At necropsy of a five-year-old sheep, a pear shaped, lobular yellow-brownish mass measuring about 12 ×15 × 20 cm was found to involve the right hepatic lobe. Microscopic examination revealed two trabecularand solid patterns of neoplastic hepatocytes. In solid pattern, there were numerous tumoral giant cells thatcontain one or more large hyperchromatic bizarre-shaped nuclei scattered among clust...

BACKGROUND Malignant liver tumors with osteoclast-like giant cells are rare. A literature search showed 17 previously reported cases that included the following: (1) 8 undifferentiated hepatocellular carcinomas, (2) 5 sarcomatous tumors with osteoclast-like giant cells associated with intrahepatic cholangiocarcinoma or liver cystadenocarcinoma, and (3) 4 sarcomatoid tumors with osteoclast-like ...

The sequential transformation of chicken monocytes into macrophages, epithelioid cells, and multinucleated giant cells in vitro was studied by electron microscopy after fixation and embedment in situ. The following changes occur. In the nucleus, margination of chromatin, evident in monocytes, decreases in later forms. Nucleoli become more complex and nuclear pores increase in number. In cytopla...

Bone resorption requires cooperation between osteoclasts and mononuclear accessory cells by mechanisms which have not been elucidated. Since multinucleated cells in giant cell tumors of bone have many phenotypic and functional characteristics of normal osteoclasts, we have examined the interaction between the bone-resorbing multinucleated cells and the distinct mononuclear stromal cells from th...

In this article we present a 53-year-old lady, who had progressive indurated skin lesions on her both forearms since 3 months ago, without skin discoloration. Chest x-ray showed parahilar lymphadenopathy, in high resolution CT (HRCT) scan evaluation multiple lymph nodes in upper and middle mediastinum were reported. Angiotensin converting enzyme (ACE) level was increased to 81 (normal 5-5...

Giant cell tumor of soft tissue is a rare tumor first described by Salm and Sissons in 1972 as being a distinct entity.(1) Histologically, it is composed of multinucleated giant cells dispersed among mononuclear cells, and is indistinguishable from its bone equivalent.(2) The majority of these tumors have been reported to occur in the lower extremity.(2,3) We describe a case of giant cell tumor...

TNFα is one of the inflammatory cytokines which plays an important role in activating the Caspase and inducing the apoptosis. This cytokine which is secreted in inflammations, induces the NO production in macrophages and leads to differentiation of the macrophages to the epithelioid and giant cells. One of the most important factors which stimulates the TNFα secretion, is LPS and th...

Multinucleate giant cells of one type or another are commonly encountered in oral and maxillofacial lesions. These include the common occurrence of foreign-body-type giant cells in some reactive lesions, and giant cells associated with granulomatous inflammation as a consequence of infection. However in these cases the giant cells do not represent the primary pathology. In this brief review, we...

A rare case of pleomorphic giant cell carcinoma of the stomach in a 70-year-old man is reported. Characteristic microscopic findings included a general lack of architectural cohesiveness, aggregates of mononucleated or multinucleated giant cells, extensive areas of coagulative necrosis, and numerous mitoses. Immunohistochemically, tumor cells displayed cytoplasmic immunoreactivity for cytokerat...

Giant granules ( 1 sm in diameter), Auer rods, and unique giant granules that contained crystalloid material were investigated in monoblasts from a patient with acute monocytic leukemia using ultrastructural and cytochemical techniques. The latter granule type differed from abnormal granules previously described in leukocytes. In Wright’s stained preparations, these granules appeared to be crys...