan (
111
In-labeled octreotide): 80–90% sensitivity.
Evidence of metastatic disease: echocardiogram.
ADDITIONAL TESTS (OPTIONAL)
PET, PET-CT: uncertain value because of slow progression and low metabolic rate of tumor.
Blood work: anemia, liver function (albumin, PTT, PT), kidney function.
Classification
Based on site of origin: foregut, midgut, hindgut.
Based on specific location: small bowel, appendix, colon, rectum.
Based on stage: localized, locally advanced (size, infiltration of other structures), loco-regional metastatic, distant
metastatic.
Based on secretory activity: functional vs nonfunctional.
Nonoperative Treatment
For palliation (patient not operable or not curable extent of tumor):
Carcinoid syndrome (flushing, diarrhea, wheezing): somatostatin-analogues (octreotide).
Tumor control/reduction: no benefit from conventional chemotherapy or radiation intra-arterial 5-FU?
Streptozotocin? Systemic fluorodeoxyuridine (FUDR) + doxorubicin? Interferon? Radioactively labeled somatostatin
analogues.
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
Preoperatively in preparation for surgery: octreotide prevent carcinoid crisis.
Supportive measures: eg, for diarrhea—loperamide, cholestyramine, etc.
Operative Treatment
INDICATION
Curative intent: standard oncologic resection = treatment of choice for any operable patient and amenable tumor
extent
avert local complications, decrease hormone secretion, limit secondary pathology.
Palliative intent: debulking, cytoreduction, wedge resection obviate mechanical bowel obstruction, decrease of
endocrine symptomatology.
OPERATIVE APPROACH
Appendiceal carcinoid:
– < 1 cm and not at base (70–80%): appendectomy.
– 1–2 cm or mesoappendiceal extension or subserosal lymphatic invasion (
0–3% metastatic): right hemicolectomy.
– > 2 cm, appendiceal base, mucin production (30% metastatic): right hemicolectomy.
Small bowel and colon: standard oncologic resection.
Rectum:
– < 2 cm, no invasion of muscularis mucosa: transanal excision.
– > 2 cm or invasion of muscularis mucosa: oncologic resection.
Hepatic metastases: liver resection (formal vs metastasectomies), radiofrequency ablation, chemoembolization; occasionally
orthotopic liver transplantation.
Prophylactic cholecystectomy (in case of a palliative resection) to mitigate biliary toxicity of octreotide treatment.
Outcome
Five-year survival rates: 65–75% overall survival based on location and tumor extent:
Small bowel carcinoid: overall 70–80%, local disease 90–95%, lymph node involvement 75–85%, distant metastases
40–50%.
Appendiceal carcinoid: overall 70–80%, local disease 90–95%, lymph node involvement 75–85%, distant metastases
35–45%.
Rectal carcinoid: overall 85–90%, local disease 90–95%, lymph node involvement 45–55%, distant metastases 5–
15%.
Colon carcinoid: local disease 45–95%, lymph node involvement 25–75%, distant metastases 10–30%.
Follow-Up
Hepatic carcinoid metastases: resection, chemotherapeutic embolization, cryotherapy, hepatic arterial infusion
chemotherapy.
Octreotide scan and blood tests at regular intervals.
Cytoreductive surgeries as needed.
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
Cross-Reference
Computed tomography (CT scan) (Ch. 2)
Positron emission tomography (PET/PET-CT) (Ch. 2)
Nuclear scintigraphy (Ch. 2)
Colorectal cancer—liver metastases (197.7) (Ch. 4)
Chemotherapy protocols—curative intent (colorectal cancer) (Ch. 6)
Chemotherapy—metastatic colorectal cancer (Ch. 6)
PRESACRAL TUMORS (789.3)
Overview
Presacral tumors—located in the space between sacrum and rectum—comprise a relatively rare variety of pathologies of
benign, potentially malignant, or malignant character. The complex embryology of that region predisposes to errors. Hence,
two-thirds of lesions are congenital. Risk for malignancy increases with age, reaching 25–40% overall.
Congenital lesions: epidermoid cyst, dermoid cyst, enteric cyst (tailgut, duplication), teratoma, teratocarcinoma.
Neurogenic lesions: chordoma, neurofibroma/sarcoma, neurilemmoma, ependymoma, neuroblastoma, anterior sacral
meningocele.
