RESUMEN
BACKGROUND/AIMS: T-cell acute lymphoblastic leukemia (T-ALL) is an uncommon, aggressive malignancy that rarely presents in the skin and is generally not considered as part of the differential diagnosis by dermatologists and dermatopathologists. We describe an unusual case of T-ALL presenting with folliculocentric, erythematous papules on the face, histologically resembling mycosis fungoides (MF). Immunostaining for terminal deoxynucleotidyl transferase (TdT) was positive in tumor cells, supporting the diagnosis of cutaneous involvement by T-ALL. TdT is a nuclear enzyme expressed by immature lymphoid malignancies, but the expression pattern of this marker is not well characterized in the skin. We aimed to assess TdT staining in skin biopsies with similar-appearing lymphocytic infiltrates. METHODS: We evaluated the immunostaining profile of TdT in a cohort of 23 patients, including 13 cases of MF and 10 cases of spongiotic dermatitis. RESULTS: The lymphocytes in the MF and spongiotic dermatitis cases lacked nuclear staining for TdT. Nonspecific, granular, cytoplasmic staining was observed in a small number of background cells. CONCLUSIONS: TdT may assist dermatopathologists in discriminating malignant infiltrates of T-ALL from other conditions.
RESUMEN
BACKGROUND: Cutaneous carcinosarcoma is a rare tumor with distinct malignant epithelial and mesenchymal cell populations. The histologic subtypes of epithelial and mesenchymal components in cutaneous carcinosarcoma are variable, as an assortment of carcinomatous and sarcomatous patterns have been described in the literature. METHODS: Clinical information was obtained from patient charts and archival slides were retrieved and reviewed. RESULTS: We present a novel series of six distinct cases of cutaneous carcinosarcoma and review the literature. Our cases consisted of basal cell, pilomatrical, squamous cell, and trichoblastic variants. These cases occurred in elderly men on sun exposed skin with treatment and follow up was available for 4 of 6 cases. The four cases were treated with Mohs micrographic surgery with mean follow up of nine months. CONCLUSION: We report six cases of cutaneous carcinosarcoma with distinctive clinical and histologic characterization not previously described in a single series.