ABSTRACT Epithelioid vascular tumors range from benign to malignant, including epithelioid hemangioma, cutaneous epithelioid angiomatous nodule, epithelioid hemangioendothelioma, and epithelioid angiosarcoma. Vascular tumors with epithelioid morphology and TPM3/4::ALK fusions have recently been added to this list, in a cohort of five cases. Herein, we report the sixth case (second case with TPM4::ALK specifically). Consistent with the previous report, the current case occurred in a young boy (lateral upper back, 11 years old) and demonstrated a circumscribed tumor with an epidermal collarette, peripheral ectatic thin vessels, and variably solid to vasoformative epithelioid cells with small, somewhat crescent‐shaped vascular channels. CD34, ERG, and ALK immunohistochemical stains were positive and further highlighted vascular structures. RNA sequencing revealed an in‐frame fusion between TPM4 Exon 8 and ALK Exon 20. Conservative excision was performed and recurrence has not been observed at one‐year follow‐up.
Wang et al. (Mon,) studied this question.