Malignant lymphoma of the bladder: evidence from 36 cases that low-grade lymphoma of the MALT-type is the most common primary bladder lymphoma

A case of primary lymphoma of the bladder managed with multimodal therapy

BACKGROUND

A 65-year-old female patient presented to a urology department with macroscopic hematuria, dysuria, urinary frequency and urgency. One year previously, she had visited a urologist because of a 1-month history of hematuria, dysuria, urinary frequency and urgency. She had subsequently undergone successful, simultaneous surgeries for resection of a basal cell carcinoma of the nasal skin and lymphoma of the bladder.

INVESTIGATIONS

Physical examination, measurement of serum urea, creatinine and electrolyte levels, peripheral blood film evaluation, ultrasonography, intravenous pyelography, abdominal, thoracic and pelvic CT, bone marrow aspiration and biopsy, cystoscopy and pathologic examination.

DIAGNOSIS

Primary lymphoma of the bladder.

MANAGEMENT

Transurethral resection, chemotherapy, radiotherapy and follow-up comprising cystoscopy, biopsy, CT imaging and immunocytologic analyses of urine samples.

Primary non-hodgkin lymphoma of urinary bladder with nine years later renal involvement and absence of systemic lymphoma: a case report

AIMS

Primary bladder non-Hodgkin lymphoma (PBNHL) is very rare, especially as extranodal B-small lymphocytic lymphoma (B-SLL). Also, late isolated renal manifestation of PBNHL is extremely unusual. We report a very rare type of extranodal B-SLL of bladder wall with extremely unusual late isolated renal involvement, clinically manifested by nephrotic syndrome and incipient renal failure.

A CASE REPORT

A 56-year-old woman was presented with a solitary tumor of bladder wall, with history of dysuria and night sweating. A transvaginal needle biopsy of the tumor was performed, and diagnosis of primary extranodal B-SLL was made in the absence of bone marrow, lymph node, or blood involvement. She was treated with chemotherapy until the achievement of complete remission. Nine years later, she developed nephrotic syndrome. The renal biopsy revealed parenchymal lymphoma's involvement associated with glomerular lesion. Immunohistochemical analysis confirmed the same imunophenotype of lymphoma cells like in bladder wall nine years ago. Restaging procedure showed no evidence of disease elsewhere.

CONCLUSION

To our knowledge, it is the first case of association of very rare primary bladder B-SLL with late isolated renal involvement.

Lymphoepithelioma-like carcinoma of the urinary bladder--diagnostic and clinical implications

BACKGROUND

A 57-year-old man presented with a 4-week history of intermittent, painless frank hematuria. There were no other symptoms. He had no previous urologic history, is a nonsmoker, and works as a manual laborer.

INVESTIGATIONS

Physical examination, ultrasound of the urinary tract, and intravenous urography were all unremarkable. Urine microscopy confirmed more than 5 red blood cells per high-power field, but no malignant cells were seen on cytologic assessment. Flexible cystoscopy revealed a 3 cm, partially solid, solitary lesion on the right lateral wall of the bladder. The tumor was completely resected under general anesthesia.

DIAGNOSIS

Histologically, the tumor was described as a G3 pT1 transitional cell carcinoma of the bladder.

MANAGEMENT

Following the resection of a solitary recurrence 6 weeks after the initial tumor resection, the patient underwent a standard course of intravesical bacillus Calmette-Guérin therapy. Despite this, another tumor was identified 3 months later. Histologically, this tumor was described as a lymphoepithelioma-like carcinoma, of at least grade G3pT1. The patient underwent radical cystoprostatectomy with ileal conduit formation; no adjuvant systemic chemotherapy was given in light of complete tumor resection. The patient is under continuing, close clinical and radiologic observation and remains free of disease recurrence, 36 months postoperatively.

Non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue

The concept of mucosa-associated lymphoid tissue (MALT) lymphomas was introduced by Isaacson and Wright [Cancer 1983; 52:1410-1416] in 1983. After more than 20 years of clinical research MALT lymphomas are now recognized as a distinct subtype of non-Hodgkin's lymphoma (NHL) with unique pathogenic, histological, and clinical features. Although this subtype of NHL occurs frequently, optimal management remains elusive. This manuscript reviews features of the clinical presentation, diagnosis, pathology, molecular characteristics, and management of both gastric and non-gastric MALT lymphoma.

