Ito J, Shinohara N, Koyanagi T, Hanioka K
Department of Pathology, Kawasaki Hospital, Okayama, Japan.
Pathol Int. 1998 Feb;48(2):151-9. doi: 10.1111/j.1440-1827.1998.tb03885.x.
Presented is the first Japanese case of ossifying renal tumor of infancy (ORTI), which is an extremely rare tumor and of which only nine cases have been reported in the literature. The patient was a four-month-old Japanese boy presenting as hematuria. A small nodular tumor (approximately 1 cm in size) protruded into the right pelvis from the superior caliceal region. Histologically the tumor originated from the tip of one medullary papilla and consisted of small rounded cells with a dense arrangement and several foci of minimally calcified osteoid lesions, including fewer but larger cells. Transition from the small to larger cells was suggested. The small cell only expressed vimentin, but the larger coexpressed vimentin, desmin, and epithelial membrane antigen. These findings suggested that the small cells differentiated to the larger cells with an epithelial nature associated somehow with osteoid formation. Embryonal metaplasia was assumed to occur in the collecting ducts entrapped by the tumor. The patient has been well without recurrence for more than 23 years. This is the longest survival period compared with other reported cases and confirms the benign nature of ORTI. It is absolutely crucial to make an accurate diagnosis of ORTI to avoid unnecessary treatment.
本文报道了日本首例婴儿骨化性肾肿瘤（ORTI），这是一种极为罕见的肿瘤，文献中仅报道过9例。该患者为一名4个月大的日本男婴，表现为血尿。一个小的结节状肿瘤（大小约1厘米）从肾上极区域突入右肾盂。组织学上，肿瘤起源于一个髓质乳头的尖端，由排列密集的小圆形细胞和几个微小钙化骨样病变灶组成，包括较少但较大的细胞。提示从小细胞向大细胞的转变。小细胞仅表达波形蛋白，但大细胞同时表达波形蛋白、结蛋白和上皮膜抗原。这些发现表明，小细胞分化为具有上皮性质且与骨样形成有某种关联的大细胞。推测肿瘤包绕的集合管发生了胚胎化生。该患者23年多来情况良好，无复发。与其他报道的病例相比，这是最长的生存期，证实了ORTI的良性性质。准确诊断ORTI以避免不必要的治疗至关重要。
