Anaplastic carcinoma showing rhabdoid features combined with mucinous cystadenocarcinoma of the pancreas.

A 52-year-old Japanese woman presented with complaints of back pain, loss of appetite, and weight loss; her diagnosis was a mass in the pancreatic tail. A distal pancreatectomy combined with lymph node dissection was performed. The tumor measured 10.0 x 9.5 x 8.0 cm and consisted of a cystic mass and a solid area. Histologically, the cystic mass represented a typical mucinous cystadenocarcinoma, whereas the solid portion was composed of anaplastic tumor cells with round eosinophilic intracytoplasmic inclusions, as seen in malignant rhabdoid tumor of the kidney. The hyaline-like intracytoplasmic inclusions were weakly positive for periodic acid-Schiff and were resistant to diastase. There was a gradual transition between the mucinous cystadenocarcinoma and the anaplastic carcinoma showing rhabdoid features. Additionally, the tumor cells of the anaplastic carcinoma were immunoreactive to both epithelial membrane antigen and vimentin. These findings suggest that the anaplastic carcinoma with rhabdoid features developed from the mucinous cystadenocarcinoma of the pancreas.