Background:
Malignant lymphoma involving the prostate is rare, and to the authors' knowledge the factors determining patient outcome have not been studied in a large series.
Methods:
The authors evaluated the clinical 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 predictive of patient outcome.
Results:
Lymphoma tended to occur in elderly men, with a mean age at diagnosis of 62 years (range, 5-89 years), although 6 patients were age < 40 years (ages 5, 19, 30, 32, 38, and 38 years, respectively). clinical signs and symptoms were due to lower urinary tract obstruction. twenty-two patients (35%) presented with primary extranodal lymphoma of the prostate with a variety of histologic subtypes, including small lymphocytic (4 patients); follicular center cell, diffuse, small cell (2 patients); follicular center cell, grade 1 (according to the revised european-american classification (small cleaved) (1 patient); grade 2 (mixed) (1 patient); diffuse large b-cell (12 patients); and high grade b-cell lymphoma, burkitt-like (2 patients). at the time of presentation, none of these patients had hepatosplenomegaly, inguinal lymphadenopathy, or an abnormal complete blood count. thirty other patients (48%) with previously documented lymphoma at other sites developed prostatic involvement; these secondary prostatic lymphomas displayed a variety of subtypes, including small lymphocytic (8 patients, all with concomitant leukemia); follicular center cell lymphoma, diffuse, small cell (2 patients); follicular center, grade 1 (small cell) (1 patient); follicular center, grade 2 (1 patient); diffuse large b-cell (11 patients); peripheral t-cell lymphoma (2 patients); high grade b-cell lymphoma, burkitt-like (1 patient); burkitt's lymphoma (1 patient); hodgkin's lymphoma (nodular sclerosing [1 patient] and mixed cellularity [1 patient]); and unknown (1 patient). ten cases were not classifiable as primary or secondary lymphomas. twenty-five patients died of malignant lymphoma, 14 died of unknown or other causes, 18 patients were alive 12-20 months after diagnosis (8 primary and 10 secondary tumors; 3 had persistent lymphoma; all treated since 1981), and 5 were lost to follow-up. lymphoma specific survival was 64% at 1 year (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 involvement between primary and secondary lymphoma (23 months vs. 28 months, respectively) or among histologic types.
Conclusions:
Although malignant lymphoma involving the prostate is rare, it should be considered in the differential diagnosis of lower urinary tract obstruction, particularly in patients with a previous history of lymphoma.