Primary neuroectodermal tumour of the testis

Benign and Malignant Neoplasms of the Testis and Paratesticular Tissue

Benign and malignant tumors of the testes and paratesticular tissues present an interesting spectrum of diagnostic entities often encountered in routine surgical pathology practice. Germ cell tumors are the most common tumors of the testes and, despite a rising incidence, have excellent prognosis because of their radiosensitivity and/or effective chemotherapeutic agents. The proper classification of these tumors aids in the choice of appropriate treatment options. This article reviews benign and malignant neoplastic entities of the testes and paratesticular tissues and illustrates the classic pathologic characteristics. The differential diagnosis, along with ancillary studies, clinical significance, and presentation are discussed also.

Ewing's sarcoma of the urogenital tract

This article reviews the current available information on Ewing's sarcoma of the urogenital tract, focusing on the presentation, diagnosis, and therapeutic management of this uncommon entity. Because of the rapid local growth of these tumors, an immediate decision for treatment initiation is mandatory. The classical presentation depends mainly on the site of involvement of these tumors, involving a palpable mass, hematuria, and pain. No specific diagnostic imaging is available to date, and the only diagnostic method remains histological examination in combination with immunohistochemistry. Treatment involves primary surgical resection of all tumor tissues followed by adjuvant multi-agent chemotherapy. Overall survival is poor, although a 13-year survival has been reached in one case.

Primitive neuroectodermal tumor arising in a testicular teratoma with retroperitoneal metastasis: report of an interesting case with review of literature

Teratomas with malignant transformation occur in approximately 3 to 6% of patients with metastatic germ cell tumors treated with platinum-based chemotherapy. The histology of the nongerm cell (somatic) malignant elements most commonly includes carcinoma and various types of sarcomas; however, so far as the primitive neuroectodermal tumors (PNETs) are concerned the experience is quite limited. There are only seven documented case reports and occasional series of PNET in association with testicular teratoma either in the primary site or in the metastatic location. We report a relatively unusual case of PNET arising in a malignant mixed germ cell tumor in a 35-year-old man.

Pathology of germ cell tumors of the testis

BACKGROUND

An increasing incidence of testis tumors has been noted over the second half of the 20th century. Congenital malformation of the male genitalia, prenatal risk factors, nonspecific and specific exposures in adulthood, and male infertility have all been associated with the etiology of germ cell tumors.

METHODS

The histologic classification, pathology, and current concepts of testicular germ cell tumors are reviewed.

RESULTS

Germ cell tumors occur at all ages. The tumors are identified as pure form (those of one histologic type) and mixed form (more than one histologic type). Over half of germ cell tumors consist of more than one cell type, requiring appropriate sampling for the correct diagnosis and correlation with the serum tumor markers. Burned-out germ cell tumors may occur in patients with metastatic disease with no gross evidence of a testicular tumor.

CONCLUSIONS

Appropriate management of testis tumors relies on accurate pathology and classification of these tumors.

Secondary neoplasms of the male genital tract with different patterns of involvement in adults and children

AIMS

The incidence, presentation and macroscopic and histological features of secondary neoplasms of the male genital tract are described with reference to their differential diagnosis.

METHODS AND RESULTS

A retrospective study of cases from the Royal London Hospital yielded a total of 31 secondary neoplasms involving the testis: 14 at postmortem examination and 17 surgical specimens. Nine cases were leukaemias: six acute lymphoblastic and two acute myeloid leukaemias in children, and one chronic lymphocytic leukaemia in an adult. The commonest primary sites of metastases to the testis were prostate (six cases), stomach (five cases) and lung (three cases). There were two malignant melanomas and isolated examples of metastases from the adrenal gland (neuroblastoma), cerebellum (medulloblastoma), soft tissue (alveolar rhabdomyosarcoma), pancreas and rectum. Of the metastases from solid tumours, 12 involved the right testis only, three involved the left and four were bilateral. In seven of these cases there were multiple testicular nodules, in seven there was a single mass, and in the rest there was diffuse involvement. Secondary neoplasms represented 4.6% of all testicular neoplasms at autopsy, and 1.6% in surgical specimens. There were five secondary penile neoplasms: two each from the pancreas and prostate and one from the bladder. Two neoplasms metastatic to the spermatic cord, both from a gastric primary, were included in the series.

