Carcinoma in situ of the testes: diagnosis by aspiration flow cytometry

Carcinoma in situ of the testis: review of biological and clinical features

Carcinoma in situ of the testis (CIS) is the uniform precursor of testicular germ-cell tumours. Morphologically, CIS consists of large, intratubular, gonocyte-like cells with large nuclei and abundant glycogen. CIS cells are probably derived from primordial germ cells and are supposed to be present in the testis of a future testis cancer patient at the time of birth. CIS cells appear to spread inside the seminiferous tubules until CIS progresses to invasive cancer. Diagnosis is best achieved by surgical biopsy of the testis and subsequent immunohistological staining of placental alkaline phosphatase (PlAP). This enzyme is present in embryonal germ cells, CIS and seminoma as well as several other types of germ-cell tumour but usually not in normal germ cells. CIS is found in testicular tissue adjacent to testicular germ-cell tumours in about 90% of cases, and it is observed in all clinical groups known to be at risk for testicular cancer: cryptorchidism (2% to 4%), infertility (0% to 1%), ambiguous genitalia (25%) and contralateral testis of patients with testicular cancer (5%). Conversely, CIS is found in less than 1% of the normal male population, and this prevalence corresponds well to the life-time risk of testicular cancer in males. If CIS is left untreated, there is a 50% probability of progressing to frank germ-cell neoplasm within 5 years. Localised low-dose radiotherapy to the testis eradicates CIS and germ cells, while Leydig cells are preserved. The patient can thus be spared orchiectomy and hormone supplementation. Currently, dose-reduction studies are looking for the optimal radiation dose, which is expected to be around 14 to 16 Gy. After chemotherapy, there is a cumulative risk of 42% for recurrence of CIS within 10 years. The concept of CIS offers the chance of very early detection of testicular cancer and organ-preserving early treatment.

Cytogenetic evidence that carcinoma in situ is the precursor lesion for invasive testicular germ cell tumors

A cytogenetic study of two cases of carcinoma in situ of the testis (CIS) and their adjacent invasive tumors, one a nonseminomatous germ cell tumor (NS) and one a seminoma (SE), revealed similarities in chromosomal pattern between the CIS and the invasive lesion in the same patient. These findings present for the first time cytogenetic evidence that CIS of the testis and its adjacent germ cell tumor are clonally related, which suggests that the CIS is indeed the precursor lesion of the invasive tumor.

Carcinoma in situ of the testis detected by DNA flow cytometry of testicular fine-needle aspirates

Testicular carcinoma in situ (CIS) is usually diagnosed histologically on surgical biopsies. The present study was performed to test an alternative approach--DNA flow cytometry (FCM) of testicular fine-needle aspirates (FNA)--for the detection of this lesion. FNAs from 18 cases of testicular germ cell tumors (TGCT) and tumor adjacent parenchyma were analysed by DNA FCM. DNA histograms of all cell nuclei and histograms representing selectively the hyperdiploid compartment were analysed. The presence and extention of CIS were determined by histology and immunohistochemistry. In 16 of 18 cases, CIS was histologically present, whereas aneuploid peaks were detected in only 11 cases in DNA histograms of all cell nuclei. In the analysis of the histograms of the hyperdiploid region, 4 additional cases of CIS could be identified increasing the sensitivity to 15/16 cases (93.8%). In all but one case, the DNA indices of CIS and invasive tumors were identical. The study demonstrates that DNA FCM of testicular FNAs using the described data acquisition and analysis could also be applicable for detection of CIS in a clinical situation.

Pre-treatment DNA ploidy of sperm cells as a predictive parameter of post-treatment spermatogenesis in patients with testicular cancer

OBJECTIVE

To evaluate DNA flow cytometry (DNA FCM) as a means of predicting post-treatment spermatogenesis in patients with testicular cancer.

SUBJECTS AND METHODS

After unilateral orchidectomy and before further treatment (pre-treatment), light microscopic sperm cell analysis and FCM were performed in 96 patients in whom post-treatment sperm cell counts were available > or = 2 years after therapy. Twenty-nine patients had not received any cytotoxic treatment after orchidectomy, whereas 64 had received either abdominal radiotherapy [37] or 3-4 cycles of cisplatin-based chemotherapy [27]. Three patients had both chemotherapy and radiotherapy. A control group consisted of 26 healthy age-matched men.

RESULTS

In the pre-treatment situation 43% of the patients had low sperm counts (< 10 x 10(6)/ml). A median of 38 months after treatment the median sperm cell density had increased significantly, independent of treatment, but was still less than that of the control group. All control specimens, but only 66% of the patients' ejaculates, contained cells of which more than 90% were classified as being condensed DNA haploid sperm cells. The median percentages of cells classified as non-condensed DNA haploid, as DNA diploid or as being above DNA diploid cells were increased in the patients' samples as compared with those of the controls, both before and after treatment.

CONCLUSION

Spermatogenesis is quantitatively and qualitatively impaired in patients with newly diagnosed testicular cancer. Long-term recovery is relatively independent of routine treatment but is related to the pre-treatment sperm cell density. For the whole series of patients DNA FCM parameters did not yield independent parameters which predicted recovery of spermatogenesis. In patients in whom no sperm cells were found by light microscopy of the seminal fluid the demonstration of > or = 30% condensed DNA haploid cells was correlated with post-treatment recovery of spermatogenesis.

Prevalence of bilateral testicular germ cell tumours and early detection based on contralateral testicular intra-epithelial neoplasia

The prevalence of bilateral tumours was found to be 4% in a retrospective analysis of 531 consecutive patients with testicular germ cell tumours. Patients with bilateral tumours were younger when their first tumour was diagnosed than those who had only 1 testicular tumour. Bilateral undescended testis was more frequent in 21 patients with bilateral tumours than in the total population of patients examined (2 of 21 versus 10 of 452, i.e. 9.5% versus 2.2%). Histology and unilateral undescended testis were not helpful in identifying patients at risk of developing a second tumour. In a separate study, 76 consecutive patients with unilateral testicular cancer underwent contralateral testicular biopsy at the time of orchiectomy. Five patients had testicular intra-epithelial neoplasia (TIN, so-called carcinoma in situ) in the contralateral testis; 1 of these patients had a history of bilateral undescended testis and 4 had an increased level of serum follicle stimulating hormone post-operatively. None of the other 71 patients had developed a second tumour after a median observation time of 30 months. Testicular biopsy and a search for TIN appear to be a safe method for the early identification of the patients at risk of developing a contralateral testicular tumour.