Magro Cynthia M, Wang Xuan, Subramaniyam Shivakumar, Darras Natasha, Mathew Susan
Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, New York, NY.
Am J Dermatopathol. 2014 Apr;36(4):303-10. doi: 10.1097/DAD.0b013e31829beaa7.
Diffuse large cell B-cell lymphoma of the skin is most commonly represented by diffuse large cell variants of primary cutaneous follicle center cell lymphoma and the leg-type lymphoma. In a minority of cases, the infiltrates are an expression of stage 4 disease of established extracutaneous B-cell lymphoma. We describe 3 patients with an aggressive form of B-cell lymphoma secondarily involving the skin. Two of the patients were in the ninth decade of life, whereas 1 patient was 34 years of age. In the elderly patients, there was an antecedent and/or concurrent history of follicular lymphoma, whereas in the younger patient, the tumor was a de novo presentation of this aggressive form of lymphoma. The elderly patients succumbed to their disease within less than a year from the time of diagnosis, whereas 1 patient is alive but with persistent and progressive disease despite chemotherapeutic intervention. The infiltrates in all 3 cases were diffuse and composed of large malignant hematopoietic cells that exhibited a round nucleus with a finely dispersed chromatin. Phenotypically, the tumor cells were Bcl-2 and CD10 positive, whereas Bcl-6 and Mum-1 showed variable positivity. One case showed combined Mum-1 positivity along with an acute lymphoblastic lymphoma phenotype, including the absence of CD20 expression. In each case, there was a c-MYC and BCL2/IGH rearrangement diagnostic of double-hit lymphoma. In one case, there was an additional BCL6 rearrangement, defining what is in essence triple-hit lymphoma. In conclusion, double-hit lymphoma is an aggressive form of B-cell neoplasia resistant to standard chemotherapy regimens, which in many but not all cases represents tumor progression in the setting of a lower grade B-cell malignancy.
皮肤弥漫性大细胞B细胞淋巴瘤最常见的表现形式是原发性皮肤滤泡中心细胞淋巴瘤和腿部型淋巴瘤的弥漫性大细胞变体。在少数情况下，浸润是已确诊的皮肤外B细胞淋巴瘤4期疾病的表现。我们描述了3例侵袭性B细胞淋巴瘤继发累及皮肤的患者。其中2例患者为九旬老人，另1例患者34岁。老年患者有滤泡性淋巴瘤的既往史和/或并存病史，而年轻患者的肿瘤是这种侵袭性淋巴瘤的新发表现。老年患者在诊断后不到一年就死于疾病，而1例患者虽接受了化疗干预，但仍存活但疾病持续进展。所有3例患者的浸润均为弥漫性，由大的恶性造血细胞组成，这些细胞呈圆形核，染色质细分散。从表型上看，肿瘤细胞Bcl-2和CD10阳性，而Bcl-6和Mum-1呈可变阳性。1例显示Mum-1阳性合并急性淋巴细胞白血病表型，包括CD20表达缺失。在每例患者中，均有c-MYC和BCL2/IGH重排，诊断为双打击淋巴瘤。1例患者还有额外的BCL6重排，本质上定义为三打击淋巴瘤。总之，双打击淋巴瘤是一种对标准化疗方案耐药的侵袭性B细胞肿瘤，在许多但并非所有病例中，它代表了低级别B细胞恶性肿瘤背景下的肿瘤进展。
