Premium
Of all the nerve! A subcutaneous forelimb mass on a cat
Author(s) -
Tremblay Nathalie,
Lanevschi Anne,
Doré Monique,
Lanthier Isabelle,
Desnoyers Michel
Publication year - 2005
Publication title -
veterinary clinical pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 51
eISSN - 1939-165X
pISSN - 0275-6382
DOI - 10.1111/j.1939-165x.2005.tb00073.x
Subject(s) - forelimb , subcutaneous tissue , anatomy , medicine , pathology
Abstract A 16‐year‐old, male, neutered cat had a 2.5 × 1.5 cm mass on the medial aspect of the right carpus. Cytologic examination of a fine‐needle aspirate of the mass indicated a markedly pleomorphic population of plasmacytoid to histiocytic‐appearing cells. The cytologic diagnosis was malignant neoplasia of probable mesenchymal or round cell origin. The right forelimb was surgically removed and the scapular, axillary, and prescapular lymph nodes were excised. Malignant fibrous histiocytoma was tentatively diagnosed histologically; however, the tumor cells subsequently were found to be negative for histiocytic (MAC 387, antitrypsin), T‐cell (CD3), and B‐lymphocyte (immunoglobulin light chains, Ly 5/CD45R) markers, and positive for glial fibrillary acidic protein, vimentin, and S‐100. Based on the immunohistochemical results, the diagnosis was modified to malignant peripheral nerve sheath tumor (PNST). Six months after surgery, the cat was reported to be well and had no evidence of metastasis. PNSTs are rare tumors in cats, and are considered as synonymous with schwannomas, neurofibrosarcomas, and hemangiopericytomas. In this cat, the plasmacytoid and pleomorphic appearance of the PNST cells in cytologic and histologic specimens was unusual, and made it difficult to reach an accurate diagnosis without immunocytochemistry.