Osseous: osteoma/chondroma/sarcoma, simple bone cyst, giant cell tumor, Ewing sarcoma, chondromyxosarcoma.
Miscellaneous: metastatic disease, GIST, sarcoma, hemangioma, lymphoma, desmoid, carcinoid, inflammation
(abscess, chronic leak, hematoma).
Epidemiology
Rare, ~0.01% of annual admissions.
Two age peaks: neonate to early childhood (most frequent: teratoma), adults > 40–50 years of age (most frequent:
epidermoid cyst, chordoma).
Symptoms
Children: obvious mass.
Adults:
– Frequently asymptomatic: incidental finding on digital rectal exam or imaging studies.
– Most frequent symptoms: pain (30–40%), pelvic fullness, constipation (25–30%), abscess/discharge (15–20%),
urinary retention (15%), buttock mass (5–10%).
– Suspicious symptoms: recurring deep postanal abscess, recurring anal fistulae without cryptoglandular pathology,
tailbone infection otherwise consistent with pilonidal cyst but in atypical patient, known spinal or anal congenital
deformity.
– Complications: malignant transformation, fistula formation, infection.
– Malignant lesions
high risk of metastatic disease.
Differential Diagnosis
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
Benign cyst.
True presacral tumor: chordoma, giant cell tumor, congenital tumors.
Postsurgical changes: presacral abscess/sinus (anastomotic leak), hematoma.
Recurrent or metastatic cancer.
Postradiation changes (pelvic fibrosis).
Deep postanal abscess (ischioanal abscess).
Meningocele.
Osteomyelitis, pilonidal sinus, tuberculosis, etc.
Pathology
Epidermoid, tailgut, enterogenous cysts (benign, malignant potential if untreated): simple epithelium, no skin appendages.
Sacrococcygeal teratoma (benign with malignant potential): tumor derived from pluripotent stem cell with presence of more
than one germ-cell layer
potential transformation into malignant tumor:
– Common structures: hair, salivary gland, smooth muscle, cartilage, bone, neural tissue, retina, pancreas, thyroid,
teeth, bronchus, fat.
– Rare structures: skeletal muscle, cardiac muscle, kidney, liver tissue.
Dermoid cyst (benign): structural elements derived from ectodermal layer.
Chordoma (malignant): derived from remnants of notochord, locally aggressive malignant tumor with size-dependent sacral
destruction.
Evaluation
REQUIRED MINIMAL STANDARD
History: specific symptoms: bleeding, constipation, change in bowel habits, pain, weight loss, urinary/vaginal symptoms,
preexisting sexual or anal sphincter dysfunction; family history; comorbidities.
Clinical examination:
Digital rectal exam: presacral mass, anterior surface of sacrum/coccyx not palpable.
Rigid sigmoidoscopy: mucosal lesion? Extraluminal compression?
Imaging studies:
Plain x-ray: bony destruction = scimitar sign (caveat: not to be mistaken for thoracic scimitar sign in anomalous
pulmonary venous drainage).
MRI or CT abdomen/pelvis: delineation of soft tissue structures and relation to bone.
Colonic evaluation prior to elective surgery.
ADDITIONAL TESTS (OPTIONAL)
ERUS: involvement of rectal wall?
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
Tumor marker: alpha-fetoprotein (AFP), human chorionic gonadotropin (HCG): little value in differentiating between
benign/malignant.
Aspiration or biopsy: controversial, not routinely recommended or even contraindicated because:
– Risk of seeding
planning such that tract would be excised during surgical resection.
– Risk of meningitis (meningomyelocele).
– Lack of negative predictive value, lack of impact on need for surgery.
Classification
Congenital vs acquired.
Benign vs malignant.
Low vs high location.
Nonoperative Treatment
Inoperable patients due to comorbidities.
Inoperable/incurable due to extent of local tumor
symptom control.
Chordoma or other malignant tumors
role of (neo-)adjuvant chemoradiation?
Operative Treatment
INDICATIONS
Any presacral lesion (unless prohibitive contraindications).
OPERATIVE APPROACH
Low lesion: access through York-Mason or Kraske approach, resection of coccyx, sacral resection required for local
control of chordoma.
High lesion: combined abdominosacral approach—abdominal mobilization of rectum, posterior resection of sacrum,
possible flap closure.
Outcome
Sacral resection relatively safe: pelvic stability preserve S1; sphincter/bladder function preserve S2/S3.
