Hasegawa S L, Davison J M, Rutten A, Fletcher J A, Fletcher C D
Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Am J Surg Pathol. 1998 Mar;22(3):310-8. doi: 10.1097/00000478-199803000-00005.
Cutaneous small blue cell tumors are relatively uncommon and include primary lesions of either adnexal or neuroendocrine differentiation, as well as metastatic disease. Extraosseous Ewing's sarcoma/malignant primitive neuroectodermal tumor (MPNET) rarely may occur as a primary, superficially based neoplasm in children and young adults. We describe a series of five cases of Ewing's sarcoma/malignant primitive neuroectodermal tumor occurring as a primary cutaneous malignancy supported diagnostically both by immunohistochemical stains and fluorescence in situ hybridization (FISH). All five cases occurred as a solitary dermal nodule and were located in the lower extremities (3 cases), the axilla (1 case), and the flank (1 case). Three of the cases were clinically polypoid. Four of the five patients were female, and age at presentation ranged form 8 to 50 years of age (median, 18 years). All five tumors consisted of nodular proliferations of monomorphous, small blue cells with round, vesicular nuclei, and scant to moderate cytoplasm that were uniformly immunoreactive for the CD99 cell surface glycoprotein in a characteristic membranous pattern. Fluorescence in situ hybridization analysis of paraffin-embedded tissue revealed that three of four tumors were positive for a chromosomal translocation involving the EWS locus at 22q12, seen in more than 90% of cases of Ewing's sarcoma/malignant primitive neuroectodermal tumor. One case was not analyzable. All five patients were treated using local excision, and two patients additionally received postoperative chemotherapy and radiotherapy. Clinical follow-up is available in three cases (median duration, 33 months) and to date none has shown evidence of either local recurrence or metastasis. Because similar cases reported in the literature have likewise had favorable clinical courses after excision, primary cutaneous Ewing's sarcoma/malignant primitive neuroectodermal tumor may represent a clinically favorable subset of this otherwise highly aggressive neoplasm.
皮肤小蓝细胞肿瘤相对少见，包括具有附属器或神经内分泌分化的原发性病变以及转移性疾病。骨外尤因肉瘤/恶性原始神经外胚层肿瘤（MPNET）很少作为儿童和年轻人的原发性浅表肿瘤出现。我们描述了一系列5例尤因肉瘤/恶性原始神经外胚层肿瘤作为原发性皮肤恶性肿瘤的病例，通过免疫组织化学染色和荧光原位杂交（FISH）在诊断上得到支持。所有5例均表现为孤立性真皮结节，位于下肢（3例）、腋窝（1例）和侧腹（1例）。其中3例临床上呈息肉状。5例患者中有4例为女性，就诊时年龄为8至50岁（中位数为18岁）。所有5个肿瘤均由单形性小蓝细胞的结节状增生组成，细胞核圆形、泡状，胞质稀少至中等，对CD99细胞表面糖蛋白呈特征性膜状模式的均匀免疫反应。石蜡包埋组织的荧光原位杂交分析显示，4个肿瘤中有3个对涉及22q12处EWS基因座的染色体易位呈阳性，在90%以上的尤因肉瘤/恶性原始神经外胚层肿瘤病例中可见。1例无法分析。所有5例患者均采用局部切除治疗，2例患者术后还接受了化疗和放疗。3例有临床随访（中位持续时间为33个月），迄今为止，无一例显示局部复发或转移的证据。由于文献报道的类似病例在切除后同样具有良好的临床病程，原发性皮肤尤因肉瘤/恶性原始神经外胚层肿瘤可能代表了这种原本具有高度侵袭性肿瘤的一个临床预后良好的亚组。
