PANCREATIC MUCINOUS CYSTIC NEOPLASM WITH SARCOMATOUS STROMA - A REPORT ON 3 CASES

The patients with pancreatic mucinous cystic neoplasms having a sarcom atous stroma are reported. The tumors occurred in two women and one ma n, aged 48, 66, and 67 years, respec lively. Symptoms included epigast ric pain or a palpable abdominal mass or both. Radiographically, all t he tumors were large, multicystic, and located in the tail of the panc reas. Histologically, the cystic component was lined by mucin-producin g, columnar to cuboidal epithelium composed of benign to atypical to o vertly malignant cells (cystadenocarcinoma). Immunohistochemistry show ed the epithelial component of all three tumors to be positive with cy tokeratin, epithelial membrane antigen, carcinoembryonic antigen, and the pancreatic epithelial mucin antibodies CA 19-9 and DUPAN 2. In all three cases, an undifferentiated malignant spindle cell (sar comatous ) stroma was intimately associated with the epithelial component. The sarcomatous component showed variable reac tivity with vimentin (all t hree cases), muscle-specific and smooth-muscle actin (all three cases) , S-100 protein (1/3), Leu-7 (one case), and estrogen and progesterone receptors (in two cases). Two patients died with widespread abdominal disease within 15 months of diagnosis, one of whom had an omen tal me tastasis entirely composed of the sarcomatous stroma. The third patien t was alive and free of disease at 16 months after diagnosis. Our find ings document the existence of a sar comatous component in pancreatic mucinous cystic neoplasms; this component appears to be responsible fo r the highly malignant behavior of the tumors.