Primary invasive melanoma and basal cell carcinoma (collision tumor) with blue nevus‐like cutaneous metastases

Abstract

The simultaneous presence of two disparate neoplasms occurring in the same specimen has been well documented, albeit uncommonly. The juxtaposition of malignant melanoma and basal cell carcinoma (BCC) has been rarely reported in case reports, with most cases describing melanoma in situ and BCC. We present two cases of invasive melanoma (Clark level IV, no microscopic satellites present) intimately associated with BCC, and in areas distinction of the two lesions was difficult. Immunohistochemical studies delineated the two cell populations. In addition, one patient presented with multiple cutaneous metastases, all simulating blue nevi. The metastases occurred in the same anatomical region as the primary tumor, and histologically consisted of pigmented dendritic melanocytes and melanophages in the superficial and mid-dermis and arranged in a blue nevus-like lesion. Histologic clues suggesting the possibility of a metastatic melanoma included a sparse lymphocytic infiltrate, the presence of an epithelioid component and atypia of the dendritic melanocytes. However, without appropriate clinical history, the lesions could be overlooked as ordinary blue nevus. Collision tumors containing invasive melanoma and BCC are rare and this is the first report of a collision tumor with blue nevus-like metastasis. Awareness of this phenomenon and pattern of metastasis, together with the clinical findings will aid in the correct classification of these lesions.

Collision Tumour of Squamous Cell Carcinoma and Malignant Melanoma in the Oral Cavity of a Dog

“…In man, basal cell carcinoma and melanocytic nevus and, much less frequently, MM and basal cell carcinoma or SCC, have been described in the skin (King et al, 2007). Anatomical location and gross appearance of the tumours described here closely resembled previous reports (Todoroff and Brodey, 1979;Ramos-Vara et al, 2000;Nemec et al, 2012), in which lesions that tend to ulcerate are often diagnosed as oral SCCs or MMs.…”

“…In human and veterinary pathology, a number of immunohistochemical markers have been described for establishing the biological behaviour of carcinomas and melanocytic neoplasms (Ramos-Vara et al, 2000;Koenig et al, 2002;Raul et al, 2004;S anchez et al, 2007;Dor e, 2011;Newman et al, 2012).…”

Combined cutaneous tumors with a melanoma component: A clinical, histologic, and molecular study

“…11,21,[28][29][30] Two were BMTs, 1 with a Breslow depth of 1.4 mm and metastases to the cervical lymph nodes and the liver, and another with a Breslow depth of 1.6 mm and multiple cutaneous metastases. 11,31 The third patient had a SMT with a Breslow depth of 6 mm that recurred locally. 29 Two additional cases had metastases, both to sentinel lymph nodes: first, a dermal SMT with a Breslow In our study, the median follow-up time was 25 months (Tables I and II).…”

Melanocytic Matricoma With Melanocytic Atypia: Report of a Unique Case and Review of the Literature

“…20,21 These tumors showed similar cellular components to melanocytic matricoma but were classified as carcinoma based upon histopathologic features described in pilomatrix carcinomas such as increased mitoses, severe nuclear pleomorphism, The incidence of atypical or malignant melanocytes within cutaneous epithelial tumors is low, and only a few cases have been reported in SCCs, BCCs, and tumors with adnexal differentiation. [1][2][3][4][5][6][7][8] The incidence of collision tumors, in which a discrete atypical melanocytic proliferation may be seen adjacent to or ''colliding with'' a tumor of alternative differentiation, is more frequently reported in the literature than true biphasic tumors, in which an intimate admixture of atypical melanocytes and other cells exists. Given the close intermingling of the atypical melanocytes with the matrical cells in this case, we believe that the behavior of biphasic tumors is more relevant to our patient.…”

“…Melanocytic colonization and/or differentiation have been reported in squamoproliferative lesions, basal cell carcinomas (BCCs), and adnexal tumors. [1][2][3][4][5][6][7][8][9][10][11] Melanocytic matricoma, a rare entity first described by Carlson et al 12 in 1999, is an additional unique cutaneous tumor with combined melanocytic and nonmelanocytic differentiation. Since the initial reported cases, 8 more cases have been described in the English literature.…”