Malignant Melanocytic Matricoma: A Rare Skin Tumor That Can Clinically Mimic Melanoma

Layla Tahiri Elousrouti; Imane Fadlallah; Meryem Soughi; Houda Elabbad; Hanane Baybay; Fatima Zahra Mernissi; Hinde Elfatemi; Laila Chbani; Nawal Hammas

doi:10.7759/cureus.34105

Malignant Melanocytic Matricoma: A Rare Skin Tumor That Can Clinically Mimic Melanoma

Cureus. 2023 Jan 23;15(1):e34105. doi: 10.7759/cureus.34105. eCollection 2023 Jan.

Authors

Layla Tahiri Elousrouti¹, Imane Fadlallah², Meryem Soughi³, Houda Elabbad³, Hanane Baybay³, Fatima Zahra Mernissi³, Hinde Elfatemi¹, Laila Chbani¹, Nawal Hammas¹

Affiliations

¹ Department of Pathology, Hassan II University Hospital, Sidi Mohamed Ben Abdellah University, Biomedical and Translational Research Laboratory, Faculty of Medicine and Pharmacy, Fez, MAR.
² Department of Pathology, Hassan II University Hospital, Sidi Mohamed Ben Abdellah University, Faculty of Medicine and Pharmacy, Fez, MAR.
³ Department of Dermatology, Hassan II University Hospital, Sidi Mohamed Ben Abdellah University, Faculty of Medicine and Pharmacy, Fez, MAR.

Abstract

Malignant melanocytic matricoma (MMM) is an extremely rare skin malignant neoplasm composed of epithelial cells with matrical differentiation and dendritic melanocytes. We found only 11 cases reported in the literature to date according to the databases consulted (PubMed/Medline, Scopus, and Web of Science). Here, we report a case of MMM in an 86-year-old woman. A histological examination showed a dermal tumor with a deep infiltrative pattern, without an epidermal connection. On immunohistochemical staining, tumor cells were positive for cytokeratin AE1/AE3, p63, and beta-catenin (nuclear and cytoplasmic staining) and negative for HMB45, Melan-A, S-100 protein, and androgen receptor. Melanic antibodies highlighted scattered dendritic melanocytes in tumor sheets. The findings did not support the diagnosis of melanoma, poorly differentiated sebaceous carcinoma, and basal cell carcinoma, but supported the diagnosis of MMM.

Keywords: beta-catenin antibody; carcinoma; dendritic melanocyte; malignant matricoma; matrical differentiation; skin appendage tumor.

Publication types

Case Reports