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!