Mast Cell Tumors and Histiocytomas in Domestic Goats and Diagnostic Utility of CD117/c-Kit and Iba1 Immunohistochemistry

Abstract

Cutaneous round cell tumors in goats present a diagnostic challenge. In this article, we provide a description of caprine cutaneous mast cell tumors (MCT) and histiocytomas, and report on the validation of anti-human antibodies to CD117/KIT and Iba1 by immunohistochemistry on a range of caprine tissues. Cells immunolabeled for CD117/KIT included resident mast cells in normal lung and skin, interstitial cells of Cajal (intestine), and neuronal cell bodies (brain). Cells immunolabeled for Iba1 included resident macrophages in many tissues including normal lung, dendritic cells (hemolymphatic tissues), Kupffer cells, and microglia. Of 5 cutaneous MCT, only one had metachromasia of cytoplasmic granules; however, neoplastic cells of all 5 MCT had positive immunolabeling for CD117/KIT. The CD117/KIT immunolabeling pattern was predominately focal paranuclear in 3 cases, and cytoplasmic or membranous in 1 case each. Two histiocytomas were identified and had strong positive immunolabeling for Iba1 but not CD117/KIT. All 7 cutaneous round cell tumors described herein occurred in goats less than 4 years of age; the 2 cutaneous histiocytomas were in goats less than 14 months of age. Neither of the cutaneous histiocytomas recurred within 24 months of surgical removal.

Smoking enhanced the expression of c-kit in chromophobe renal cell carcinoma

“…Many studies have shown that c-kit plays a very important role in the occurrence and development of different cancers 7 . The overexpression of c-kit can promote the occurrence and development of KIT-dependent cell types of tumors, such as gastrointestinal stromal tumors, mast cell tumors, and germ cell tumors 8 . For gastrointestinal stromal tumors, leukemias and other tumors with abnormally high expression of c-kit, drugs that downregulate the expression of c-kit have already been available and have good clinical effects.…”