Preferential localization of c-kit product in tissue mast cells, basal cells of skin, epithelial cells of breast, small cell lung carcinoma and seminoma/dysgerminoma in human: immunohistochemical study on formalin-fixed, paraffin-embedded tissues

Abstract

Eighteen hundred and eighty-four cases of human solid tumours and 833 samples of normal human tissues, formalin-fixed and paraffin-embedded, were examined immunohistochemically for expression of c-kit oncogene product using polyclonal antibody against synthesized c-kit peptide. Seminoma/dysgerminoma and small cell lung carcinoma (SCLC) show preferential c-kit expression at 92% and 36% frequency, respectively, whereas only sporadic cases of cervical carcinoma and non-SCLC lung carcinoma show c-kit positivity. A normal tissue counterpart positive for c-kit product is detected in the testis (spermatocyte) and ovary (oocyte) but not in the lung or the cervix. In contrast, normal epithelial cells of the breast, skin basal cells and tissue mast cells harbour c-kit product, but transformed cells of the former two are largely deficient in the c-kit protein. One hundred and thirty-nine neuroendocrine tumours and 39 non-pulmonary small cell carcinomas were all negative, except for two cases of neuroblastoma. This indicates a distinct character for SCLC in c-kit expression. The c-kit product may be a useful marker in diagnostic pathology of seminoma/dysgerminoma and SCLC among human solid tumours, and in distinction of SCLC from non-pulmonary small cell carcinoma.

Immunohistochemical Spectrum of GISTs at Different Sites and Their Differential Diagnosis with a Reference to CD117 (KIT)

“…Malignant melanoma may involve the stomach and especially small intestine, and occasionally such metastases may include GIST as a differential diagnostic consideration, although melanomas usually have patient history of the primary tumor. Like normal melanocytes, melanomas are often CD117 positive (31), and this study showed a surprisingly high frequency of CD117 positivity (73%) among intestinal metastases of melanomas. Although melanocytes and primary melanomas are typically CD117 positive, it has been specifically shown that metastatic melanomas commonly have lessened CD117 expression, suggesting that this marker is lost in melanoma progression (32).…”

The presence of stromal mast cells identifies a subset of invasive breast cancers with a favorable prognosis

“…18 The role of c-kit (CD-117) in breast carcinoma is poorly understood. Some studies have shown that ckit protein is present in normal breast tissue but is absent in female, but not male, breast carcinoma, 19,20 and loss of c-kit expression has been postulated as having a role in the development of breast carcinoma. 21,22 In contrast, Palmu et al 23 found that a high percentage of poor-prognosis breast cancers stain for CD-117 by immunohistochemistry.…”

D2-40 immunohistochemistry in the differential diagnosis of seminoma and embryonal carcinoma: a comparative immunohistochemical study with KIT (CD117) and CD30

“…[7][8][9][10][11] Previous immunohistochemical studies have demonstrated KIT expression in up to 100% of cases of seminoma. [9][10][11] In the present study, 92% of seminomas were positive for KIT, while none of the embryonal carcinomas or other histologic types of non seminomatous germ cell tumors were noted to express this marker, in keeping with the findings of previous investigators.…”

“…CD30 is expressed by the majority of embryonal carcinomas and is generally negative in seminomas, [4][5][6][7] while KIT is regularly expressed in seminomas and only rarely positive in embryonal carcinomas. 7,[8][9][10][11] However, CD30 immunoreactivity has been observed in a number of pure seminomas and seminomatous components of mixed germ cell tumors, 2,7,[12][13][14] and KIT positivity in seminomas has been noted to be variable and weak, 15 somewhat limiting the diagnostic utility of these particular markers.…”