ABSTRACT
Plexiform schwannoma is a benign peripheral nerve sheath tumor composed exclusively of Schwann cells arranged in a plexiform pattern. Most plexiform schwannomas are skin tumors and visceral localization is very rare. To our knowledge, there are six cases localized in visceral organs. We describe herein the first known case of plexiform schwannoma of the rectum resected by endoscopic submucosal dissection (ESD). A 77-year-old woman presented with a short history of anal pain. Sigmoidoscopy demonstrated a submucosal tumor, 20 mm in diameter, of the rectum below the peritoneal reflection (Rb). We resected the tumorby ESD. The tumor consisted of multiple white nodules in the submucosal layer. Microscopic examination revealed that the tumor was composed mainly of Antoni A tissue, compatible with conventional schwannoma. Immunohistochemically, the tumor was positive for S-100, and negative for α-smooth muscle actin, c-kit and CD-34. No evidence of recurrence has been found in 2 years of follow up.
Subject(s)
Neurilemmoma/pathology , Rectal Neoplasms/pathology , Actins/metabolism , Aged , Dissection/methods , Endoscopy, Digestive System , Female , Humans , Immunohistochemistry , Neurilemmoma/metabolism , Neurilemmoma/surgery , Rectal Neoplasms/metabolism , Rectal Neoplasms/surgery , S100 Proteins/metabolism , SigmoidoscopyABSTRACT
We report a case of 72-year-old man found to have a primary malignant melanoma in the jejunum. The patient was noted to be anemic and had lower abdominal pain on his visit to the Department of Gastroenterology. However, an upper gastrointestinal series and colonofiberscopic examination revealed no abnormalities. After clinical examinations, the radiological workup, which included CT, X-ray of the small intestine and single-balloon enteroscopy, revealed an intraluminal polypoid tumor, with a patchy light gray and black pattern. Pre-operative biopsy specimens revealed a malignant melanoma. Segmental intestinal resection with regional lymph node dissection was performed. The tumor size was 7.0×9.5×5.8cm. Nodal metastasis was seen only in the mesenteric node draining from the tumor-bearing intestinal segment (stage IIIa). Adjuvant chemotherapy with dacarbazine, nimustine hydrochloride and vincristine sulfate was performed, and the patient was able to recover his level of activity of daily living for 6 months.
