Microphthalmia transcription factor and NKI/C3 expression in cellular neurothekeoma

Abstract

While the usual or myxoid-type neurothekeoma has been reasonably well established as being a tumor of neural origin, the cellular neurothekeoma remains in disputed histogenesis. We studied a series of 11 cellular neurothekeomas using paraffin immunoperoxidase staining with microphthalmia transcription factor (Mitf), NKI/C3, and S-100. The majority of the tumors in our series stained with NKI/C3 (9/11) and Mitf (9/11). All failed to stain with S-100. Furthermore, we divided our series of cellular neurothekeomas according to cytomorphology; tumors demonstrating predominantly spindled morphology, predominantly epithelioid morphology, and mixed spindle and epithelioid morphology. The two tumors that failed to stain with NKI/C3 both demonstrated predominantly spindled morphology. One of the tumors that failed to stain with Mitf showed exclusive spindled morphology, while the other showed mixed morphology (spindle and epithelioid). Two of the tumors, which stained strongly with Mitf, however, showed exclusive epithelioid morphology. This current study furthers the concept that cellular neurothekeoma is a tumor of neuroectodermal origin, and further suggests that it may express some component of melanocytic differentiation.

Apolipoprotein D in CD34-positive and CD34-negative cutaneous neoplasms: a useful marker in differentiating superficial acral fibromyxoma from dermatofibrosarcoma protuberans

“…Our own experience with recently proposed markers of utility for the same such as CD10 and CD99 is that they are inconsistently expressed and also expressed in a number of other lineageunrelated neoplasms. [23][24][25][26] Speculative as it may seem, given that we did not study ApoD expression in other atypical spindled cell neoplasms, the consistently strong positive Apo D staining (3 þ , 80%) in cases of atypical fibroxanthoma suggests that this marker holds some promise in terms of diagnostic utility.…”

Cellular neurothekeoma: analysis of 37 cases emphasizing atypical histologic features

“…2,3,5,23,24 In our series, all of the cases tested were at least focally positive for NKI-C3 and 29/30 (97%) were positive for CD10. This parallels what has been previously reported in the literature.…”

“…Immunoreactivity for MiTF has been seen in 81-100% of cellular neurothekeoma. 23,29 In this series, two of three cases tested were positive for MiTF. Immunostains for CD68 are insufficiently sensitive, as just under half of the cases tested were positive (6/13).…”

Aberrant intermediate filament and synaptophysin expression is a frequent event in malignant melanoma: an immunohistochemical study of 73 cases

“…42,43 More recently developed markers such as MiTF and/or SOX10 may also be of value in selected cases, although these markers lack perfect specificity for melanoma. [44][45][46][47][48] In our experience, two other scenarios where aberrant marker Aberrant marker expression in melanoma expression in melanoma causes difficulty is when the referring pathologist hasn't considered the possibility of melanoma or is simply unaware that this may happen. Failing to include melanoma in the differential diagnosis seems most often to happen for lesions occurring in non-cutaneous locations (especially the sinonasal region and viscera), in the metastatic setting when a prior history of melanoma has not been provided, and in exclusively spindled or round cell (small cell) melanomas.…”