Ch. 17 pt 3 Flashcards
what is the pectinate line?
can you see it?
transition of postalantoic hindgut to proctodeum
=formed by anal valves at the inf-most end of anal column
=anal pecten (aka transitional zone)
see on slight retraction of anal canal skin AFTER under anesthesia
What are characteristics of the anal canal above the pectinate line
=lined w/ columnar epithelium
anal columns = 6-10 longitudinal mucosal folds in upper part of anal canal
bottom of columns = crypts - open anal glands and papillae
*infxn of anal gland = initial event in causation of perianal abscess and fistula-in-ano
what are the possible cancers of the anal canal
above pectinate line = adenocarcinoma
below = SCC (often associated w/ HPV)
-can spread to superficial inguinal LN
what are characteristics of the anal canal below the pectinate line
=stratified squamous
(==> squamous metaplasia bc the parts above the line change from columar to squamous)
Anal canal & low rectal cancers can …
infiltrate the anorectal ring & cause incontinence
(contraindication for sphincter perservation)
what is the viral cause for change in histology above the pectinate line
HPV
(precursor lesions = condyloma acuminatum - anal warts)
What are RF, presentation, morphology and Tx for hemorrhoids
RF: elevated venous pressure (constipation- straining when defecating, pregnancy, portal HTN)
present w/ pain, itching, rectal bleed (bright red blood)
morphology = thin-walled, dilated, submucosal vessels that protrude beneath the anal/rectal mucosa
Tx: excise, sclerotherapy, ligate, SRG
differentiate external and internal hemorrhoids
external = BELOW pectinate line (inferior hemorrhoidal plexus) ; painful
internal = above line (superior hemorrhoidal plexus); painless (insensitive canal mucosa) - intervene w/ injection w/ schelocant or ligate w/ rubber band W/O anesthesia
what can rectal exams be used for
prostate exam ( transrectal Bx)
check uterus
appendicitis
ascess occult blood loss
what is the populations that appendicitis presents in most?
MC= teens/young adults (M>F slightly)
difficult to diagnose at extremes of age
along with appendicitis, what can be on your DDx for RLQ pain
Meckel diverticulum (RLQ)
mesenteric lymphadenitis
acute salpingitis (adults, gonoccal or other organism)
ectopic pregnancy (esp R)
mittelschmirtz (pain mid cycle)
what is the clinical presentation and pathogenesis of a pt w/ appendicitis
periumbilical pain; usually localized to RLQ - McBurney’s Point (2/3 away from ASIS)
N/V, low grade fever, mild leukocytosis
pathogenesis: obstruction of the lumen by stool (fecalith), tumor worms (pinworms) –> increase intraluminal P ==> cause bacterial prolif, ischemia, inflam response –> edema & neutrophilic infiltration (–> supportive therapy)
what are examples of other tumors of the appendix
well differentiated neuroendocrine tumor (Carcinoids) = 2nd MC site
conventional adenomas & carcinomas
mucinous neoplasms - benign/malignant
what is pseudomyxoma peritonei
syndrome of progressive intraperitoneal accumulation of mucinous ascites related to a mucin producing neoplasm
MCC = mucinous tumor of the appendix
what are the possible infxns of the peritoneum due to bacteria/chemicals
Perforation of abd viscera –> leakage of luminal material –> infxn & immune activation
Sterile peritonitis: bile or pancreatic enzyme leakage
Perforations/rupture of biliary system –> highly irritating peritonitis; complicated by bacterial superinfxn
Acute hemorrhagid pancreatitis: leakage of pancreatic enzymes & at necrosis –> bacterial spreads to the peritoneal cavity
Foreign material: introduced surgically (talc, sutures) –> induce foreign body type granuloma and fibrous scarring
Endometriosis: irritation due to hemorrhage
Ruptured demoid cysts: release of keratins –> induce intense granulomatous rxn
What is sclerosing retroperitnoitis (aka idiopathic retroperitoneal fibrosis, aka ormond dz)
sxs
population
bilateral fibroinflam process that surrounds the abd aorta & ureters (can arise 2ndary to radiation or tumors, esp lymphoma)
can appear due to IgG4-related dz
elevated ESR or C-reactive protein; MC = back & abd pain
middle aged - elderly, Males
common 2ndary finding = acute renal failure
