Spindle-cell (Sarcomatoid) Variant of Cutaneous Anaplastic Large-cell Lymphoma (C-ALCL)

Abstract

Cutaneous anaplastic large-cell lymphoma (C-ALCL) represents one of the entities within the group of CD30-positive lymphoproliferative disorders of the skin. Most cases are ALK-negative, though isolated cases of ALK-positive C-ALCL have also been reported. By definition, the diagnosis of C-ALCL requires the expression of CD30 in >75% of the cells. Histopathologically, C-ALCL shows a dermal-based nodular and circumscribed proliferation of large pleomorphic cells with vesicular nuclei, prominent nucleoli, and eosinophilic cytoplasm, including hallmark cells. Since 1990, isolated case reports of a so-called “sarcomatoid” variant have been published in the literature. Herein, we present a series of 11 cases of spindle (sarcomatoid) C-ALCL, with comprehensive histopathologic, immunophenotypic, and molecular data. Spindle C-ALCL represents a potential mimicker of malignant mesenchymal or hematopoietic tumors in the skin and should always be considered in the differential diagnosis when assessing cutaneous pleomorphic spindle cell neoplasms.

Primary Cutaneous Anaplastic Large-Cell Lymphoma With Aberrant CD20 Expression: Case Report and Review of the Literature

“…Several histopathologic variants of pcALCL have been reported including variants with neutrophilic (pyogenic), small-cell morphology, and even sarcomatoid cells. 33 Neoplastic cells in classic cases of pcALCL express CD2, CD4, CD5, and CD30 (>75% of the cells), as seen in our patient. Similar to our case, these cells are also typically negative for CD8 and CD56.…”