Dermoid cyst (mature cystic teratoma) of the cecum. Histologic and cytologic features with review of the literature.

The gastrointestinal tract is an unusual site for teratomas to occur. Only 4 prior cases of teratomas involving the cecum have appeared in the English literature, the latest published in 1977. To the best of our knowledge, this is the first report to describe fine-needle aspiration cytologic findings in addition to histologic features of a mature cystic teratoma involving the gastrointestinal tract. A 30-year-old man presented with right upper quadrant abdominal pain and a palpable abdominal mass. Radiographic studies identified a mass lesion inferior to the liver and in close association with the ascending colon. Fine-needle aspiration biopsy showed scant keratinous material and anucleated squamous cells. Right colectomy revealed a cystic mass in the wall of the cecum that contained keratinous material and was lined by stratified granular squamous epithelium with sebaceous glands. Clinical and pathologic features with review of the literature are presented, and the differential diagnosis for pericolic cystic masses is discussed in detail.