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!