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Mesenchymal tumors may display morphologic and immunohistochemical overlap with melanocytic tumors, presenting a pitfall for misdiagnosis. We report a 62‐year‐old woman who presented with a recurrent dermal and subcutaneous tumor over the Achilles tendon 15 years following complete excision. Both the primary and the recurrent tumors were characterized by nests and sheets of epithelioid and spindle cells with eosinophilic cytoplasm and uniform ovoid nuclei. The tumor was positive for S100, SOX10, HMB45, cathepsin K, and p63 (weak), while negative for Melan‐A, MiTF, smooth muscle actin, and desmin. Gene fusion analysis of the recurrent tumor revealed a NONO::TFE3 fusion which has been recently reported in two similar cutaneous cases. Our case highlights the potential of a NONO::TFE3 cutaneous epithelioid and spindle cell tumor to recur after a prolonged disease‐free interval without evidence of high‐grade transformation or distant metastasis. Our findings support its classification as a cutaneous mesenchymal neoplasm of intermediate malignancy. [ABSTRACT FROM AUTHOR]

Follicle center lymphomas, including primary cutaneous follicle center lymphoma (PCFCL), may rarely show plasmacytic differentiation. Such cases can pose a diagnostic challenge and can be mistaken for other lymphomas that more commonly include plasma cells. Here, we report four cases of PCFCL and one case of systemic follicular lymphoma involving the skin with associated monotypic plasma cells, including the clinical, morphologic and immunophenotypic features. [ABSTRACT FROM AUTHOR]