Amelanotic Malignant Melanoma With Atypical Divergent Neuroendocrine Differentiation: A Report of an Unusual and Rare Case of Anorectal Bleeding.

Autor:	Mg S; Department of Pathology, Sri Ramaswamy Memorial (SRM) Medical College Hospital and Research Centre, SRM Institute of Science and Technology (SRMIST), Chengalpattu, IND., Cd A; Department of Pathology, Sri Ramaswamy Memorial (SRM) Medical College Hospital and Research Centre, SRM Institute of Science and Technology (SRMIST), Chengalpattu, IND., Verma S; Department of Pathology, Sri Ramaswamy Memorial (SRM) Medical College Hospital and Research Centre, SRM Institute of Science and Technology (SRMIST), Chengalpattu, IND., S N; Department of Pathology, Sri Ramaswamy Memorial (SRM) Medical College Hospital and Research Centre, SRM Institute of Science and Technology (SRMIST), Chengalpattu, IND., John JJ; Department of Pathology, Sri Ramaswamy Memorial (SRM) Medical College Hospital and Research Centre, SRM Institute of Science and Technology (SRMIST), Chengalpattu, IND.
Jazyk:	angličtina
Zdroj:	Cureus [Cureus] 2024 Aug 14; Vol. 16 (8), pp. e66905. Date of Electronic Publication: 2024 Aug 14 (Print Publication: 2024).
DOI:	10.7759/cureus.66905
Abstrakt:	Melanocytes located between the anal transition zone and the dentate line of the anal canal can give rise to the uncommon malignant tumor known as anal melanoma. It has a fast-paced clinical course and can masquerade as several common anorectal symptoms, such as hemorrhoids or rectal ulcers. In melanoma, divergent differentiation is a very uncommon phenomenon. The diagnosis of melanoma is difficult with histopathology sections alone (hematoxylin and eosin, H&E). Special stains and ancillary immunohistochemistry investigations are useful in these situations. A 60-year-old female patient presented to the surgical outpatient department with complaints of anorectal bleeding. After clinical evaluation, a growth in the anorectal region was identified, and a biopsy was taken from the growth. Histopathological and subsequent immunohistochemical analysis of the biopsy material was done at the Department of Pathology. A diagnosis of amelanotic melanoma with atypical and divergent neuroendocrine differentiation involving the anorectal region was rendered. Histologically, this tumor showed extremely pleomorphic polygonal to elongated spindle cells that co-expressed neuroendocrine markers and were positive for S100, HMB-45, and Melan-A. This case presented many diagnostic challenges at both the histomorphological level and the immunohistochemical expression profile analysis. We will go into great depth regarding the diagnostic challenges in this instance and provide an outline of our approach. The immunohistochemical and prognostic importance of this case will also be covered. Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work. (Copyright © 2024, MG et al.)
Databáze:	MEDLINE
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