CONCLUSIONS

Secondary neoplasms of the testis occur with a frequency comparable to other sites in the genitourinary tract, and metastases to the spermatic cord, epididymis, and penis, are rare in comparison. Disseminated neoplasms rarely present initially at this site and are histologically distinctive in adults, but in children they must be distinguished from primary small round blue cell tumours.

Primitive neuroectodermal tumors arising in testicular germ cell neoplasms

Twenty-nine young men (mean age 29 years) had primitive neuroectodermal tumors (PNETs) arising in germ cell tumors (GCTs). Nine patients had PNETs confined to the testis, eight patients had PNETs in the testis and at metastatic sites, and 12 patients had PNETs identified only at extratesticular sites. Immunohistochemistry was of use in the further classification of these PNETs as neuroblastoma, medulloepithelioma, peripheral neuroepithelioma, or ependymoblastoma. The histologic pattern of PNETs in the testis (neuroblastoma or medulloepithelioma) did not predict which tumors metastasized. PNETs localized to the testis did not affect prognosis. Eight patients with no PNETs outside the testis were free of disease 1 month to 10 years after diagnosis. PNETs in extratesticular sites were an adverse prognostic factor. Nineteen patients with extratesticular PNETs had adequate clinical follow-up. Thirteen are dead of disease from 4 months to 5 1/2 years (mean 26 months) after diagnosis, four are alive with disease 6 months to 2 years after diagnosis, and two have no evidence of disease with short follow-up (6 and 17 months). Mean survival was longer (34 months) for patients whose extratesticular PNET was neuroblastoma than for those with other types of PNETs (13 months). Chemotherapy directed against GCTs was not effective in patients who developed metastatic PNETs of GCT origin. We conclude that extratesticular PNETs in patients with testicular GCTs are usually fatal, but patients with neuroblastomatous metastases may have a more prolonged course.

Bipolar (neural and myoblastic) phenotype in cell lines derived from human germ cell tumours of testis

Non-seminomatous germ cell tumours of the testis (NSGCT) form a heterogeneous group of neoplasms. Cell lines derived from NSGCT may provide useful data concerning the biology of neoplasic precursor germ cells, differentiation of tumour stem cells and the relationship between various tissue components of these tumours. Four NSGCT were studied, two mixed tumours composed of teratocarcinoma, yolk sac and trophoblastic elements, and two malignant teratomas with a massive neuroectodermal component, equivalent to primary neuroectodermal tumours (PNET) of the testis. The explanted tumours gave rise to various cell populations, including epitheloid cells, flattened large cells, spindle cells and tear drop cells of neuroblastic type. Ultrastructurally, cultured cells expressed various degrees of neural and muscular differentiation: neurosecretory granules, intermediate filaments of glial nature, and filaments resembling Z-bands. Cultured cells showed the expression of several neural and muscular markers, including neurofilaments, cytokeratin, actin, desmin, neuron-specific enolase, glial fibrillary acidic protein and HNK-1. In addition, three cases expressed HBA-71 antigen and two expressed MyoD1 protein. All cases were aneuploid, and an isochromosome 12p, i(12p), was detected in three cases. Myoblastic and neural cells are the predominant tumour cells that grow in vitro, independent of the nature and composition of the primary germ cell tumour. A histogenetic relationship between germ cell tumours and small round cell tumours of childhood is suggested.

Malignant peripheral primitive neuroectodermal tumor (PNET) of the kidney

We describe a 61-year-old patient with primitive neuroectodermal tumor (PNET) arising from the kidney. Despite intensive treatment including surgery, combination chemotherapy and radiotherapy, rapid progression of the tumor was encountered and the patient died within six months with widespread disease. This appears to be the first recorded case of PNET of the kidney.

Non-germ cell tumors of testis

Testicular tumors of non-germ cell origin represent from 5 percent to 10 percent of all testicular neoplasms. Included in this group are sex cord/gonadal stromal tumors, most originating from Leydig or Sertoli cells, mixed tumors, and tumors of mesenchymal or hematopoietic origin. In addition, various miscellaneous lesions, tumor-like conditions, and secondary testicular tumors may be classified as non-germ cell tumors. This review covers the presentation, diagnosis, and treatment of these rare lesions.