Extrauterine primary peritoneal endometriosis associated tumor of rectosigmoid

Sir, A 46-year-old female, with history of hysterectomy 10 years ago, presented in 2009 with complaints of constipation of few months duration. Colonoscopy revealed an extra-mucosal stricture in sigmoid colon. The mucosa looked unremarkable. Computed tomography scan revealed two separate, intramural nodular masses in muscle and peritoneal coats with the intervening segment unremarkable. There also were innumerable smaller nodules all over the pelvic peritoneum, in general, and pouch of Douglas, in particular. The affected segment was resected. The stricture areas showed two distinct nodular masses, measuring 4.0 and 2.5 cm in maximum dimension, respectively. Microscopically, the tumor cells were small, round, monomorphic like stromal cells of proliferative phase of endometrium. The tumor cell nodules were pushing tongue-like extensions into tissue spaces, and limited to muscle and peritoneal coats. Stroma showed spiral arterioles [Figure 1, Figures 2 and 3]. Cells were CD10 positive, ER positive, PR positive, CD117 negative, Vimentin positive and SMA negative. Diagnosis of classic type of endometrial stromal sarcoma (ESS) infiltrating a segment of sigmoid was obvious. Endometriosis associated intestinal tumors (EAIT) are seen as a rare complication of pelvic peritoneal endometriosis. Rectosigmoid wall is the most frequently infiltrated segment responsible for clinical symptoms. EAIT are a spectrum of tumors varying from glandular to stromal elements of Mullerian duct origin, complicating endometriosis. Of these, endometroid adenocarcinoma is the most frequently seen and ESS the least. [,] Awareness of these tumors in a particular clinical setup needs to be appreciated. Preoperative clinical diagnosis is extremely difficult. In a postmenopausal female, often giving a past history of hysterectomy, presenting with colonic complaints referable to extramucosal, intramural mass producing stricture deformity, EAIT needs to be considered vis-à-vis a primary colonic/mesenteric pathology. Diagnosis of ESS is exclusively based on surgical pathological examination. Diagnosis of classic ESS on routine H and E sections offers no difficulty. The specific immunophenotype emphasizing ESS, namely, CD10 positive, ER and PR positive, CD 117 negative, offers additional help when ESS shows metaplastic changes including glandular and/or mesenchymal tissues. The immunophenotype also offers help in differentiation with the other look-alike tumors. [,] Presence of high frequency of gene fusion of JAZFI-JJAZI as a result of t(7:17) (p15:q21), is a frequent, although nonuniform feature of ESS including its metaplastic variants. This may be applicable for diagnostic use in select situations. [] Acknowledgment We are grateful to Dr. Ruchi Sachdeva, Scientific Officer, Department of Pathology, CHL-Apollo Hospitals, Indore, Madhya Pradesh, India, for her technical help in the preparation of the manuscript. REFERENCES - 1. Yantiss RK, Clement PB, Young RH. Neoplastic and pre-neoplastic changes in gastrointestinal endometriosis: A study of 17 cases Am J Surg Pathol. 2000;24:513–24 - 2. Slavin RE, Krum R, Van Dinh T. Endometriosis-associated intestinal tumors: A clinical and pathological study of 6 cases with a review of the literature Hum Pathol. 2000;31:456–63 - 3. McCluggage WG, Ganesan R, Herrington CS. Endometrial stromal sarcomas with extensive endometrioid glandular differentiation: Report of a series with emphasis on the potential for misdiagnosis and discussion of the differential diagnosis Histopathology. 2009;54:365–73 - 4. Bhargava R, Shia J, Hummer AJ, Thaler HT, Tornos C, Soslow RA. Distinction of endometrial stromal sarcomas from 'hemangiopericytomatous' tumors using a panel of immunohistochemical stains Mod Pathol. 2005;18:40–7 - 5. Nucci MR, Harburger D, Koontz J, Dal Cin P, Sklar J. Molecular analysis of the JAZF1-JJAZ1 gene fusion by RT-PCR and fluorescence in situ hybridization in endometrial stromal neoplasms Am J Surg Pathol. 2007;31:65–70