Presentation on theme: "An unusual cause of lower gastrointestinal bleeding"— Presentation transcript:
1 An unusual cause of lower gastrointestinal bleeding Dr. Lee Hing Yin HarryQueen Elizabeth Hospital8th November 2014Joint Hospital Surgical Grandround
2 F/47History of left ovarian dermoid cyst with left salpino- oopherectomy performed before in privateOtherwise no significant past healthOn & off per-rectal bleeding since Dec 2013Seen GOPC with some treatment given but symptoms persistEmergency admitted in Jan 2014 for PR bleeding with fresh blood
3 No report of red flag symptoms Upon admission she was stable and afebrileExamination unremarkable. No anorectal lesion.Haemoglobin mildly dropped from 11.1 to10.4OGD performed showing no bleeding sourceOffered colonoscopy for early workup
4 Colonoscopy Feb 20142cm hard sessile polyp with stony hard consistency at sigmoid colonWide base and decided not for polypectomyBiopsy taken
6 Biopsy result Summary pathology: no evidence of malignancy Microscopic examination:A piece of intestinal mucosa and a piece of inflamed mucosa covered by stratified squamous epithelium? Squamous metaplasia covering an underlying lesion
7 Colonoscopy March 2014 Scope to tumour Pedunculated tooth-like lesion at 28-30cmBiopsy taken from the base of lesionSPOT injected distal to the lesion
8 Biopsy result Microscopic examination Multiple inflamed mucosa covered by stratified squamous epithelium with keratinizationVacuolated cells seen, suggestive of sebaceous cellsIn view of known history of bilateral dermoid cyst of ovaries, teratoma is a ddxAnother ddx: underlying lesion with squamous metaplasia
9 Computer tomographyAt least 3 small calcified nodular crown-like inside lumen of sigmoid colonNo obvious extra-luminal soft tissue mass seenNo enlarged intra-abdominal lymph nodeNo ascites
11 Laparoscopic surgery (27.3.2014) Right ovary dermoid ovarian cyst wrapping around sigmoid colon, tightly adhered and unable to simply dissecting outGynaecologist was on-table consulted with right salpingo- oopherectomy performedColorectal surgeon performed laparoscopic sigmoidectomyEn-bloc resection of sigmoid and right ovary
14 Pathology Mural polypoid mass harbouring three teeth Part of the ovary and colonic wall is involved by mature cystic teratoma (a.k.a. dermoid cyst).Teratoma containing teeth, adipose tissue, epidermis and sebaceous glandNo cellular atypiaNo immature componentResection complete and margins were clear
15 Literally a case of “Tooth bleeding” or “Gum bleeding" No recurrence of PR bleeding post-opShe was referred to gynaecologist for further follow up afterwards
16 First encounter of such presentation Ovarian teratoma by itself is not uncommonColonic teratoma / involvement is extremely rare
19 How do they arise? “Wandering germ cell theory” During embryogenesis (4-6 weeks), toti- potent primordial germ cell migrates from yolk sac to the gonads via dorsal mesentry of the hindgut.Sequestration of stem cell can be possible during migration along the pathway.This is to explain the potential pathophysiology of germ cell tumour being extra-gonadal
20 Undifferentiated germ cell Histological classification reflects the degree of differentiation of cells before they degenerate malignantlyPrimordial germ cellDysgerminomaUndifferentiated germ cellEmbryonal carcinomaDifferentiationExtra-embryonicIntra-embryonicyolk sac tumourmature teratomachoriocarcinomaimmature teratoma
21 Background of teratoma Differentiated form of germ cell tumourCan differentiate into different germ layers (endoderm, ectoderm, mesoderm)Potentially composed of one or more germ layer, can be mono-dermal or poly-dermal
22 Grading / degree of differentiation of teratoma Depend on degree of differentiationCan be classified into mature (80%), immature (16%) and teratoma with malignant transformation (4%)Sometimes tissue differentiation can be very specialised and form e.g. hair, tooth, eyeball, skin, bone, muscleEctoderm: neuroglia, ganglion, keratinized stratified squamous epithelium, epidermis, hair, sebaceous, apocrine sweat gland, choroid, melanin-pigmentEndoderm: bronchus, liver, thyroid, pancreas, salivary glandMesoderm: smooth muscle fibre, vessel, fibrous tissue, adipose tissue, cartilage, bone, ciliated epitheliumDermoid cyst - usually refers to mature teratoma of ovaries but can apply to other sites, a special form of mature teratoma in which ectodermal tissue predominates
23 Location of lesionAppear most commonly in gonads and rare in other sitesExtra-gonadal site being rare but potential sites included:anterior mediastinum, retro-peritoneum, central nervous system e.g. pineal gland, sacro-coccygeal
