Collision of desmoplastic‐neurotropic melanoma and squamous cell carcinoma on the lip

Abstract

We report on a case of the collision of a desmoplastic-neurotropic melanoma and a squamous cell carcinoma on the lip. A 46-year-old male developed a multifocal infiltrative squamous cell carcinoma of the lower lip, which also showed sparse melanocyte atypia within the epidermis and an extensive spindle cell proliferation within the dermis, subcutaneous tissues and nerves. An immunohistochemical panel showed that the spindle cells were melanocytes, not derived from the squamous cell carcinoma. Double labeling with AE1/AE3 and S100 showed striking localized proximity of the spindle-cell melanocytic and keratinocyte components in some areas of this tumor. To our knowledge, this is the first report of the collision of a squamous cell carcinoma and desmoplastic-neurotropic melanoma.

A Rare Case of a Cutaneous Squamomelanocytic Tumor: Revisiting the Histogenesis of Combined Neoplasms

“…3,4,12,13 However, cases of combined tumors in which the 2 cell populations are intimately admixed, particularly within SMTs, are extremely rare. 8 As previously suggested, such cases should always be differentiated from a simple colonization of the SCC by atypical melanocytes.…”

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

“…11 Five cases with a median Breslow depth of 4.2 mm (range, 1.4-6 mm) have had local tumor recurrence and/or regional metastases. 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.…”

Cutaneous neoplasms composed of melanoma and carcinoma: A rare but important diagnostic pitfall and review of the literature

“…Combined tumors are defined as neoplasms composed of two phenotypically distinct yet intermingled cell populations, for which the use of immunohistochemical studies is usually required to highlight the two distinct cell populations . Overlap between these tumors may occur in which tumors show a mixed pattern that can fall into both collision and combined categories . Colonized tumors develop when one type of tumor cell population permeates but remains within a second tumor .…”