an unusual cause of lower gastrointestinal bleeding dr. lee hing yin harry queen elizabeth hospital...
TRANSCRIPT
An unusual cause of lower gastrointestinal bleeding
Dr. Lee Hing Yin HarryQueen Elizabeth Hospital
8th November 2014Joint Hospital Surgical Grandround
F/47• History of left ovarian dermoid cyst with left salpino-
oopherectomy performed before in private
• Otherwise no significant past health
• On & off per-rectal bleeding since Dec 2013
• Seen GOPC with some treatment given but symptoms persist
• Emergency admitted in Jan 2014 for PR bleeding with fresh blood
• No report of red flag symptoms
• Upon admission she was stable and afebrile
• Examination unremarkable. No anorectal lesion.
• Haemoglobin mildly dropped from 11.1 to10.4
• OGD performed showing no bleeding source
• Offered colonoscopy for early workup
Colonoscopy Feb 2014
• 2cm hard sessile polyp with stony hard consistency at sigmoid colon
• Wide base and decided not for polypectomy
• Biopsy taken
Biopsy result
• Summary pathology: no evidence of malignancy
• Microscopic examination:
1. A piece of intestinal mucosa and a piece of inflamed mucosa covered by stratified squamous epithelium
2. ? Squamous metaplasia covering an underlying lesion
Colonoscopy March 2014
• Scope to tumour
• Pedunculated tooth-like lesion at 28-30cm
• Biopsy taken from the base of lesion
• SPOT injected distal to the lesion
Biopsy result• Microscopic examination
• Multiple inflamed mucosa covered by stratified squamous epithelium with keratinization
• Vacuolated cells seen, suggestive of sebaceous cells
• In view of known history of bilateral dermoid cyst of ovaries, teratoma is a ddx
• Another ddx: underlying lesion with squamous metaplasia
Computer tomography• At least 3 small calcified nodu
lar crown-like inside lumen of sigmoid colon
• No obvious extra-luminal soft tissue mass seen
• No enlarged intra-abdominal lymph node
• No ascites
Laparoscopic surgery (27.3.2014)
• Right ovary dermoid ovarian cyst wrapping around sigmoid colon, tightly adhered and unable to simply dissecting out
• Gynaecologist was on-table consulted with right salpingo-oopherectomy performed
• Colorectal surgeon performed laparoscopic sigmoidectomy
• En-bloc resection of sigmoid and right ovary
Extra-luminal view
Intra-luminal view
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 gland
• No cellular atypia
• No immature component
• Resection complete and margins were clear
• Literally a case of “Tooth bleeding” or “Gum bleeding"
• No recurrence of PR bleeding post-op
• She was referred to gynaecologist for further follow up afterwards
• First encounter of such presentation
• Ovarian teratoma by itself is not uncommon
• Colonic teratoma / involvement is extremely rare
Colonic teratomaReview of literature
Teratoma is one of the germ cell tumour
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
Primordial germ cellPrimordial germ cell
Undifferentiated germ cellUndifferentiated germ cell
DifferentiationDifferentiation
Extra-embryonicExtra-embryonic Intra-embryonicIntra-embryonic
Dysgerminoma
Embryonal carcinoma
yolk sac tumourchoriocarcinoma
mature teratomaimmature teratoma
Histological classification reflects the degree of differentiation of cells before they degenerate malignantly
Background of teratoma
• Differentiated form of germ cell tumour
• Can differentiate into different germ layers (endoderm, ectoderm, mesoderm)
• Potentially composed of one or more germ layer, can be mono-dermal or poly-dermal
Grading / degree of differentiation of teratoma
• Depend on degree of differentiation
• Can 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, muscle
• Ectoderm: neuroglia, ganglion, keratinized stratified squamous epithelium, epidermis, hair, sebaceous, apocrine sweat gland, choroid, melanin-pigment
• Endoderm: bronchus, liver, thyroid, pancreas, salivary gland
• Mesoderm: smooth muscle fibre, vessel, fibrous tissue, adipose tissue, cartilage, bone, ciliated epithelium
• Dermoid 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
Location of lesion
• Appear most commonly in gonads and rare in other sites
• Extra-gonadal site being rare but potential sites included:
• anterior mediastinum, retro-peritoneum, central nervous system e.g. pineal gland, sacro-coccygeal
GIT teratoma• GIT (gastro-intestinal tract) being the extra-gonadal site is ext
remely rare
• Can 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 teratoma
• Upon literature search, in English literature, total cases reported difficult to ascertain, but certainly around 100 cases were reported since 1850
• Most are isolated case reports, not even up to case series
Primary (Congenital)
• Anorectal teratoma
• Ileo-cecal teratoma
As the totipotent cell moves along dorsal mesentery of hindgut, this explains why teratoma usually affects distal bowel
Secondary
• From ovarian teratoma (as intra-abdominal and also in proximity to bowel loops)
GIT teratoma
Primary (Congenital)
• Anorectal teratoma
• Ileo-cecal teratoma
As the totipotent cell moves along dorsal mesentery of hindgut, this explains why teratoma usually affects distal bowel (terminal small bowel + large bowel)
Secondary
• From ovarian teratoma (as intra-abdominal and also in proximity to bowel loops)
GIT teratoma
Secondary colonic teratomaBackground of Ovarian teratoma
• Ovarian teratoma accounts for 10-20% of all ovarian tumour, not an uncommon disease
• United states - 5 cases per 100,000 populationNo racial predisposition is evident
• Age of presentation is wide (10-70years), but majority belongs to reproductive age
• Up to 90% of ovarian teratoma is mature typei.e. benign, in the form of dermoid cyst
• 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 7cm
Fertil Steril. 1997 Sep;68(3):501-5.