24 GIT teratomaGIT (gastro-intestinal tract) being the extra-gonadal site is extremely rareCan either be primary (arise de-novo inside bowel, congenital) or secondary (acquired, complicating from teratoma of other sites e.g. ovarian teratoma fistulating into colon)Secondary will be commoner than primary teratomaUpon literature search, in English literature, total cases reported difficult to ascertain, but certainly around 100 cases were reported since 1850Most are isolated case reports, not even up to case series
25 GIT teratoma Primary (Congenital) Anorectal teratoma Ileo-cecal teratomaAs the totipotent cell moves along dorsal mesentery of hindgut, this explains why teratoma usually affects distal bowelSecondaryFrom ovarian teratoma (as intra-abdominal and also in proximity to bowel loops)
26 GIT teratoma Primary (Congenital) Anorectal teratoma Ileo-cecal teratomaAs the totipotent cell moves along dorsal mesentery of hindgut, this explains why teratoma usually affects distal bowel (terminal small bowel + large bowel)SecondaryFrom ovarian teratoma (as intra-abdominal and also in proximity to bowel loops)
27 Secondary colonic teratoma Background of Ovarian teratoma Ovarian teratoma accounts for 10-20% of all ovarian tumour, not an uncommon diseaseUnited states - 5 cases per 100,000 population No racial predisposition is evidentAge of presentation is wide (10-70years), but majority belongs to reproductive ageUp to 90% of ovarian teratoma is mature type i.e. benign, in the form of dermoid cyst
28 up to 15% can be bilateral disease Slow growing tumour One prospective analysis focusing on the growth rate suggest it is 1-2mm/year for pre-menopausal women. Zero growth rate was observed in post- menopausal women. Potential explanation is due to hormonal triggering of sebum secretion in dermoid cyst.In the setting of colonic involvement, average size on presentation is 7cmFertil Steril Sep;68(3):501-5.
29 Proposed pathogenesis of penetration into colonic wall Iatrogenic e.g. implantation of ovarian tissue into colonic wall during intra-abdominal operationRepeated acute / chronic local infection or inflammation between ovaries and colonic walls (e.g. diverticulum) resulting in fistulationFibrosis and macrophages infiltration (foreign body reaction) were evident as quoted in some study, suggest the underlying presence of chronic inflammatory process.In the setting of malignant transformation, local invasion is possible
30 Variety of presentation Mostly involve gynaecologist in the first placePresentation that may involve surgeon includes:Acute abdomen e.g complication with rupture, perforation, torsion, infection that may mimic surgical pathologyComplication of ovarian dermoid cyst is torsion (30%)Rupture is rare (<1%), as dermoid cyst is not a thin cyst and is well capsulatedPenetration / fistulation into other organs e.g. rectum / colon / bladder that cause symptomsAbdominal massChronic abdominal painBleeding is less common
31 No specific investigations X-ray may review calcification in para-axial region of pelvisNo tumour markerBiopsy with stratified squamous mucosa will alarm the possibility of teratoma componentSquamous histology in colon is rareDifferential diagnosis of squamous histology in colonAdenoma with squamous metaplasiaSquamous cell carcinoma (associated with ulcerative colitis, post- RT)Adeno-squamous carcinoma
32 Usually SCC will be the more common malignant transformation Small risk of malignant transformation with subsequent invasion + fistulation into other organ (<1%)Usually associated with post-menopausal status, rapid growth in size and large size >6cmUsually SCC will be the more common malignant transformationPoor prognosis and if stage 2 and above5-year survival of stage 2 disease 33.8%Prince of Wales Hospital reported one extreme rare case of gas-filled abdominal mass in F/85 caused by malignant transformation of an pre-existing ovarian teratoma into SCC and fistulated to the sigmoid colonWorld J Gastroenterol 2011 August 28; 17(31): Image captured from the journal
33 Management Treatment modality varied For benign disease pre-menopausal, resection en-bloc with involved organ + preserved fertility is the main goalAdvocate TAH-BSO in post-menopausal womenDuring operation, spillage has to be avoided due to marked chemical peritonitisIn pathology report, look out for immaturity of tissue (immature type) or any malignant atypic cells (malignant transformation) in which formal staging / chemotherapy may be needed.
