MALIGNANT-LYMPHOMA INVOLVING THE PROSTATE - REPORT OF 62 CASES

BACKGROUND, Malignant lymphoma involving the prostate is rare, and to the authors' knowledge the factors determining patient outcome have no t been studied in a large series. METHODS. The authors evaluated the c linical and pathologic findings in 60 cases of non-Hodgkin's lymphoma and 2 cases of Hodgkin's lymphoma involving the prostate. A variety of clinical and histologic findings were considered as factors predictiv e of patient outcome. RESULTS. Lymphoma tended to occur in elderly men , with a mean age at diagnosis of 62 years (range, 5-89 years), althou gh 6 patients were age < 40 years (ages 5, 19, 30, 32, 38, and 38 year s, respectively). Clinical signs and symptoms were due to lower urinar y tract obstruction. Twenty-two patients (35%) presented with primary extranodal lymphoma of the prostate with a variety of histologic subty pes, including small lymphocytic (4 patients); follicular center cell, diffuse, small cell (2 patients); follicular center cell, Grade 1 (ac cording to the revised European-American classification (small cleaved ) (1 patient); Grade 2 (mixed) (1 patient); diffuse large B-cell (12 p atients); and high grade B-cell lymphoma, Burkitt-like (2 patients). A t the time of presentation, none of these patients had hepatosplenomeg aly, inguinal lymphadenopathy, or an abnormal complete blood count. Th irty other patients (48%) with previously documented lymphoma at other sites developed prostatic involvement; these secondary prostatic lymp homas displayed a variety of subtypes, including small lymphocytic (8 patients, all with concomitant leukemia); follicular center cell lymph oma, diffuse, small cell (2 patients); follicular center, Grade 1 (sma ll cell) (1 patient); follicular center, Grade 2 (1 patient); diffuse large B-cell (11 patients); peripheral T-cell lymphoma (2 patients); h igh grade B-cell lymphoma, Burkitt-like (1 patient); Burkitt's lymphom a (1 patient); Hodgkin's lymphoma (nodular sclerosing [1 patient] and mixed cellularity [1 patient]); and unknown (1 patient). Ten cases wer e not classifiable as primary or secondary lymphomas. Twenty-five pati ents died of malignant lymphoma, 14 died of unknown or other causes, 1 8 patients were alive 12-20 months after diagnosis (8 primary and 10 s econdary tumors; 3 had persistent lymphoma; all treated since 1981), a nd 5 were lost to follow-up. Lymphoma specific survival was 64% at 1 y ear (95% confidence interval [CI], 51-80%), 50% at 2 years (95% CI, 36 -68%), 33% at 5 years, 33% at 10 years, and 16% at 15 years. There was no difference in median survival after diagnosis of prostatic involve ment between primary and secondary lymphoma (23 months vs, 28 months, respectively) or among histologic types. CONCLUSIONS. Although maligna nt lymphoma involving the prostate is rare, it should be considered in the differential diagnosis of lower urinary tract obstruction, partic ularly in patients with a previous history of lymphoma. Cancer 1998;83 : 732-8. (C) 1998 American Cancer Society.