The John Hunter Hospital in Newcastle has reported an extremely rare case of primary prostatic lymphoma in a young man with urinary symptoms.

The case, published in the Journal of Surgical Case Reports [link here], is a reminder to clinicians to consider prostate lymphoma when assessing patients with urinary symptoms given that early diagnosis is of paramount importance to patient outcomes.

The patient was a 25-year-old man with a 6-month history of lower urinary tract symptoms, including frequency, nocturia, poor urinary flow, dysuria, urgency and occasional urge incontinence.

Digital rectal examination showed a diffusely enlarged, irregular non-tender prostate suspicious for malignancy. Prostate-specific antigen was 0.53 µg/L.

Renal function tests revealed progressive worsening of previously normal eGFR down to 27 ml/min.

Initial renal tract ultrasound showed an enlarged prostate indenting into the bladder base; CT of the kidneys, ureters and bladder showed an irregularly enlarged prostate with bilateral hydroureteronephrosis.

MRI prostate revealed enlarged prostate with PIRADS 5 amorphous mass suspicious for carcinoma involving bilateral seminal vesicles and right vesicouretric bladder.

“FDG PET showed unusual distribution pattern of lymphoma involving the prostate with bilateral symmetrical renal, early pulmonary, and possibly right thyroid lobe involvement,” the case report said.

Histology following a transperinal prostate biopsy confirmed a diagnosis of diffuse large B cell lymphoma.

“3 months post R-CHOP chemotherapy showed complete metabolic response with no avid residual lymphoma,” the case report said.

The authors said primary prostate lymphoma was a relatively rare malignant tumour accounting for 0.09% of prostate neoplasms and only 0.1% of newly diagnosed lymphomas.

It was more typically observed in older men.

“Various subtypes of NHL of the prostate have been reported, including but not limited to follicular lymphomas, Burkitt lymphomas, mantle cell lymphomas, and mucosa-associated lymphoid tissue lymphomas; however, diffuse large B cell lymphoma remains the most common.”

They said patient presentation was typically for non-specific urinary symptoms rather than specific lymphoma B-symptoms such as fever, night sweats, and weight loss.

“The final diagnosis is usually delayed due to the non-specific clinical symptoms at presentation and achieved by pathological and immunohistochemical examinations of samples obtained by transperineal prostate biopsy or transurethral resection of prostate.”

Unfortunately, the prognosis of prostate lymphoma is poor with one case series reporting 1-, 2-, 5-year survival rates of 64%, 50%, and 33% respectively.

They said R-CHOP with or without radiotherapy is the treatment of choice.

“Surgical intervention with radical prostatectomy or TURP does not improve survival rate but it can be of diagnostic value if needle biopsy is equivocal.”

“Radiotherapy is rarely given alone, but it can quickly relieve symptoms of acute urinary tract obstruction and reduces the rate of local recurrence.”

The case report was authored by Dr Mohammed Ali Alhamadani, Dr Aleksandr Pecherkin and Dr Terrence Doyle from the Department of Urology, John Hunter Hospital.