Service of Dermatology, Complejo Asistencial Universitario de Salamanca, Salamanca, Spain.
Department of Pathology, Complejo Asistencial Universitario de Salamanca, Salamanca, Spain; and.
Am J Dermatopathol. 2020 Dec;42(12):972-976. doi: 10.1097/DAD.0000000000001761.
Atypical fibroxanthoma is a rare mesenchymal skin tumor of intermediate malignancy that typically occurs on sun-damaged skin of elderly patients. Histologically, it is composed of pleomorphic cells with hyperchromatic nuclei and abundant cytoplasm, commonly arranged in a spindle cell pattern. Different histologic variants have been described during the past years. We present a case of atypical fibroxanthoma containing a dense inflammatory infiltrate, which in conjunction with the existence of immunoblast-like and Reed-Sternberg-like neoplastic cells could be misinterpreted as a lymphoid neoplasm. Immunohistochemical studies revealed strong positivity of tumor cells for CD10 and negativity for cytokeratins, p63, p40, S100, SOX10, ERG, actin, desmin, B and T-cell markers, BCL6, CD15, and CD30. The inflammatory infiltrate contained a mixed reactive T- and B-cell population with negative T-cell receptor and immunoglobulin heavy rearrangements. We discuss the differential diagnosis of this entity in which clinical, immunohistochemical, and molecular features are essential to avoid the diagnosis of a lymphoproliferative disease.
非典型纤维黄色瘤是一种罕见的间叶性皮肤肿瘤，具有中等恶性，通常发生在老年患者的日光损伤皮肤上。组织学上，它由具有深染核和丰富细胞质的多形性细胞组成，通常呈梭形细胞模式排列。在过去的几年中，已经描述了不同的组织学变体。我们报告了一例含有密集炎症浸润的非典型纤维黄色瘤，结合存在免疫母细胞样和 Reed-Sternberg 样肿瘤细胞，可能被误诊为淋巴肿瘤。免疫组织化学研究显示肿瘤细胞对 CD10 呈强阳性，对细胞角蛋白、p63、p40、S100、SOX10、ERG、肌动蛋白、结蛋白、B 和 T 细胞标记物、BCL6、CD15 和 CD30 呈阴性。炎症浸润包含混合反应性 T 和 B 细胞群体，T 细胞受体和免疫球蛋白重排呈阴性。我们讨论了该实体的鉴别诊断，其中临床、免疫组织化学和分子特征对于避免诊断为淋巴增生性疾病至关重要。
