Leydig cell tumours of the testis and variants

Epidemiology

Leydig cell tumours constitute 1-3% of all testicular tumours.

Clinical features

In children, they may present with isosexual pseudoprecocity. In adults, they present with a mass and/or gynaecomastia.

Histopathology

The usual appearance is of sheets of polygonal cells with abundant eosinophilic cytoplasm. they may be divided by hyalinised fibrous septa into lobules. Crystals of Reinke may be seen in 30-70% of cases. The presence of lipid may cause vacuolation.

Variants include:

• pseudoglandular or pseudofollicular
  

• microcystic
  
• myxoid
  
• small cells with scanty cytoplasm
  
• lipid-rich adrenocortical-like
  
• calcification, which may be psammomatous and ossification
  
• adipose metaplasia1; the adjacent Leydig cells may contain lipid droplets.
  
• spindle cell differentiation1; the spindle cell component may be bland or sarcomatoid

Immunohistochemistry2

Immunohistochemistry of variants1

Differential diagnosis

• Leydig cell hyperplasia

• sex-cord-stromal tumour (unclassified) with incomplete Leydig cell differentiation.

• Testicular "tumour" of the adrenocortical syndrome (TTAGS); may show fatty metaplasia, sometimes with haemopoiesis. There is prominent lipofuscin and an absence of Reinke crystals.

• Large cell calcifying Sertoli cell tumour: frequently bilateral / multifocal, lacks Reinke crystals

• If lipid droplets present, seminoma, but Leydig cell tumours lack abundant glycogen and lack lymphocytic / granulomatous infiltrate.

• Coalesced lipid droplets may resemble microcystic spaces of yolk sac tumour.

• Malakoplakia

• Plasmacytoma

Prognosis

• All childhood Leydig cell tumours are benign.

• About 10-17% of adult cases are malignant. Features associated with malignancy are2:

  • increasing age

  • large size (>5 cm)

  • infiltrative margins / invasion beyond the testis

  • lymphovascular invasion

  • marked nuclear pleomorphism

  • tumour necrosis

  • mitotic index >3/10HPF / atypical mitotic figures

• A spindle cell component is only associated with malignant behavior if it is sarcomatoid1.

References

1Ulbright, T. M., J. R. Srigley, et al. (2002). "Leydig cell tumors of the testis with unusual features: adipose differentiation, calcification with ossification, and spindle-shaped tumor cells." Am J Surg Pathol 26(11): 1424-33.

2Shanks JH, Iczkowski KA. Non-germ cell tumours of the testis. Current Diagnostic Pathology 2002;8:83-93.

3McCluggage, W. G., Shanks, J. H., Whiteside, C., Maxwell, P., Banerjee, S. S., Biggart, J. D. Immunohistochemical study of testicular sex cord-stromal tumors, including staining with anti-inhibin antibody. Am J Surg Pathol 1998;22:615.

4Iczkowski, K. A., Bostwick, D. G., Roche, P. C., Cheville, J. C. Inhibin A is a sensitive and specific marker for testicular sex cord- stromal tumors. Mod Pathol 1998;11:774.

5Kommoss, F., Oliva, E., Bittinger, F., Kirkpatrick, C. J., Amin, M. B., Bhan, A. K., Young, R. H., Scully, R. E. Inhibin-alpha CD99, HEA125, PLAP, and chromogranin immunoreactivity in testicular neoplasms and the androgen insensitivity syndrome. Hum Pathol 2000;31:1055-61.

6Busam, K. J., Iversen, K., Coplan, K. A., Old, L. J., Stockert, E., Chen, Y. T., McGregor, D., Jungbluth, A. Immunoreactivity for A103, an antibody to melan-A (Mart-1), in adrenocortical and other steroid tumors. Am J Surg Pathol 1998;22:57-63.

7Kaufmann, O., Koch, S., Burghardt, J., Audring, H., Dietel, M. Tyrosinase, melan-A, and KBA62 as markers for the immunohistochemical identification of metastatic amelanotic melanomas on paraffin sections Mod Pathol 1998;11:740-6.

This page last revised 30.11.2002.

©SMUHT/PW Bishop