p53: a good diagnostic marker for intratubular germ cell neoplasia, unclassified

Gastric adenocarcinoma with germ cell tumor components: a rare case report

Germ cell tumors (GCTs) often occur in male testes and female ovaries. Extragonadal GCTs account for approximately 2% to 5% of all GCTs and mainly occur in the mediastinum, retroperitoneum, and pineal gland. In this study, we reported a rare case of gastric adenocarcinoma with GCT components. The patient’s serum α-fetoprotein (AFP) level was higher than normal. Abdominal computed tomography (CT) showed a 10-cm × 10-cm tumor between the spleen and the bottom of the stomach. Gastric endoscopy indicated an ulcerative lesion extending from the bottom of the stomach to the antrum. Tissue biopsy identified the tumor as an adenocarcinoma. The patient underwent abdominal tumor resection, subtotal gastrectomy, D2 lymphadenectomy, and splenectomy. Postoperative histopathology showed that the tumor was a moderately to poorly differentiated adenocarcinoma. Immunohistochemistry analysis revealed positive staining for AFP, glypican-3, and placental alkaline phosphatase. Gastric adenocarcinoma with GCT components is particularly uncommon and rarely reported. Elevated serum AFP and/or β-human chorionic gonadotropin levels, abdominal CT, histopathology, and immunohistochemistry may help diagnose GCTs. Radical surgery resection is the primary treatment method for GCTs. Adjuvant chemotherapy and radiotherapy are effective for advanced GCTs.

Intratubular germ cell neoplasia of the testis and its associated cancers: the use of novel biomarkers

Recent advances in the understanding of the molecular pathology of testicular tumours have led to the identification of several new immunohistochemical markers for invasive and in situ germ cell neoplasms. OCT3/4 and NANOG are nuclear stains that have high sensitivity and specificity for the identification of intratubular germ cell neoplasia as well as seminoma and embryonal carcinoma. A potential pitfall in their application to the detection of intratubular germ cell neoplasia, as in other markers that represent oncofetal antigens, is their expression in non-neoplastic germ cells with 'delayed maturation'. SALL4, another nuclear stain, is positive for most germ cell tumours as a group and may be especially helpful in the distinction of these tumours from somatic carcinomas in non-testicular sites. Glypican 3 is a more sensitive marker for yolk sac tumour than alpha-fetoprotein. SOX2 and SOX17 may be useful for differentiating seminoma and embryonal carcinoma, especially following chemotherapy as embryonal carcinoma may lose CD30 expression in this setting. This article reviews the application of these immunohistochemical markers and others to the diagnosis of germ cell neoplasia with reference to older immunohistochemical stains when appropriate. Suggested immunohistochemical panels are described for individual tumour types.

Linking incomplete reprogramming to the improved pluripotency of murine embryonal carcinoma cell-derived pluripotent stem cells

Somatic cell nuclear transfer (SCNT) has been proved capable of reprogramming various differentiated somatic cells into pluripotent stem cells. Recently, induced pluripotent stem cells (iPS) have been successfully derived from mouse and human somatic cells by the over-expression of a combination of transcription factors. However, the molecular mechanisms underlying the reprogramming mediated by either the SCNT or iPS approach are poorly understood. Increasing evidence indicates that many tumor pathways play roles in the derivation of iPS cells. Embryonal carcinoma (EC) cells have the characteristics of both stem cells and cancer cells and thus they might be the better candidates for elucidating the details of the reprogramming process. Although previous studies indicate that EC cells cannot be reprogrammed into real pluripotent stem cells, the reasons for this remain unclear. Here, nuclei from mouse EC cells (P19) were transplanted into enucleated oocytes and pluripotent stem cells (P19 NTES cells) were subsequently established. Interestingly, P19 NTES cells prolonged the development of tetraploid aggregated embryos compared to EC cells alone. More importantly, we found that the expression recovery of the imprinted H19 gene was dependent on the methylation state in the differential methylation region (DMR). The induction of Nanog expression, however, was independent of the promoter region DNA methylation state in P19 NTES cells. A whole-genome transcriptome analysis further demonstrated that P19 NTES cells were indeed the intermediates between P19 cells and ES cells and many interesting genes were uncovered that may be responsible for the failed reprogramming of P19 cells. To our knowledge, for the first time, we linked incomplete reprogramming to the improved pluripotency of EC cell-derived pluripotent stem cells. The candidate genes we discovered may be useful not only for understanding the mechanisms of reprogramming, but also for deciphering the transition between tumorigenesis and pluripotency.