Thymic and pulmonary mucosa-associated lymphoid tissue lymphomas in a patient with Sjögren’s syndrome and literature review

Mucosa-associated lymphoid tissue lymphoma (MALToma) has been reported in several organs. Among MALTomas, thymic and pulmonary MALTomas are rare. The present report describes a patient with Sjögren's syndrome who presented thymic and pulmonary MALTomas. Although the exact pathogenetic relationship between these two tumours is uncertain, it is likely that the underlying immune dysregulation related to Sjögren's syndrome contributed to the occurrence and the unusual manifestation of MALTomas in this patient.

[Non-Hodgkin's lymphoma and urinary tract. About a case reported]

We pass to describe a case of non Hodgkin's secondary lymphoma with metachronic affectation in bladder and left kidney, in a patient with different extranodals locations. Both in bladder and kidney, it was a low grade lymphoma type B with centrofolicular cells. We suggest haematogenous dissemination and affinity of lymphomatous clone to the urinary tract. We establish some diagnostic considerations, such about the therapeutic management in this type of pathologies.

Non-Hodgkin lymphoma of the bladder

Lymphomas of the bladder are rare lesions, representing approximately 0.2% of the primary neoplastic lesions and approximately 1.8% of the secondary lesions in this organ. The authors report the case of a 41-year old patient with secondary lymphoma of the bladder occurring 2 years after treatment for non-Hodgkin lymphoma, diagnosed by biopsy of cervical lymph node, and analyze the clinical and prognostic aspects of bladder lymphomas.

Thymic MALT lymphoma

There has been no report on the MRI findings of primary thymic MALT lymphoma. We report the correlation between MRI findings and histopathology in four cases of this entity. While primary thymic MALT lymphomas exhibited diverse characteristics, the cystic components inside, which were clearly depicted on T2-weighted images, were considered to be pathognomonic. Primary thymic MALT lymphoma should be considered as one of the differential diagnoses of anterior mediastinal tumors having multilocular cysts that arise in patients with immunological abnormalities.

Urinary immunocytology for primary bladder B cell lymphoma

Urinary immunocytology is described as a diagnostic tool in a patient with a primary high-grade, large-cell, B cell lymphoma of the bladder. Lymphoma cells were distinguished from abundant leukocytes by immunocytologic staining for CD20. This technique might be useful in the differential diagnosis of patients with chronic bladder inflammation accompanied by pyuria.

Malignant Non-Urothelial Neoplasms of the Urinary Bladder: A Review

OBJECTIVES

Non-urothelial bladder tumors frequently present a diagnostic and therapeutic challenge. We review the peer-reviewed literature to summarize the available evidence on the etiology, diagnosis and optimal management of malignant non-urothelial bladder tumors.

METHODS

A comprehensive MEDLINE database search was performed. In addition, the proceedings of recent national and international urological and cancer society meetings were reviewed.

RESULTS

Primary non-urothelial bladder tumors are rare in Europe and North America representing less than 5% of all bladder lesions combined. A large number of risk factors have been implicated in the etiology of non-schistosomiasis-related squamous cell carcinoma, yet their exact pathomechanism remains poorly defined. Squamous cell carcinoma, adenocarcinoma, small cell carcinoma, sarcoma and carcinosarcoma/sarcomatoid tumors share an unfavorable prognosis despite aggressive surgical management that relates both to an aggressive biological behaviour as well as to an often times advanced stage at the time of diagnosis. Inflammatory pseudotumors are benign tumors of uncertain histogenesis that may mimic sarcomas. Paraganglioma, primary melanoma and lymphoma represent additional, exceedingly rare bladder tumors.

CONCLUSIONS

The systematic investigation of most non-urothelial bladder tumors is limited by the rarity of these lesions. A concerted effort of multiple institutions linked together in a national or international tumor registry will be necessary to advance our understanding of these tumors, evaluate treatment strategies and optimize patient outcome in the future.

Primary mucosa-associated lymphoid tissue (MALT) lymphoma arising from the male urethra. A case report and review of the literature

Primary non-Hodgkin's lymphomas rarely arise from the lower urinary tract, the urethra being the most uncommon site of origin. Herein, we report the immunohistochemical findings of a case of primary marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) arising from the male urethra. To clarify the clinicopathological findings of primary urethral lymphoma, we reviewed 14 previously reported cases. A 56-year-old man presented with gross hematuria. Cystourethroscopy demonstrated a nodular bulge of the urethral wall. Histologically, a transurethral biopsy specimen showed a dense lymphoplasmacytoid infiltrate in the urethral mucosa. The tumor cells were composed of centrocyte-like cells, plasma cells and plasmacytoid cells. A few plasma cells contained intracytoplasmic pseudoinclusions (Dutcher bodies). Immunohistochemical study revealed monotypic intracytoplasmic kappa-light chain in the plasma cells and plasmacytoid cells. The patient received a total of 50 Gy extrabeam irradiation. Follow-up 21 months later did not disclose any sign of local or other recurrences.