34 Prognosis theoretically we expected complete cure after surgery if benign From literature, because of rarity of cases and lack of long term follow-up. Reported no recurrence up to 5 years.
35 GIT teratoma Primary (Congenital) Anorectal teratoma Ileo-cecal teratomaAs the totipotent cell moves along dorsal mesentery of hindgut, this explains why teratoma usually affects distal bowel (terminal small bowel + large bowel)SecondaryFrom ovarian teratoma (as intra-abdominal and also in proximity to bowel loops)
36 Anorectal teratomaOnly 51 cases in English literature reported betweenAll cases located within 15cm of anal verge i.e. termed anorectal teratoma and in the form of cystic lesionDDx of cystic lesion around rectum:Developmental cyst e.g. epidermoid, tailgut, duplication cyst.Others including sacrococcygeal teratoma, sacral meningocele, anal duct cyst, necrotic rectal leiomyosarcoma, cystic lymphangioma, pyogenic abscess, sacral chordoma, TB
37 Congenital natureBoth can occur neonatally (pre-natal USG may be able to pick up if large) and in adults. Age of presentation varies (6-73yr in adult series)Majority female patient (98%). Only one male.
38 Presentation usually involve pressure symptoms or bowel symptoms In theory, can arise from any layer of the rectum. In case reports with documented EUS findings, lesion usually arise from muscularis propia or submucosaMajority of cases, structurally-wise:SolitaryPedunculated and protrudingCan have hair, tooth, finger-like projectionLocated at anterior wall of rectumUsually sizeable on presentation, smallest 2cm on 1st medical attention up to occupying whole pelvic space
39 Macroscopically and microscopically confined within rectum, with well preserved tissue plane and encapsulatedBiopsy showing squamous epithelium is strong indicator of teratomaNo specific features on imaging
40 Most are thought to be benign Rarity of cases and lack of long term follow-up, malignant risk difficult to ascertainSome case reports and series, estimated rate can be up to 15% malignant risk
41 Treatment will aim for margin-clear resection Some case reports advocated endoscopic removal if tumour pedunculated and reported no recurrence (Follow-up up to 3 years, mind that the layer of tumour arising is likely submucosal or beneath)For more externally located lesion, need surgical resection depending on anatomy.
42 Ileocecal teratoma Total reported case in literature <10 since 1850 Can only acquire 2 case reports concerning ileocecal involvementTake the form of mesenteric cystPeri-appendiceal dermoid cyst causing RLQ pain + partial IO; requiring small bowel resection + anastomosis. Bilateral ovaries normalDermoid cyst involving the cecal mesentry required laparoscopic enucleation.
43 Summary Overall colonic teratoma is rare disease entity More common presentation involving surgeon will be female with dermoid cyst complications with adjacent organ involvementStratified squamous mucosa is a signature of disease on biopsy, especially if you can see specialised tissue e.g. hair, toothMost benign cases can be surgically cured with en- bloc resection