Intratubular germ cell neoplasia: associated infertility and review of the diagnostic modalities

The incidence and histological characteristics of intratubular germ cell neoplasia in postpubertal cryptorchid testis

PURPOSE

It is well known that testicular germ cell tumors arise with increased frequency in patients with cryptorchidism. In addition, intratubular germ cell neoplasia (ITGCN) is a precursor lesion to testicular germ cell tumor. Approximately 50% of patients with ITGCN will develop an invasive of testicular germ cell tumors within 5 years. Therefore, we evaluated that the incidence of ITGCN in postpubertal cryptorchidism.

MATERIALS AND METHODS

Between January 2002 and August 2012, orchiectomy specimens from 31 postpubertal patients (aged 12 or over) with cryptorchid testis were reviewed. The specimens were evaluated for ITGCN using immunohistochemical stains of placental-like alkaline phosphatase and Oct 3/4 with routine hematoxylin-eosin stain. Additionally, the degree of spermatogenesis was assessed using the Johnsen score.

RESULTS

Mean age was 34 years (range, 17 to 74 years) at surgery. All patients were diagnosed as unilateral cryptorchidism. One patient (3.2%) of 20-year-old had ITGCN in surgical specimen with all positive markers. Histological assessment of spermatogenesis showed that mean Johnsen score was 3.42 (range, 1 to 9). Majority of patients (27 of 31) presented impaired spermatogenesis with low Johnsen score lesser than 5.

CONCLUSIONS

Considering the risk of malignancy and low spermatogenesis, we should perform immunohistochemical stains and discuss preventative orchiectomy for the postpubertal cryptorchidism.

Double immunolabeling by the RBM and the PLAP markers for identifying intratubular (in situ) germ cell neoplasia of the testis

Identification of intratubular germ cell neoplasia (carcinoma in situ, CIS) of the testis is a diagnostic challenge, and markers are sorely needed to assist in accurately identifying the lesion. RNA-binding motif (RBM) protein, encoded by the Y chromosome, is expressed exclusively and consistently in differentiated male germ cells, while it is absent in neoplastic germ cells. Another immunohistochemical marker, placental alkaline phosphatase (PLAP), is commonly used for the detection of undifferentiated germ cells. The current study demonstrates that simultaneous use of the immunohistochemical markers, RBM and PLAP, by double immunolabeling enhances the accuracy of diagnosing CIS, a preinvasive testicular neoplasm.