FNAC guided by computed tomography in the diagnosis of primary pancreatic adenosquamous carcinoma. A report of three cases.

Background: Pancreatic adenosquamous carcinoma (ASqC) is an unusual histologic subtype of nonendocrine neoplasia of the pancreas. Although fine needle aspiration cytology (FNAC) is now accepted as a reliable procedure for the diagnosis of pancreatic malignancies, many of these unusual tumors are still diagnosed after surgery or at necropsy.

Cases: Between January 1995 and July 1996, 3 of 35 primary pancreatic malignant tumors were diagnosed as ASqC based on computed tomography-guided FNAC. After cytologic diagnosis, all three patients were treated with neoadjuvant chemotherapy and radiotherapy. Two patients completed the treatment and underwent a surgical pancreatic-duodenectomy with antrectomy. The remaining patient is currently under treatment. That patient had a highly infiltrative pancreatic mass that affected the muscular small bowel wall. An endoscopic biopsy was performed. The cytologic diagnosis was confirmed by histology in all cases. Immunohistochemically both components, squamous and glandular, showed reactivity for several keratins, while only the glandular pattern was reactive with carcinoembryonic antigen (CEA).

Conclusion: FNAC is an accurate, rapid and sensitive tool in the diagnosis of ASqC of the pancreas. We recommend a careful search for both malignant components. Immunoreactivity for CEA can be of help in the detection of the glandular component of this tumor.