Extranodal marginal zone B cell lymphoma of MALT type involving the mucosa of both the urinary bladder and stomach

Primary lymphoma of the urinary bladder is a very rare tumour. A bladder tumour was found in a 57 year old man with obstructive dysuria. It was found by histological and immunohistohistochemical investigation to be an extranodal marginal zone B cell lymphoma. Lymphoepithelial lesions were absent, but were found in a clinically silent gastric lymphoma discovered four weeks later during staging investigations; this gastric lymphoma was negative for Helicobacter pylori by breath test and molecular biological analysis. Sequencing of the clonal immunoglobulin heavy chain gene in both tumours indicated the same precursor cell, of follicular or post follicular origin. In synopsis, the data suggested that this was a case of primary lymphoma of the bladder with involvement of the stomach. The application of a chromosome 3 specific alpha satellite probe revealed trisomy 3. A tumour with these characteristics arising as a lymphoma of the bladder with a metachronous involvement of the gastric mucosa has not been described previously.

Treatment outcome of mucosa-associated lymphoid tissue/marginal zone non-Hodgkin's lymphoma

PURPOSE

To evaluate the treatment outcome in patients with mucosa-associated lymphoid tissue (MALT)/marginal zone (MZ) non-Hodgkin's lymphoma (NHL).

MATERIALS AND METHODS

Between 1986 and 2000, 66 patients with clinical stage (CS) I-IV MALT/MZ NHL were treated; these comprise the study population. The progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier technique. Forty-five patients (68%) had CS I-II and 21 (32%) had CS III-IV disease. Twenty-nine of the 45 CS I-II patients received radiation therapy (RT) alone, and 6 patients had surgery and RT. The median RT dose was 3350 cGy. Among the 21 CS III-IV patients, treatment included chemotherapy alone (15), chemotherapy + RT (3), surgery (1), surgery + chemotherapy (1), and RT alone (1). Median follow-up was 48 months.

RESULTS

All 35 early-stage and all 4 advanced-stage patients who received RT as part of initial treatment achieved local control. Among the 63 evaluable patients, the 5-year OS and PFS were 90 and 57%, respectively. The 5-year OS was 93% and PFS was 75% among CS I-II patients; the corresponding estimates in CS III-IV patients were 83% and 14%, respectively.

CONCLUSION

Modest doses of RT provide excellent local control in patients with MALT/MZ NHL. The poor PFS in advanced-stage patients suggests the need to develop alternative systemic treatment strategies for this disease.

Disappearance of a mucosa-associated lymphoid tissue (MALT) lymphoma of the urinary bladder after treatment for Helicobacter pylori

A59-yr old man presented with macroscopic hematuria. A non-Hodgkin's lymphoma of the MALT type of the urinary bladder, stage I A-E, was diagnosed. Radiotherapy was advised, but the patient refused this kind of treatment. Because of the known relationship of a gastric MALT lymphoma and Helicobacter pylori, the patient was treated with HP eradication therapy. Afterwards the lymphoma disappeared. The patient is 3 yr later in a persistent complete remission. This is the first known case of the disappearance of a MALT lymphoma of the urinary bladder after treatment with HP eradication therapy.

MALT-type primary lymphoma of the urinary bladder: clinicopathological study of 2 cases and review of the literature

Primary lymphoma of the bladder is a rare non-epithelial bladder tumour. It is usually non-Hodgkin's lymphoma with mucosa-associated lymphoid tissue (MALT) lymphoma being its predominant subtype. Most of the literature has been limited to individual sporadic case reports. We present 2 cases of the MALT-type primary lymphoma of the urinary bladder which were treated in our unit. Both patients were females with a history of recurrent urinary tract infections. They were treated successfully with chemotherapy alone. We also present a review of the literature emphasising the clinical presentation, the morphological and immunophenotypic features and the various treatment modalities of this rarely seen bladder pathology.

