Neurofibroma-Like Spindle Cell Melanoma: CD34 Fingerprint and CGH for DiagnosisYeh, Iwei MD, PhD*,†; Vemula, Swapna S. BA, MS*,†; Mirza, Sonia A. MBBS*,†; McCalmont, Timothy H. MD*,†The American Journal of Dermatopathology: August 2012 - Volume 34 - Issue 6 - p 668–670 doi: 10.1097/DAD.0b013e318244819a Extraordinary Case Report Abstract Author Information Abstract: We present a case that highlights the use of two maneuvers useful in the diagnosis of spindle cell melanoma. A shave biopsy from the cheek of a 58-year-old man demonstrated a thin invasive melanoma of 0.3 mm thickness with a less than 2-mm-wide intra-epidermal component. Below this melanocytic lesion, but not contiguous with it, there was a transected S-100-positive and Melan-A-negative spindle cell proliferation. Upon re-excision, no residuum of conventional melanoma was identified, but a residual spindle cell neoplasm that was 4 mm in diameter, nodular, well-circumscribed, cytologically bland, and S-100 positive was noted. At our consensus conference, our group favored neurofibroma but agreed that spindle cell melanoma could not be excluded based on histopathologic features alone. To further address the differential diagnosis, we performed CD34 staining that demonstrated lack of a CD34 fingerprint. We also completed array-based comparative genomic hybridization, which demonstrated gain of chromosome 6p, loss of 6p and gain of 7. These two methods of analysis support a diagnosis of spindle cell melanoma. Departments of *Pathology †Dermatology, University of California, San Francisco, San Francisco, CA. Reprints: Iwei Yeh, MD, PhD, Departments of Pathology and Dermatology, 1701 Dimsadero St, Rm 499, University of California, San Francisco, San Francisco, CA 94115 (e-mail: IweiYehiwei.firstname.lastname@example.org). The authors declare no funding or conflicts of interest. © 2012 Lippincott Williams & Wilkins, Inc.