Case 91 - Discussion

Uploaded: 2007-09-07, Updated: 2011-01-10


Microscopic Description
The  testicular tissue is nearly completely replaced by diffuse infiltration of large atypical cells. Rare residual seminiferous tubules are present with interstitial infiltration of tumor cells. The tumor cells are large with moderate to abundant cytoplasm, large and variable nuclei. Prominent nucleoli are seen in some tumor cells. Apoptosis and mitosis are common. The tumor is largely confined by the tunica albuginea and focally invades into fat tissue. The spermatic cord resection margin is positive for the tumor.

Immunohistochemical Studies

The  tumor cells are positive for CD45, CD20, CD79a, CD5, Bcl-2 and BCL-6, but negative for CD3, CD10, CD30, NSE and PLAP. Nearly 100% of the tumor cells are positive for Ki-67.

A clonal Immunoglobulin Heavy chain gene rearrangement is detected by DNA amplification. An extra copy of IgH with a deletion of the 5' (telomeric) portion is present in 89% of the interphase cells from this tissue section. Additional studies were negative for rearrangements of the CMYC (8q24) region in this tissue section.


Primary B-Cell Lymphoma of Testis

  • Most common testicular tumor in elderly persons

  • 50% bilateral testicular tumors are lymphomas

  • Mostly DLBCL