Extranodal marginal zone B-cell lymphoma of malt type involving the cavernous sinus

Mucosa-associated lymphoid tissue (MALT) lymphomas are low-grade B-cell neoplasms that occur in a variety of extranodal sites. Only rarely has this entity been discovered as a primary tumor involving the dura of the cavernous sinus. We report the case of a 46 year old woman who presented with a mass involving the cavernous sinus that was originally diagnosed as a meningioma by MRI. However, at surgery the mass was found to be an extranodal marginal zone B-cell lymphoma of the MALT type. The patient underwent partial excision of the lesion followed by radiation. There are only seven other cases of marginal zone B-cell lymphoma involving the intracranial dura reported in the literature. These patients were females who presented with intracranial lesions thought to be consistent with meningioma by preoperative radiographic imaging. MALT lymphomas of the dura, as their counterparts in other organs, appear to have favorable clinical outcomes and excellent long-term prognoses with local therapy alone.

Primary lymphoma of the bladder: a report of three cases

BACKGROUND

Primary lymphoma of the bladder is rare and its management is an evolving field.

AIMS

To highlight primary lymphoma of the bladder as a possible diagnosis in cases of bladder neoplasm and to illustrate the currently favoured management options.

METHODS

Three cases of primary bladder lymphoma are reported and management is reviewed.

RESULTS

Each of the three cases was managed differently with each management approach yielding a favourable outcome.

CONCLUSION

Chemotherapy combined, if necessary, with surgery or radiation therapy, should be the standard of care, depending on the full histological diagnosis.

Primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type arising in the urinary bladder: report of 4 cases with molecular genetic analysis

CONTEXT

Primary lymphoma of the urinary bladder is rare. Only 84 cases have been reported in the English literature to date, and none of these cases has had molecular confirmation of clonal immunoglobulin gene rearrangement.

OBJECTIVES

To review all cases with primary urinary bladder lymphoma in our records, to classify them using the REAL classification, to confirm their immunophenotype and genotype, and to determine their outcome.

DESIGN

We identified 4 cases of primary urinary bladder lymphoma in our medical records from a 30-year period. Immunohistochemical detection of immunoglobulin light chains and molecular analysis of immunoglobulin heavy-chain genes using the polymerase chain reaction were performed on paraffin-embedded material.

RESULTS

All patients were older than 60 years. The male-female ratio was 1:3. All patients had a history of chronic cystitis. Histologic features of mucosa-associated lymphoid tissue lymphoma with centrocyte-like cells, plasmacytoid B cells, or both were observed in all cases. Monoclonality of B cells was demonstrated by immunohistochemistry, polymerase chain reaction, or both methods in every case. All patients presented with stage IAE disease, were treated with radiotherapy alone, and have been in continuous complete remission for 2 to 13 years.

CONCLUSIONS

Primary bladder lymphomas are usually of low-grade mucosa-associated lymphoid tissue type. They are more common in females and are associated with a history of chronic cystitis. Lymphoepithelial lesions are seen only in association with areas of cystitis glandularis. B-cell clonality is readily demonstrable by immunohistochemistry and/or polymerase chain reaction analysis. Local radiotherapy appears to confer long-term control.

Malignant lymphoma of the urinary bladder: a clinicopathological study of 11 cases

AIM

To report the clinical and histological features and outcome of primary and secondary malignant lymphomas of the urinary bladder.

METHODS

Eleven cases of malignant lymphoma of the urinary bladder were obtained from the registry of cases at St Bartholomews and the Royal London Hospitals. The lymphomas were classified on the basis of their morphology and immunophenotype, and the clinical records were reviewed.

RESULTS

There were six primary lymphomas: three extranodal marginal zone lymphomas of mucosa associated lymphoid tissue (MALT) type and three diffuse large B cell lymphomas. Of the five secondary cases, four were diffuse large B cell lymphomas, one secondary to a systemic follicular follicle centre lymphoma, and one nodular sclerosis Hodgkins disease. Four patients with secondary lymphoma for whom follow up was available had died of disease within 13 months of diagnosis. Primary lymphomas followed a more indolent course. In one case, there was evidence of transformation from low grade MALT-type to diffuse large B cell lymphoma. The most common presenting symptom was haematuria. Cystoscopic appearances were of solid, sometimes necrotic tumours resembling transitional cell carcinoma, and in one case the tumours were multiple. These cases represented 0.2% of all bladder neoplasms.

CONCLUSIONS

Diffuse large B cell lymphoma and MALT-type lymphoma are the most common primary malignant lymphomas of the bladder. Lymphoepithelial lesions in MALT-type lymphoma involve transitional epithelium, and their presence in high grade lymphoma suggests a primary origin owing to transformation of low grade MALT-type lymphoma. Primary and secondary diffuse large B cell lymphomas of the bladder are histologically similar, but the prognosis of the former is favourable.

