Nistal Manuel, Paniagua Ricardo, Riestra María Luisa, Reyes-Múgica Miguel, Cajaiba Mariana Morais
Department of Morphology, School of Medicine, Universidad Autonoma de Madrid, Madrid, Spain.
Am J Surg Pathol. 2007 Aug;31(8):1269-76. doi: 10.1097/PAS.0b013e318030979a.
Mixed atrophy of the testis (MAT), a frequent finding in biopsies of formerly cryptorchid and/or infertile patients, is defined as the synchronous occurrence of both seminiferous tubules containing germ cells and Sertoli cell only-tubules in variable proportions. In tubules containing germ cells, different types of abnormalities in spermatogenesis may be seen. The presence of adult spermatids in the biopsy, even in small numbers, correlates with successful spermatozoa retrieval for "in vitro" fertilization techniques. Currently, it is unknown whether precursor lesions of MAT can be identified in cryptorchid patients during childhood.
Eighteen formerly cryptorchid adults who had undergone testicular biopsies in childhood had a repeat testicular biopsy to evaluate infertility. In prepubertal biopsies, abnormalities of the testicular parenchyma were classified into types I (slight alterations), II (marked germinal hypoplasia), and III (severe germinal hypoplasia). In postpubertal biopsies, the percentage of tubules containing germ cells and Sertoli cell only-tubules were estimated, as well as the presence of complete spermatogenesis. Abnormalities in spermatogenesis were classified into lesions of the adluminal or basal compartments of seminiferous tubules.
Comparison between prepubertal and postpubertal biopsies revealed that most specimens developing from type III lesions presented with incomplete spermatogenesis (P<0.0001) and more severe lesions of the germinal epithelium (P=0.049).
Type III lesions correlated with MAT characteristics that confer a worse prognosis for in vitro fertilization. Thus, MAT characteristics may be predicted in prepubertal cryptorchid patients, allowing a fertility prognosis. The pathogenesis of these lesions, and their possible inclusion into the spectrum of the testicular dysgenesis syndrome, are discussed.
睾丸混合性萎缩（MAT）是既往隐睾和/或不育患者活检中常见的表现，定义为含有生殖细胞的生精小管和仅含支持细胞的小管以不同比例同时出现。在含有生殖细胞的小管中，可观察到精子发生的不同类型异常。活检中存在成年精子细胞，即使数量很少，也与“体外”受精技术成功获取精子相关。目前，尚不清楚在儿童期隐睾患者中是否能识别出MAT的前驱病变。
18名儿童期接受过睾丸活检的既往隐睾成年男性接受重复睾丸活检以评估不育情况。在青春期前活检中，睾丸实质异常分为I型（轻度改变）、II型（明显生精细胞发育不全）和III型（严重生精细胞发育不全）。在青春期后活检中，估计含有生殖细胞的小管和仅含支持细胞的小管的比例，以及是否存在完全精子发生。精子发生异常分为生精小管管腔或基底部分的病变。
青春期前和青春期后活检结果比较显示，大多数由III型病变发展而来的标本表现为精子发生不完全（P<0.0001）和生精上皮病变更严重（P=0.049）。
III型病变与MAT特征相关，这些特征对体外受精预后较差。因此，在青春期前隐睾患者中可预测MAT特征，从而进行生育预后评估。讨论了这些病变的发病机制及其可能纳入睾丸发育不全综合征范围的情况。
