Billis Athanase, Freitas Leandro L L, Silva Frederico G C, Ferreira Ubirajara, Matheus Wagner E, Selegatto Ivan B, Oliveira Caio de, Tognoli Thais A, Etchebehere Elba C S C
Department of Anatomic Pathology.
Department of Urology.
Adv Anat Pathol. 2024 Nov 13. doi: 10.1097/PAP.0000000000000470.
Horseshoe kidney is a rare congenital anomaly with an unusually higher frequency of neuroendocrine tumors. Symptoms are rare, and, in most of the cases, are incidentally diagnosed. The clinical behavior of these tumors is heterogeneous and can be difficult to predict based on histology alone. Necrosis and percentage of Ki-67 may have a role in prognosis. Almost all tumors are carcinoids (well-differentiated neuroendocrine tumors) observed at an early age and with no sex dominance. It is not known the reason for the higher frequency of neuroendocrine tumors in horseshoe kidneys and the histogenesis is unknown. One of the hypotheses supports that renal carcinoid tumors may arise from neuroendocrine cells within foci of metaplastic or teratomatous epithelium within the kidney. With consonance with this hypothesis, there are reports of carcinoids in horseshoe kidneys associated with a cystic lesion lined by the intestinal epithelium, with mucinous differentiation and osseous metaplasia, arising in a mature teratoma of the kidney, arising within mature teratoma and clear cell renal cell carcinoma, with a mucinous cystadenoma element, and arising within mature cystic teratoma synchronous with primary adenocarcinoma. There is only one reported large cell neuroendocrine carcinoma of a horseshoe kidney in a 57-year-old Chinese woman. Herein, we report a patient that to the best of our knowledge is the first case of a combined well-differentiated neuroendocrine tumor and large-cell neuroendocrine carcinoma with rhabdoid features in horseshoe kidney. The histologic component of rhabdoid features expands the morphologic spectrum of neuroendocrine tumors in the horseshoe kidney. We provide a comprehensive review of the literature summarizing pertinent key clinical and pathologic aspects.
马蹄肾是一种罕见的先天性异常，神经内分泌肿瘤的发生频率异常高。症状罕见，在大多数情况下是偶然诊断出来的。这些肿瘤的临床行为具有异质性，仅根据组织学很难预测。坏死和Ki-67百分比可能对预后有影响。几乎所有肿瘤都是类癌（高分化神经内分泌肿瘤），发病年龄早，无性别差异。尚不清楚马蹄肾中神经内分泌肿瘤发生率较高的原因，其组织发生也不明。一种假说是，肾类癌可能起源于肾内化生或畸胎样上皮灶内的神经内分泌细胞。与此假说一致的是，有报道称马蹄肾类癌与肠上皮内衬的囊性病变相关，伴有黏液样分化和骨化生，发生于肾成熟畸胎瘤内，发生于成熟畸胎瘤和透明细胞肾细胞癌内，伴有黏液性囊腺瘤成分，以及与原发性腺癌同时发生于成熟囊性畸胎瘤内。仅报道过一例57岁中国女性马蹄肾的大细胞神经内分泌癌。在此，我们报告一例据我们所知是马蹄肾中首例合并高分化神经内分泌肿瘤和具有横纹肌样特征的大细胞神经内分泌癌的病例。横纹肌样特征的组织学成分扩展了马蹄肾神经内分泌肿瘤的形态学谱。我们对相关文献进行了全面综述，总结了相关的关键临床和病理方面。