Low-grade MALT lymphoma of the stomach: a review of treatment options

PURPOSE

Low-grade mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach (MLS) is often associated with the presence of Helicobacter pylori (H. pylori) bacteria. Eradication of the infection with antibiotic therapy may result in regression of the lymphoma. But when antibiotic treatment fails to reverse the malignant process or if H. pylori is absent, other treatment options should be considered. Because MLS is often confined to the stomach and regional lymph nodes, it is potentially curable with local therapy. Endoscopy and improved imaging, with endoscopic ultrasound (EUS) and computerized tomography (CT), have reduced the prior dependence on surgery for diagnosis and staging of gastric lymphomas.

METHODS AND RESULTS

This review details the advances in the diagnosis, classification, and imaging of MLS. We also describe the experience that supports the use of radiation therapy as the preferred treatment of MLS in patients who have not responded to antibiotic therapy or have not had evidence for H. pylori infection.

CONCLUSIONS

Radiation therapy for MLS is not only effective and safe, but offers the significant advantage of low morbidity and gastric function preservation.

Low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of thymus

This report describes a low-grade B-cell lymphoma of mucosa associated lymphoid tissue (MALT) involving the thymus of a 63-year-old woman with features suggestive of a connective tissue disease. Sections of the thymic lesion and of a lung biopsy performed at the same operation were examined histologically and by immunohistochemistry using the monoclonal antibodies CD45, CD20, CD79a, CD3, CD45RO, and AE1/AE3. Polymerase chain reaction (PCR) for immunoglobulin heavy chain gene rearrangement was also performed. The dense infiltrate of small lymphoid cells intimately admixed with ramifying epithelial elements, some of which had undergone cystic change, closely resembled a thymoma. The lymphoid infiltrate comprised centrocyte-like cells, small lymphocytes, plasma cells, and blasts. Most of the lymphoid cells were immunoreactive with the B-cell markers CD20 and CD79a, and PCR showed clonal immunoglobulin heavy chain gene rearrangement. The lung biopsy showed dense infiltration by small lymphoid cells, morphologically suggestive of lymphoid interstitial pneumonia. However, PCR showed a weak band in the amplification for immunoglobulin heavy chain gene rearrangement, identical to that within the thymus and suggesting either recirculation of cells to accumulated MALT or subhistological lymphoma. MALT lymphoma may rarely involve the thymus, and pathologists should be aware of this to avoid misdiagnosis as a thymoma. Immunohistochemical and/or molecular studies are of value in this regard. MALT lymphomas of the thymus, common with those arising in other organs, may develop in the setting of a connective tissue disease.

Primary low-grade lymphoma of mucosa-associated lymphoid tissue of the urinary bladder: a case report with special reference to the use of ancillary diagnostic studies

We report a case of primary low-grade B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type of the urinary bladder. The patient, a 77-year-old woman, presented with a sense of urinary retention. An intravenous pyelogram and cystoscopy revealed a wide-based submucosal mass measuring 3 cm in the left wall of the urinary bladder. Histological findings of the tissue obtained by transurethral resection (TUR) showed a dense, monomorphic atypical lymphoid (centrocyte-like) infiltrate with reactive lymph follicles in the subepithelial tissue. Monocytoid and plasmacytoid features were readily evident in a population of these cells. Lymphoepithelial lesions involving the urothelium were also noticed in some areas. These features were strongly suggestive of primary low-grade lymphoma of the MALT type. The diagnosis was confirmed by immunohistochemical and flow cytometric studies, both of which showed a clear immunoglobulin restriction to lambda light chain and also by polymerase chain reaction-based assay using a formalin-fixed paraffin-embedded TUR tissue sample, which showed a clonal Ig heavy-chain gene rearrangement. Clinical staging procedures revealed that the tumor was localized in the urinary bladder. The patient has not received chemotherapy and is alive and well with no evidence of recurrence, 3 years after TUR. This case demonstrates that these ancillary tests are worth performing for confirmation of B-cell clonality in TUR tissue samples showing dense B-lymphocytic infiltration.

Urinary bladder. Mimics of neoplasia and new pathologic entities

A wide range of epithelial and mesenchymal pseudoneoplastic disorders of the urinary bladder may clinically and pathologically mimic a malignant neoplasm. These lesions usually require a tissue biopsy for definitive diagnosis. It is important to be aware of these lesions and their spectrum of morphologic appearances to avoid overdiagnosis and inappropriate aggressive therapy.

Lymphoma at uncommon sites

Lymphoma can often present in unusual situations. This article provides a comprehensive review of the literature in which both non-Hodgkin's lymphoma and Hodgkin's disease are discussed.

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 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.