Answer: Anaplastic carcinoma

Histology: This is a very unusual case. The esophagus contained a well defined adenocarcinoma, composed of intestinal type glands with luminal necrosis and cribriform architecture. This tumor presented at high stage with nodal metastases. A discrete nodule as illustrated in the figures, was identified containing large pleomorphic tumor cells in a background of dense, chronic inflammation. Taken alone, this focus would raise the differential diagnosis of malignant lymphoma, including Hodgkins disease, and other anaplastic malignancies. However, this focus intermingles with the moderately differentiated adenocarcinoma, providing an H&E clue that it is in fact an anaplastic carcinoma. This diagnosis was confirmed by immunostain for cytokeratin, which highlights the pleomorphic tumor cells within the focus.

Discussion: All the other entities listed in the differential are valid on the basis of the H&E stain. The histologic clue is the presence of a better differentiated adenocarcinoma within the tumor. The diagnosis is proven by immunohistochemistry for cytokeratin.

Tumors often demonstrate an increased inflammatory infiltrate as their cytology progresses toward anaplasia. This is well documented in well differentiated liposarcoma, but seems to be a common theme across many neoplasms.