Endometriosis-associated colorectal carcinosarcoma: A case report and review of the literature

Colorectal Carcinoma With Sarcomatoid Components: Report of 15 Cases and Literature Review of an Exceedingly Rare Carcinoma Subtype

Colorectal carcinoma with sarcomatoid components (which includes so-called carcinosarcomas and sarcomatoid carcinomas) is a rare subtype with 50 reported cases in the literature and overlapping criteria with undifferentiated carcinoma. We collected and described 15 cases from 10 men and 5 women, with a mean age of 66 years. Symptoms included abdominal pain and gastrointestinal bleeding. Most tumors presented in the rectosigmoid region, with a mean size of 8.2 cm. The sarcomatoid component, on average, represented 58% of the tumors and took many forms, including spindled (10 cases), anaplastic (9 cases), and rhabdoid (3 cases); one case showed osteoid matrix. Tumor budding was usually high, and tumor-infiltrating lymphocytes were usually low. The sarcomatoid component was keratin-positive in 10 cases. One case showed loss of mismatch repair protein expression, and 2 cases showed SMARCA4 loss (1 also with SMARCA2 loss). Molecular testing identified mutations in KRAS (n=1), NRAS (n=2), BRAF (n=2), APC (n=1), and TP53 (n=1) in a few cases. Tumors often presented at advanced stage, with 11 cases pT4, 9 cases with nodal metastases, and 7 cases with distant metastases. Follow-up was available for 10 cases (median: 2 months), with 2 alive without disease, 3 alive with disease, and 5 dead. Our findings roughly corresponded with those in previously reported cases. Colorectal carcinoma with sarcomatoid components is rare and aggressive, with a poor prognosis for many patients. We suggest that spindled cells, anaplasia, heterologous elements, and/or a component with definable sarcomatous lineage be used to distinguish colorectal carcinoma with sarcomatoid components from undifferentiated carcinoma.

Malignant Mixed Mullerian Tumor Arising from Endometriosis in the Groin: A Case Report and Literature Review

This was a 57-year-old woman who presented with mild discomfort in the right groin. Physical examination revealed a mass in the right groin, and by ultrasound, the mass was hypoechoic and solid with some internal vascularity. The clinical differential diagnosis included lymphoma and others. The mass was excised for pathologic evaluation. Gross examination of the specimen revealed a 3 × 2.4 × 2 cm, solid and cystic mass. Microscopically, it was a biphasic tumor consisting of carcinomatous and sarcomatous components. The tumor was seen contiguous with endometriosis and atypical endometrioid hyperplasia. The histologic findings were consistent with malignant mixed Mullerian tumor (MMMT) arising from endometriosis in the right groin. The tumor involved the resection margin. Subsequent chest/abdominal/pelvic computed tomography did not reveal evidence of tumors, and diagnostic peritoneal/pelvic laparoscopy did not show diseases. Postoperatively, the patient received 6 cycles of chemotherapy consisting of carboplatin and paclitaxel, followed by radiation in the right groin. Malignant transformation from endometriosis occurs in less than 1% of endometriosis cases, and about 80% of the transformed tumors occur in the ovaries. The most commonly transformed malignant tumors are endometrioid and clear cell carcinomas, with rare adenosarcoma and endometrial stromal sarcoma reported. To our knowledge, we are reporting the first case of MMMT arising from endometriosis in the groin.