Sur-2. Undifferentiated (anaplastic) carcinoma of the pancreas with osteoclast-like giant cells: a report of long-term survival.

Undifferentiated (anaplastic) carcinomas with osteoclast-like giant cells are very unusual neoplasms with controversial histiocytic origin. In the pancreas, they represent less than 1% of non-endocrine malignancies and are believed to have a uniformly poor prognosis. We present a case of long-term (6-year) survival in a patient with such a neoplasm. A 73-year-old female was noted to have a mass in the left upper quadrant on physical exam. The patient was entirely asymptomatic. A CT scan of the abdomen revealed a large complex mass in the tail of the pancreas. At laparotomy, no evidence of metastatic disease was noted, and distal pancreatectomy was carried out with clear margins. The pathology specimen contained a 14.5 X 10.0 X 11.0-cm well-encapsulated multicystic mass with three distinctly different histologies. These included areas of ductal adenocarcinoma, spindle cell formation, and osteoclast-like giant cells. Immunohistochemistry demonstrated positivity for cytokeratin AE1/AE3 only in the conventional adenocarcinoma component. Vimentin stains were positive only in the spindle cells and osteoclast-like giant cells. CD-68 stains were positive only in the osteoclast-like giant cells. Six years post resection the patient remains free of disease both clinically and radiographically. Multinucleated giant cells similar to osteoclasts are seen in a variety of neoplasms, including those found on rare occasion in the pancreas. The histogenesis of these tumors is controversial. The osteoclast-like giant cells in this case stained positive for CD-68, and we believe our results favor a histiocytic origin for these cells. Additionally, our patient survived 6 years after operative therapy. Previous case reports indicate a much shorter life expectancy in patients with these tumors.

Grettel K. Wentling, MD, and Stephen L. Smith, MD. Mayo Clinic Jacksonville, FL.