Malignant presacral tumors: intact resection of nonmetastatic chordoma has best prognosis (50% 5-year survival); prognosis
for other malignancies dismal.
Complications: bleeding (presacral veins), wound infections, osteomyelitis, sexual and urinary dysfunction, recurrence.
Follow-Up
Optimization of defecation/fecal control and urinary control.
Surveillance for recurrence.
Role of adjuvant chemoradiation?
Cross-Reference
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
Computed tomography (CT scan) (Ch. 2)
Magnetic resonance imaging (MRI) (Ch. 2)
Kraske approach (Ch. 5)
Resection of presacral tumor/lesion (Ch. 5)
RARE TUMORS
Overview
Although colorectal cancer and anal squamous cell cancer account for the overwhelming majority of tumors encountered in
the colorectal specialty, there are a number of known entities that may never be seen but remain important differential
diagnoses to other conditions.
MALIGNANT MELANOMA
Incidence: ~1% of anorectal malignancies, 2% of all melanomas, third most common melanoma site (after skin,
eye).
Cause: arises from melanocytes in ATZ.
Associated disease: none.
Presentation: polypoid masses of varying size, 60% are black, 40% amelanotic, often mistaken for hemorrhoids.
Treatment options: wide local excision vs abdominoperineal resection. Immunotherapy.
Prognosis: poor (regardless of surgical approach).
KAPOSI SARCOMA
Incidence: overall ~0.5–0.6% of organ transplant recipients; most commonly involving skin etc; extremely rarely
involving anorectum or intestines.
Cause: human herpesvirus-8 (HHV-8) infection in conjunction with immunosuppression (eg, HIV/AIDS, chronic
steroid or immunosuppressant medication, etc).
Associated disease: HIV, immunosuppression (eg, IBD, transplantation).
Presentation: bluish-purple nodules.
Treatment options: improvement of immune status if possible: HIV HAART; IBD proctocolectomy to eliminate
need for immunosuppression. Chemotherapy/potentially radiotherapy, or interferon in patients in whom immune status
cannot be improved.
Prognosis: good if immunosuppression can be improved.
LYMPHOMA
Incidence: GI tract is the most common site of extranodal non-Hodgkin-lymphoma; 1–4% of all GI malignancies
(mostly in stomach and small bowel), only 0.2–0.5% in the colon (cecum) or rectum; male/female ratio 2:1.
Cause: often unknown; viral infection more common, eg, Epstein-Barr virus (EBV) infection in conjunction with
immunosuppression (eg, HIV/AIDS, chronic steroid use, etc).
Associated disease: HIV, immunosuppression (eg, IBD, transplantation).
Presentation: diffuse infiltrative mass, varying degrees of ulcerations, varying size, stricturing, bowel wall thickening
GI symptoms (pain, bleeding, obstruction, mass, etc), B-symptoms (fever, weight loss, sweating). Rare form:
multiple lymphomatous polyposis.
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
Subtypes: B-cell lymphomas (85%): mucosa-associated lymphoid tissue (MALT) lymphoma, mantle cell lymphoma,
Burkitt B-cell lymphoma; T-cell lymphoma (15%).
Treatment options: if confined lymphoma and resection possible without mutilation surgical resection; all others
chemo- and immunotherapy. MALT lymphoma trial of anti-infectious treatment.
Prognosis: good; 5% risk of perforation with induction chemotherapy.
DESMOID
Incidence: 3.5–13% of FAP patients, < 0.01% in patients without FAP.
Cause: gene mutation in 3' region of APC gene between codons 1445 and 1578 benign fibroblastic tumors arising
from mesenchymal primordial germ layer.
Associated disease: FAP with other extracolonic manifestations.
Presentation: usually slow growing (10% grow rapidly) mesenteric, abdominal wall, and retroperitoneal/pelvic soft
tissue mass, often without defined margin; multicentricity but not metastasizing
pain (50%, typically due to bowel
or ureteral obstruction, ischemia), painless mass, or incidental finding.
Treatment options: radical surgical resection. Chemotherapy, imatinib, hormone ablation therapy (eg, tamoxifen),
immunotherapy.
Prognosis: most frequent non–cancer-related cause of death in FAP patients: (1) direct tumor effects (eg, ischemic
bowel, intestinal obstruction, urinary obstruction, fistula, sepsis, etc); (2) surgical mortality. Recurrence rate 65–85%
after resection.
