[A case of rectovaginal metastasis 6 years after initial resection of extra-gastrointestinal stromal tumor of vulvar origin].

A 53-year-old woman who had undergone excision of KIT-positive extra-gastrointestinal stromal tumor (EGIST) of the vulva 6 years ago presented to our hospital due to a positive fecal occult blood test. Colonoscopy revealed a submucosal tumor in the rectum ventral side. In addition, computed tomography and magnetic resonance imaging revealed a tumor in the rectovaginal septum. For diagnostic and therapeutic purposes, the tumor was resected via the perineal approach. The resected specimen analysis revealed a KIT-positive gastrointestinal stromal tumor (GIST). Following immunopathological and genetic mutation identifications, GIST of the rectovaginal septum from vulva EGIST metastasis was diagnosed. It is important to consider primary GIST and metastatic GIST as differential diagnoses in the case of a rectal submucosal tumor detected by endoscopy.

[Intraductal papillary neoplasm of bile duct developed in a patient with IgG4-related sclerosing cholangitis, autoimmune pancreatitis, and myasthenia gravis].

In the course of treatment for myasthenia gravis, enlargement of a cystic mass in the liver with peripheral bile duct dilation, diffuse pancreatic enlargement, and serum IgG4 level elevation was identified in a 65-year-old man. Following the diagnosis of autoimmune pancreatitis, a left hepatectomy was performed because of suspected malignancy of the cystic lesion. Analysis of the resected specimen revealed the cystic lesion to be a dilated bile duct. Intraductal papillary tumor comprising fibrovascular stalks covered by neoplastic epithelium was identified in the lesion. Infiltration of IgG4-positive plasma cells was discovered around the cystic lesion. Finally, a diagnosis of intraductal papillary neoplasm of bile duct with IgG4-related sclerosing cholangitis was made. Autoimmune diseases, including IgG4-related diseases, require careful observation because of their potential for malignancy.