母细胞性浆细胞样树突细胞肿瘤一例

患者男，51岁，全身皮肤散在暗红色斑丘疹、结节1年余。皮损逐渐增多，初发时无明显不适，逐渐出现触痛。体检：头面、躯干、四肢可见散在分布的暗红色斑丘疹、浸润性斑块、皮下结节，边界尚清，部分有触痛，右腹股沟可触及一樱桃大小淋巴结，余浅表淋巴结未触及。骨髓穿刺结果显示，淋巴系统占32.5%，其中幼稚淋巴细胞占10%，此类细胞大小不等，形态多不规则，细胞质量中等，色蓝，核形不规则，核染色质呈颗粒状。皮损组织病理检查：真皮浅层及脂肪组织大量中等大小异型肿瘤细胞弥漫性浸润，肿瘤细胞染色质细颗粒状，稀疏，核仁不明显，核分裂相易见。免疫组化：CD4、CD56、CD43强阳性；CD68及TdT少量细胞阳性；L26、CD3、CD38、颗粒酶B、MPO均阴性。根据临床资料、实验室检查、皮肤组织病理及免疫组化结果，诊断为母细胞性浆细胞样树突细胞肿瘤。

A case of blastic plasmacytoid dendritic cell neoplasm

A 51-year-old man presented with multiple, disseminated dark erythematous maculopapules and nodules over the body surface for more than 1 year. Initially, the patient presented with dark erythematous macules on the trunk without discomfort. Then, lesions gradually spread over the whole body surface with the development of tenderness. Physical examination revealed multiple disseminated dark erythematous, well-demarcated maculopapules, infiltrative plaques and subcutaneous nodules on the face, neck, trunk, upper and lower limbs. Some lesions were tender on palpation. An enlarged cherry-like lymph node was detected on the right inguina. Bone marrow inspiration showed that lymphocytes amounted to 32.5%, and naive lymphocytes accounted for 10%. These lymphocytes varied in size with irregular shape, moderate amount of basophilic cytoplasm, irregular nuclei and granular chromatin. Histopathological examination revealed diffuse infiltrate of numerous medium-sized atypical blastic cells with irregular nuclei in superficial dermis and subcutaneous fat tissue. The blastic cells showed sparse fine-granular chromatin, obscure nucleoli and obvious karyokinesis. Immunophenotype examination showed that tumor cells were strongly positive for CD4, CD56 and CD43, weakly positive for CD68 and terminal deoxynucleotidyl transferase, but negative for L26, CD3, CD38, granzyme B and myeloperoxidase. The diagnosis of BPDCN is confirmed based on typical clinical features, histopathology and immunohistology findings.