Got Path? Pathology Inc. Consensus Conference 05.31.2006

Figure 1-Melanoma cells exhibited a peculiar growth pattern reminiscent of pemphigus vegetans.

Figure 2-S100 and Mart-1 strongly decorated the melanoma cells.

Figure 3-Cytokeratin staining negative within the melanoma cells.

Figure 1-Melanoma cells exhibited a peculiar growth pattern reminiscent of pemphigus vegetans. Figure 2-S100 and Mart-1 strongly decorated the melanoma cells. Figure 3-Cytokeratin staining negative within the melanoma cells.	Pathology Inc. Consensus Conference May 31, 2006
	Fascinoma of the Day The melanoma in figures 1-3 exhibit a rare and possibly new variant of a malignant melanoma. It is striking for the pemphigus vegetans or acantholytic-like changes it exhibits, replacing much of the epidermis. A CK and Mart-1/S100 confirmed that these cells are indeed melanoma cells and not keratinocytes. In a personal communication with Dr. Cynthia Magro, Chief of Dermatopathology at Cornell University (Beginning July 2006), she agreed with my diagnosis stating that she had never seen a case. She hypothesized that this melanoma may represent a peculiar localized paraneoplastic form of pemphigus in a zone of neoplasia. We are currently performing additional studies and will present this case in a future publication as a new histopathological variant of malignant melanoma! When I was a fellow at Barnes Hospital, working with Dr. Louis Dehner, he once remarked to me that he had seen malignant melanoma grow within the epidermis in a pemphigus-like fashion. I intend to email the case to him and seek his opinion and perhaps gather additional cases. More to come! Diagnostic Nuances We discussed the fine points of diagnostic discernment between a partial mole and hydropic changes in abortions. In addition to the usual histopathological parameters (eg mixture of normal and hydropic villi, trophoblastic hyperplasia, villous scalloping, trophoblastic cytologic atypia), we noted the following could also be taken to aid in the diagnosis: Submit the entire specimen Query the submitting physician about the patient's serum beta hcg levels Consider ploidy analysis by flow cytometry Consider immunoperoxidase studies with p63 Journal Articles Reviewed: Interobserver and intraobserver variability in the diagnosis of hydatidiform mole Fukunaga M, etal. Department of Pathology, Jikei University, Tokyo, Japan. Am J Surg Pathol 2005 Jul;29(7):942-7. P63 expression in hydropic abortion and gestational trophoblastic diseases. Ramalho LN, Maggiori MS, Ribeiro-Silva A, Peres LC. Departamento de Patologia, Faculdade de Medicina de Ribeirao Preto, Avenida Bandeirantes 3900, Campus Universitario Monte Alegre, 14049-900, Ribeirao Preto, Sao Paulo, Brazil.Placenta. 2006 Jun-Jul;27(6-7):740-3. Epub 2005 Jul 18.

	Links
	The Doctor's Doctor-Malignant Melanoma Histopathological Variants The Doctor's Doctor-Gestational Trophoblastic Disease