Proposed pathogenesis of penetration into colonic wall
• Iatrogenic e.g. implantation of ovarian tissue into colonic wall during intra-abdominal operation
• Repeated acute / chronic local infection or inflammation between ovaries and colonic walls (e.g. diverticulum) resulting in fistulation
• Fibrosis 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
• Variety of presentation
• Mostly involve gynaecologist in the first place
• Presentation that may involve surgeon includes:
• Acute abdomen e.g complication with rupture, perforation, torsion, infection that may mimic surgical pathology
• Complication of ovarian dermoid cyst is torsion (30%)
• Rupture is rare (<1%), as dermoid cyst is not a thin cyst and is well capsulated
• Penetration / fistulation into other organs e.g. rectum / colon / bladder that cause symptoms
• Abdominal mass
• Chronic abdominal pain
• Bleeding is less common
• No specific investigations
• X-ray may review calcification in para-axial region of pelvis
• No tumour marker
• Biopsy with stratified squamous mucosa will alarm the possibility of teratoma component
• Squamous histology in colon is rare
• Differential diagnosis of squamous histology in colon
• Adenoma with squamous metaplasia
• Squamous cell carcinoma (associated with ulcerative colitis, post-RT)
• Adeno-squamous carcinoma
• 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 >6cm
• Usually SCC will be the more common malignant transformation
• Poor prognosis and if stage 2 and above
• 5-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 colon
World J Gastroenterol 2011 August 28; 17(31): 3659-3662Image captured from the journal
• Treatment modality varied
• For benign disease pre-menopausal, resection en-bloc with involved organ + preserved fertility is the main goal
• Advocate TAH-BSO in post-menopausal women
• During operation, spillage has to be avoided due to marked chemical peritonitis
• In 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.
Management
• 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.
Primary (Congenital)
• Anorectal teratoma
• Ileo-cecal teratoma
As the totipotent cell moves along dorsal mesentery of hindgut, this explains why teratoma usually affects distal bowel (terminal small bowel + large bowel)
Secondary
• From ovarian teratoma (as intra-abdominal and also in proximity to bowel loops)
GIT teratoma
Anorectal teratoma• Only 51 cases in English literature reported between 1865 - 2008
• All cases located within 15cm of anal verge i.e. termed anorectal teratoma and in the form of cystic lesion
• DDx 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
• Congenital nature
• Both 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.
• 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 submucosa
• Majority of cases, structurally-wise:
• Solitary
• Pedunculated and protruding
• Can have hair, tooth, finger-like projection
• Located at anterior wall of rectum
• Usually sizeable on presentation, smallest 2cm on 1st medical attention up to occupying whole pelvic space
• Macroscopically and microscopically confined within rectum, with well preserved tissue plane and encapsulated
• Biopsy showing squamous epithelium is strong indicator of teratoma
• No specific features on imaging
• Most are thought to be benign
• Rarity of cases and lack of long term follow-up, malignant risk difficult to ascertain
• Some case reports and series, estimated rate can be up to 15% malignant risk
• 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.
Ileocecal teratoma• Total reported case in literature <10 since 1850
• Can only acquire 2 case reports concerning ileocecal involvement
• Take the form of mesenteric cyst
1. Peri-appendiceal dermoid cyst causing RLQ pain + partial IO; requiring small bowel resection + anastomosis. Bilateral ovaries normal
2. Dermoid cyst involving the cecal mesentry required laparoscopic enucleation.
Summary• Overall colonic teratoma is rare disease entity
• More common presentation involving surgeon will be female with dermoid cyst complications with adjacent organ involvement
• Stratified squamous mucosa is a signature of disease on biopsy, especially if you can see specialised tissue e.g. hair, tooth
• Most benign cases can be surgically cured with en-bloc resection
Thank you!