Chuang Shih-Sung, Hsieh Yen-Chuan, Ye Hongtao, Hwang Wei-Shou
Department of Pathology, Chi-Mei Medical Center, Tainan, Taiwan.
Pathol Res Pract. 2009;205(4):283-7. doi: 10.1016/j.prp.2008.10.009. Epub 2008 Dec 16.
Systemic anaplastic large cell lymphoma (ALCL) involving the skin should be differentiated from primary cutaneous CD30-positive T-cell lymphoproliferative disorders. The lymphohistiocytic variant of ALCL (LH-ALCL) is rich in reactive histiocytes with relatively few neoplastic cells, which pose a diagnostic challenge. We present a case of LH-ALCL involving skin mimicking granulomatous inflammation. A 30-year-old woman presented with cervical lymphadenopathy and multiple non-tender, non-itching, erythematous papules over the neck, chest, and abdomen. Biopsy of the cervical lymph node showed LH-ALCL with null cell phenotype. Microscopically, the cutaneous lesion was located predominately around the hair follicle, with numerous reactive histiocytes and scanty medium-sized lymphoma cells expressing CD30 and anaplastic lymphoma kinase (ALK) protein. Furthermore, an ALK gene rearrangement was demonstrated by locus-specific interphase fluorescent in situ hybridization, confirming cutaneous involvement with LH-ALCL. LH-ALCL involving the skin is a rare event, and the numerous reactive histiocytes may mask scanty tumor cells. In addition to B-and T-cell markers, (dermato) pathologists must be aware of this entity in cutaneous lymphohistiocytic proliferations and perform immunostaining for CD30 and ALK to reach a correct diagnosis.
累及皮肤的系统性间变性大细胞淋巴瘤（ALCL）应与原发性皮肤CD30阳性T细胞淋巴增殖性疾病相鉴别。ALCL的淋巴组织细胞变异型（LH-ALCL）富含反应性组织细胞，肿瘤细胞相对较少，这给诊断带来了挑战。我们报告一例LH-ALCL累及皮肤，表现为肉芽肿性炎症。一名30岁女性，出现颈部淋巴结肿大，颈部、胸部和腹部有多个无压痛、无瘙痒的红斑丘疹。颈部淋巴结活检显示为具有裸细胞表型的LH-ALCL。显微镜下，皮肤病变主要位于毛囊周围，有大量反应性组织细胞和少量表达CD30和间变性淋巴瘤激酶（ALK）蛋白的中等大小淋巴瘤细胞。此外，通过位点特异性间期荧光原位杂交证实了ALK基因重排，确诊为LH-ALCL累及皮肤。LH-ALCL累及皮肤是一种罕见情况，大量反应性组织细胞可能掩盖少量肿瘤细胞。除了B细胞和T细胞标志物外，（皮肤）病理学家在皮肤淋巴组织细胞增殖中必须了解这一实体，并进行CD30和ALK免疫染色以做出正确诊断。
