Primary testicular lymphoma

Pathology Page Primary Testicular Lymphoma rimary testicular lymphoma occurs predominantly in men older than 60 years. In this age group lymphoma is the most common primary malignant testicular neoplasm. Overall primary testicular lymphoma accounts for 2% of testicular neoplasms, 2% of high grade lymphomas and 5% of extranodal lymphomas in men.1,2 Although 85% of patients are 65 years old or older at presentation, primary testicular lymphoma also occurs rarely in pediatric patients, most of whom are prepubertal.3 In contrast to testicular lymphomas in adults, of which 40% to 60% are primary (stage IE), the majority of testicular lymphomas in children represent secondary involvement of the testis by Burkitt’s, diffuse large B-cell or lymphoblastic lymphoma. Follicular lymphoma is the most frequently reported type of primary testicular lymphoma in the pediatric age group, whereas diffuse large B-cell lymphoma accounts for 80% to 90% of cases in adults. The most common clinical presentation is a unilateral testicular mass. Bilateral involvement at initial presentation is rare except with lymphoblastic lymphoma.1 Fever, night sweats and weight loss are rarely encountered with primary testicular lymphoma. Sonography typically displays discrete hypoechoic lesions that are indistinguishable from germ cell neoplasms. Lymphoma may be multifocal, and in some cases diffuse effacement of the testis is evident with or without involvement of peritesticular soft tissues. Gross inspection of the cut surface of the orchiectomy specimen reveals single or multiple poorly defined, tan-gray lesions that infiltrate or entirely replace the testicular parenchyma with varying amounts of associated hemorrhage and/or necrosis.1,2 Involvement of the epididymis, spermatic cord or adjacent soft tissues may be grossly apparent (fig. 1). Microscopically tumors consist of sheets of small, round, blue cells that diffusely infiltrate between intact seminiferous tubules and sometimes infiltrate the seminiferous tubules (fig. 2). Spermatogenic arrest, interstitial fibrosis and tubular hyalinization are P FIG. 2. Lymphoma cells fill and expand interstitium, leaving seminiferous tubules intact. commonly seen. Ancillary diagnostic techniques such as immunohistochemical stains, polymerase chain reaction gene rearrangement studies and/or flow cytometry are often used to confirm the presence of a monoclonal neoplastic lymphoid proliferation and help subclassify the lesion. Differential diagnosis primarily includes classic seminoma and spermatocytic seminoma. Granulomatous orchitis and malacoplakia may also mimic lymphoma histologically.1,2 Primary (stage IE) testicular lymphoma has the worst prognosis of all extranodal lymphomas, with overall 5-year survival rates of 70% to 79%.1 However, these rates are more favorable than the overall 5 and 10-year survival rates for all stages and histological lymphoma subtypes combined (37% to 48% and 19% to 27%, respectively). In pediatric patients the prognosis is excellent with no reported deaths at 18 to 44-month followup after orchiectomy and chemotherapy.3 John D. Miedler and Gregory T. MacLennan Department of Pathology University Hospitals of Cleveland Case Western Reserve University Cleveland, Ohio REFERENCES 1. FIG. 1. Testicular parenchyma is diffusely effaced by tumor, which also appears to involve epididymis and spermatic cord. 0022-5347/07/1786-2645/0 THE JOURNAL OF UROLOGY® Copyright © 2007 by AMERICAN UROLOGICAL ASSOCIATION Marx A and Woodward PJ: Lymphoma and plasmacytoma of the testis and paratesticular tissues. In: WHO Classification of Tumours: Pathology and Genetics. Edited by JN Eble, G Sauter, JI Epstein and IA Sesterhenn. Lyon, France: IARC Press 2004; pp 263–264. 2. Lagrange JL, Ramaioli A, Theodore CH, Terrier-Lacombe MJ, Beckendorf V, Biron P et al: Non-Hodgkin’s lymphoma of the testis: a retrospective study of 84 patients treated in the French anticancer centres. Ann Oncol 2001; 12: 1313. 3. Heller KN, Teruya-Feldstein J, La Quaglia MP and Wexler LH: Primary follicular lymphoma of the testis: excellent outcome following surgical resection without adjuvant chemotherapy. J Pediatr Hematol Oncol 2004; 26: 104. 2645 Vol. 178, 2645, December 2007 Printed in U.S.A. DOI:10.1016/j.juro.2007.09.012