Chiu L L, Koay E S C, Chan N H, Salto-Tellez M
Molecular Diagnosis Centre, Department of Laboratory Medicine, National University Hospital, Singapore.
Diagn Cytopathol. 2003 Dec;29(6):341-3. doi: 10.1002/dc.10397.
Desmoplastic small round cell tumor (DSRCT) is a rare undifferentiated neoplasm. The prognosis is poor, even if therapy is instituted promptly, and thus it is important to differentiate it from other histologically and cytologically similar-looking malignancies of the young adult. We present a case of DSRCT in a 17-yr-old male with disseminated peritoneal disease and peritoneal effusion. The cytology sample showed a malignant small round cell tumor, the classical cytological features of DSRCT, and immunohistochemistry performed in the prepared cell block exhibited an antibody expression profile in keeping with DSRCT. Further material from the effusion was prepared for RNA extraction, following which a reverse-transcriptase polymerase chain reaction (RT-PCR) and sequencing of the t(11;22)(p13;q11 or q12) were carried out. The result showed the presence of the reciprocal translocation and thus confirmed the diagnosis of DSRCT. This case shows how molecular techniques (including sequencing) can be applied to cytology in clarifying and confirming certain difficult diagnosis of undifferentiated neoplasms, DSRCT in this particular case.
促结缔组织增生性小圆细胞肿瘤（DSRCT）是一种罕见的未分化肿瘤。即使及时进行治疗，其预后也很差，因此将其与其他组织学和细胞学上外观相似的青年成人恶性肿瘤进行鉴别很重要。我们报告一例17岁男性DSRCT病例，该患者有弥漫性腹膜疾病和腹腔积液。细胞学样本显示为恶性小圆细胞肿瘤，具有DSRCT的典型细胞学特征，在制备的细胞块中进行的免疫组织化学显示抗体表达谱与DSRCT一致。从积液中获取更多样本用于RNA提取，随后进行逆转录聚合酶链反应（RT-PCR）以及t(11;22)(p13;q11或q12)测序。结果显示存在相互易位，从而确诊为DSRCT。该病例展示了分子技术（包括测序）如何应用于细胞学，以明确和确认某些未分化肿瘤（在此特定病例中为DSRCT）的疑难诊断。
