Matrical carcinoma with melanocytic hyperplasia mimicking nodular melanoma in an elderly Mexican male

Abstract

Matrical carcinoma with melanocytic hyperplasia (MCMH), previously referred to as malignant melanocytic matricoma, is a rare variant of the uncommon pilomatrical carcinoma, occurring most often on the head/neck and upper backs of middle-aged men. Nodular lesions may resemble pigmented basal cell carcinoma or melanoma clinically. We present a case of MCMH in a Hispanic patient with history of melanoma. Histopathological clues to appropriate diagnosis include basaloid cells, numerous atypical mitotic figures, matrical differentiation, shadow cells, strong diffuse nuclear and cytoplasmic expression of ß-catenin, and interspersed pigmented dendritic melanocytes.

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

“…To our knowledge, to date, only 11 cases have been reported in the literature, according to our research using PubMed/Medline, Scopus, and Web of Science databases, with the search terms "malignant melanocytic matricoma" and "matrical carcinoma" [1,[3][4][5][6][7][8][9][10]. The epidemiological, clinical, histopathological, immunohistochemical, and behavioral features of the reported cases of MMM are detailed in Table 1.…”

“…Based on the clinical appearance of this lesion, as it is described since 2003, which appears as a pigmented nodule, occurring on sun-damaged skin, preferentially in the head and neck region (7/11 cases), in the elderly (mean age: 78 years, range: 48-92 years) with a size ranging from 5 mm to 40 mm, the clinical diagnosis is often missed suggesting melanoma, pigmented basal cell carcinoma, seborrheic keratosis, or squamous cell carcinoma (see Table 1) [1,[3][4][5][6][7][8][9][10].…”

Histopathologic features and immunohistochemistry findings to assist the dermatopathologist in differentiating melanocytic matrical carcinoma from melanoma

“…Proposed mechanisms have included paracrine signaling from malignant keratinocytes and release of chemokines from the neoplasm. 2,3,6 Findings that distinguish MMC from melanoma are of particular interest, in light of the drastically different prognosis and treatment of these two conditions. Melanoma typically has markedly pleomorphic melanocytes; on the other hand MMC contains numerous densely pigmented but not atypical melanocytes.…”

“…Matrical neoplasms, a subtype demonstrating hair bulb differentiation, include benign tumors such as matricoma and pilomatricoma and low‐grade malignant neoplasms such as matrical carcinoma 1 . Melanocytic matrical carcinoma (MMC) is an extremely rare subtype of matrical carcinoma, with fewer than 15 reported cases in the literature 2–4 . MMC, also known as matrical carcinoma with melanocytic hyperplasia or malignant melanocytic matricoma, typically presents as a facial nodule in elderly males 3 …”

“…1 Melanocytic matrical carcinoma (MMC) is an extremely rare subtype of matrical carcinoma, with fewer than 15 reported cases in the literature. [2][3][4] MMC, also known as matrical carcinoma with melanocytic hyperplasia or malignant melanocytic matricoma, typically presents as a facial nodule in elderly males. 3 Herein, we present a case of MMC that was initially diagnosed as a metastatic melanoma and report novel histopathologic features.…”