A case of osteoclast-like giant cell tumor of the pancreas with ductal adenocarcinoma: histopathological, immunohistochemical, ultrastructural and molecular biological studies

Abstract

Osteoclast-like giant cell tumor of the pancreas is a very rare neoplasm, of which the histiogenesis remains controversial. A 63-yr-old woman was hospitalized for evaluation of epigastric pain. An abdominal computerized tomography revealed the presence of a large cystic mass, arising from the tail of pancreas. A distal pancreatectomy with splenectomy was performed. Histologically, the tumor was composed of mononuclear stromal cells intermingled with osteclast-like giant cells. In addition, there was a small area of moderately to well differentiated ductal adenocarcinoma. The final pathologic diagnosis was osteoclast-like giant cell tumor of the pancreas with ductal adenocarcinoma. Here, we describe the histopathological, immunohistochemical, ultrastructural and molecular biological findings of this tumor with review of the literature pertaining to this condition.

Fig. 1

(A) An abdominal computerized tomography reveals the presence of a large cystic mass, arising from the tail of pancreas. (B) The resected tumor is a 8×7×6-cm hemorrhagic and cystic mass in the tail of the pancreas.

Fig. 2

Histologically, the tumor is composed of typical ductal adenocarcinoma (closed arrow) and surrounding mononuclear stromal cells (open arrow) intermingled with osteoclast-like giant cells (closed arrow head) and pleomorphic large cells (open arrow head) (H&E ×200).

Fig. 3

Immunohistochemical staining of cytokeratin (A) and CD-68 (B). Cytokeratin (CK) is strongly positive for ductal carcinoma cells, whereas both osteoclast-like giant cells and mononuclear cells are negative for CK. However, osteoclast-like giant cells and mononuclear cells are positive for histiocytic markers, CD-68 (×200).

Fig. 4

Electron microscopically, the nucleus of the mononuclear cell contains prominent nucleoli, with dispersed clumps of heterochromatin. The cytoplasm contained ample mitochondria, and moderate amount of rough endoplasmic reticulum (×4,000).

Fig. 5

Electron microscopically, osteoclast-like giant cell has multiple nuclei with dispersed chromatin and a fine chromatin rim. The cytoplasm is characterized by abundant mitochondria of varying size, free ribosomes, and dilated empty rough endoplasmic reticulum cisternae (×4,000).