A clinicopathologic and immunohistochemical study of 35 anaplastic carcinomas of the pancreas with a review of the literature.

Anaplastic pancreatic carcinomas are rare tumors, frequently displaying a variety of growth patterns. The literature lacks a comprehensive study of this tumor. Thirty-five cases of anaplastic carcinoma of the pancreas diagnosed between 1955 and 1997 were retrieved from the Endocrine Registry at the Armed Forces Institute of Pathology. Histology, immunophenotype, molecular analysis, and patient follow-up were analyzed. The tumors of 10 women and 25 men, aged 34 to 85 years (mean age at presentation, 62.5 years), were studied. Patients had vague symptoms (weight loss, pain, and fatigue, nausea, or vomiting), lasting an average of 13.2 weeks. The tumors, of an average size of 9.2 cm, were usually in the head or tail of the pancreas. The tumors were widely infiltrative, histomorphologically separated into predominantly large, pleomorphic cell, or spindle cell groups. Tumor phagocytosis and necrosis were noted. Immunohistochemical studies confirmed an epithelial origin with at least one epithelial marker in 78% of the tumors. K-ras mutations by sequence analysis were found in eight of 12 cases tested. Surgical biopsy/excision was used in all patients. Twenty-nine of 35 patients died of disease (average, 5.2 months), three died with no evidence of disease (average, 56.9 months), and three patients were alive at last follow-up (average, 94.0 months), one with residual disease. There was no statistically significant difference in survival between patients with and without a K-ras mutation. Anaplastic carcinoma of the pancreas usually occurs in the head of the pancreas in older men. The epithelial nature of the pleomorphic cells (giant or spindled) can usually be documented. Patients with K-ras mutations have a shorter survival time, even though the overall prognosis for all anaplastic carcinomas is fatal (93% fatality; average survival, 448 days). Ann Diagn Pathol 5: 129-140, 2001. This is a US government work. There are no restriction on its use.