Testicular Intraepithelial Neoplasia: The Precursor of Testicular Germ Cell Tumors

Abstract

Testicular intraepithelial neoplasia (TIN; so-called carcinoma in situ of the testis) is the uniform precursor of testicular germ-cell tumors. TIN is derived from embryonal gonocytes and is present in the testis of a future testis cancer patient at the time of birth. TIN spreads inside the seminiferous tubules until it progresses to invasive cancer. Diagnosis is best achieved by surgical biopsy of the testis and subsequent im-munohistological staining of placental alkaline phosphatase. This enzyme is present in gonocytes, TIN, and seminoma as well as in several other types of germ-cell tumors but not in normal germ cells. TIN is found in testicular tissue adjacent to testicular germ-cell tumors and is observed in all clinical groups known to be at risk for testicular cancer: cryptorchidism (2-3%), infertility (1%), ambiguous genitalia (25%), in contralateral testis of patients with testis cancer (3-6%). Conversely, TIN is not found in the normal male population.If TIN is left untreated, there is a 50% probability of progressing to frank germ-cell neoplasm within 5 years. Localized radiotherapy to the testis with 18-20 Gy eradicates TIN and germ cells while Leydig cells are preserved. The patient can thus be spared orchiectomy and hormone supplementation. The concept of TIN offers the chance of very early detection of testis cancer and organ-preserving early treatment.

Testicular Dermoid Cyst in a 10-Year-Old Child: Case Report and Discussion of Etiopathogenesis, Diagnosis, and Treatment

“…In contrast to the general understanding of the patho genesis of dermoid and epidermoid cysts, the occurrence of these cysts within the testis has been considered to present the monophasic development of a teratoma [6,7], It has long been established that testicular epidermoid cysts, first described by Dockerty and Priestly [8], are benign lesions that have not been associated with metastases or recurrence [9], These clinical observations as well as the absence of TIN (so-called carcinoma in situ testis), the precursor of all testicular germ cell tumors [10][11][12], in the adjacent testicular tissue in adults, have challenged this hypothesis in adults for a long time.…”

Granulomatous Orchitis - An Analysis of Clinical Presentation, Pathological Anatomic Features and Possible Etiologic Factors

“…Germ cell tumors, especially embryonal carcinoma and seminoma, as well as lymphomatous involvement of the testis bear histologically a resemblance to granulomatous orchitis and therefore have to be excluded [29], as in our cases. TIN, the uniform precursor of testicular germ cell tumors, is derived from embryonal gonocytes [30][31][32] and best identified by staining for PLAP [33,34], We failed to identify atypical germ cells in those cases where tubular destruction had not yet been complete. PLAP could not be detected either.…”

Combination of Hypospadias and Maldescended Testis as Cardinal Symptoms in Gonosomal Chromosome Aberrations*

“…Giwercman et al (10) recommended a testicular biopsy in young adults. According to the authors, the contralateral testis should also be biopsied since the prevalence of the contralateral CIS correlates with that of bilateral testicular tumor (6). In consequence, the possibility of a loss oftesticular endocrine function and alterations of tumor metastasizing should be considered.…”