Feline uterine carcinosarcoma infiltrated with osteoclast-like giant cells

Abstract

A 12-year-old female Himalayan cat underwent an ovariohysterectomy to remove an intraabdominal mass. Histologic examination using immunohistochemical staining revealed that the mass was comprised of epithelial and mesenchymal components. Within the lesion, multinucleated giant cells (MGCs) were observed diffusely. MGCs were positive for vimentin and Iba-1 and negative for cytokeratin AE1/AE3 and CD204. In addition, MGCs were negative for Ki-67, indicating nonneoplastic cells. Osteoclast-like MGC (OLMGC) phenotype with tartrate-resistant acid phosphatase positivity was also seen. These findings suggested that the uterine tumor was carcinosarcoma with OLMGCs. Uterine tumors in humans, such as leiomyosarcoma and carcinosarcoma, with OLMGC infiltration are well-known pathologic entities; however, they are rare in animals and to our knowledge, have not been previously reported in cats.

Vertebral giant cell tumour of bone in a domestic shorthair cat

“… 18 , 40 , 41 The giant cells in this tumour are labelled with Iba1. Other than Iba1 expression of tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like multinucleated giant cells in a feline uterine carcinosarcoma, 7 Iba1 labelling of osteoclasts is not widely reported. Unfortunately, TRAP was not available in this case.…”

“…Immunohistochemistry with a histiocytic marker (ionised calcium binding adaptor molecule 1 [Iba1]; monoclonal AIF19mouse anti-Iba1 [Merck Millipore]), a general mesenchymal marker (vimentin [monoclonal mouse anti-vimentin, Clone V9; Dako]) and an osteoblast-specific transcription factor marker (osterix [polyclonal rabbit anti-Sp7/osterix; Abcam]) was performed. 2 – 7 The multinucleated giant cells exhibited weak cytoplasmic labelling with Iba1 ( Figure 3d ), suggestive of a monocyte/macrophage lineage. Most of the spindle cells showed nuclear labelling with osterix and both cell populations showed cytoplasmic labelling with vimentin ( Figure 3e , f ).…”