OTHER RARE TUMORS
Small-cell neuroendocrine carcinoma.
Metastases from other primary cancers (eg, lobular breast cancer, lung cancer, etc).
Leukemic or plasmocytoma infiltrates.
Sarcomas (including gastrointestinal stroma tumor).
Vascular tumors: cavernous hemangioma, angiomas, etc.
Cross-Reference
Hemorrhoids (455.X) (Ch. 4)
HIV-associated anorectal diseases (042) (Ch. 4)
Anal cancer (154.2, 154.3) (Ch. 4)
Colorectal cancer—colon cancer (153.X) (Ch. 4)
Gastrointestinal stromal tumor (GIST; 171.9) (Ch. 4)
RADIATION PROCTITIS/ENTERITIS (558.1)
Overview
Acute or chronic side effect from radiation exposure to the pelvis (most commonly for GYN and prostate malignancies).
Typical examples: prostate cancer 6400–7200 cGy, cervical cancer 4500 cGy, endometrial cancer 4500–5000 cGy, rectal
cancer 2500–5040 cGy, bladder cancer 6400 cGy. Very focal rectal injury can result from brachytherapy: seeds (eg,
prostate) or cervical cap. Radiation damage may occur in sites outside of primary therapeutic field: eg, stray radiation may
AccessSurgery | Print: Chapter 4. Diseases and Problems
file:///C|/...RIANA/McGrawHillManual%20ColorectalSurgery%201stEdition/Chapter%204_%20Diseases%20and%20Problems.htm[9/5/2009 19:15:58]
result in diffuse radiation enteritis!
Injury dependent on total dose (typically > 4000 cGy), beam energy and percentage depth dose, fractionation size, field size,
duration of delivery, tissue proliferation, tissue oxygenation.
Radiation damage occurs in two phases:
1. Acute: typically self-limited cytotoxicity from radicals and induced DNA damage to high-turnover cell populations
(intestinal epithelia, bone marrow, skin annexes, etc).
2. Chronic: permanent and irreversible damage through microischemic pathway resulting from obliterative endarteritis,
endothelial degeneration, neovascularization, interstitial fibrosis, epithelial distortion.
Preventive strategies during administration of radiation remain controversial: balsalazide, misoprostol, sucralfate, etc.
Epidemiology
Early injury: in 30–70% of patients undergoing pelvic radiation treatment, < 3–6 weeks of treatment.
Chronic injury: 1–20 years after radiation exposure. Older series: 20–25% incidence; newer series: 3–8% (likely the result
of improved radiation calculation/simulation techniques).
Symptoms
Acute proctitis: diarrhea, passage of mucus and blood per rectum, urgency/incontinence, tenesmus, pain, perianal dermatitis.
Systemic effects uncommon and more likely related to general treatment side effects: anemia, anorexia, malnutrition/weight
loss. Resolution of acute symptoms after 6–12 weeks.
Chronic radiation proctitis: bleeding (ulcerations, telangiectasias), diarrhea, mucous discharge per rectum,
urgency/incontinence (decreased reservoir volume and compliance), tenesmus, perianal dermatitis. Complications include:
hemorrhage, obstructive symptoms (stricture formation), fistula formation (eg, rectovaginal fistula), incontinence (nerve
damage, sphincter damage, loss of reservoir). Increased risk of secondary malignancy.
Differential Diagnosis
Tumor recurrence, IBD (ulcerative colitis, Crohn disease, indeterminate colitis), ischemic colitis, infectious colitis (including
pseudomembranous C difficile colitis), STD proctitis (eg, lymphogranuloma venereum, gonorrhea), IBS.
Caveat: avoid fast-track "hemorrhoid" diagnosis/treatment in previously radiated rectum!
Pathology
MACROSCOPIC
Congested/edematous mucosa, necrosis, ulcerations/fistula opening, telangiectasias, strictures, bowel foreshortening.
MICROSCOPIC
Acute injury: epithelial ulcerations, meganucleosis, inflammation in the lamina propria, lack of mitotic activity.
Chronic injury: subintimal arteriolar fibrosis (endangitis obliterans), endothelial degeneration, fibrosis of the lamina
propria, crypt distortion, hypertrophy of myenteric plexus of Auerbach.
Evaluation