CASE 8954 Published on 10.02.2011

Testicular lymphoma in HIV: ultrasound and MRI findings

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Tonolini Massimo, MD.
Radiology Department, "Luigi Sacco" Hospital, Milan (Italy)

Patient

35 years, male

Categories
Area of Interest Genital / Reproductive system male, Abdomen ; Imaging Technique Ultrasound, MR, CT
Clinical History
Scrotal swelling in 35-years-old patient, with a 4-year history of HCV-HIV coinfection undergoing highly active antiretroviral treatment. Firm, nontender right testicular enlargement at palpation.
Abnormal laboratory tests including 249/mmc CD4+ count (normal range 500…1500/mmc), raised LDH (805 U/l); blood cells and tumour markers (CEA, alpha-fetoprotein and beta-HCG) within normal limits.
Imaging Findings
On further questioning, the patient admitted persistent low-grade fever, vomiting, progressive weakness and weight loss (about 5 kg) during the last month. Report of a multiphasic CT performed 1 year earlier at another Hospital excluded focal liver lesions and abdominal lymphadenopathies.
Scrotal ultrasound revealed upper limits-sized testes with a roundish 2-cm hypoechoic lesion and some associated hydrocele on the right, two tiny similar lesions in the contralateral testis and absent epidydimal involvement.
Contrast-enhanced MRI was requested to further investigate these uncommon sonographic findings, particularly to assess lesions’ vascularization and to depict more precisely the local anatomy in view of a possible surgical or bioptic approach. MRI confirmed bilateral involvement showing three T2-hypointense intratesticular lesions, isointense on unenhanced T1-weighted images with a strong homogeneous contrast enhancement after intravenous gadolinium.
Subsequently, total body CT staging revealed the association of innumerable liver and renal hypovascular lesions. Percutaneous biopsy of a liver mass disclosed high-grade large B-cell CD20-positive non-Hodgkin lymphoma (Ki67>90%). Cerebrospinal fluid analysis and bone marrow biopsy were negative, disease stage was assessed as IV B due to presence of systemic symptoms and extranodal (hepatic, renal and testicular) involvement.
The patient died suddenly due to intestinal perforation after 3 cycles of fractionated R-CHOP chemotherapy.
Discussion
Although lymphoma represent 5%-9% of all testicular neoplasms, only 1% of lymphomas involve the testis, as the initial manifestation of generalised disease or more commonly later during its course, very rarely as the primary and only site.
Lymphoma is the most common testicular malignancy in older men, but is uncommon under the age of 50 with the exception of immunosuppressed patients.
At pathology, most testicular lymphomas are high-grade, diffuse large B-cell lymphomas with a tendency for widespread dissemination to the central nervous system, Waldeyer ring, skin, sometimes the lungs and visceral organs. Lymphoma may be locally aggressive with invasion of the epididymis, spermatic cord or scrotal skin.
These tumours are usually diagnosed in patients with a painless testicular enlargement developing over a span of weeks to months, and a firm mass at palpation. Systemic symptoms including weight loss, night sweats, anorexia, fever, and weakness may be associated in 25% of cases.
The mainstay treatment includes systemic chemotherapy and orchiectomy. The disease is highly aggressive and extranodal dissemination portends a poor prognosis with a median survival of 13 months and 5-year disease-free survival rate of 12%–35%.
Ultrasound with a high-frequency transducer, always the initial imaging modality of choice for scrotal enlargement or palpable abnormality, depicts either homogeneously hypoechoic enlarged testes in cases of diffuse infiltration or variable-sized hypoechoic lesions, the largest ones with possible visualisation of intralesional flow signals at colour/power Doppler.
US is nearly 100% sensitive for detection of testicular tumours, but its findings are usually non-specific and differential diagnosis includes a wide range of conditions.
The radiologist should keep in mind that lymphoma is the most common bilateral (up to 38% of cases) testicular neoplasm, with metachronous involvement being more common. Furthermore, intratesticular masses are more likely to be malignant while the majority of extratesticular masses are benign, but lymphoma sometimes infiltrates the epididymis which then appears enlarged and hypoechoic.
MRI is an ideal second-line, problem-solving modality for inconclusive US findings and complex cases of scrotal disease. The normal testis has homogeneous T1-intermediate and T2-elevated (slightly less than that of fluid) signal intensity, with clear depiction of the tunica albuginea as a thin low-signal band surrounding the testis in both pulse sequences.
MRI provides precise tissue assessment with identification of haemorrhage, fibrosis, cysts and fluid, necrosis, thus ruling out most non-neoplastic tumorlike testicular conditions; allows confident characterisation of scrotal masses location as intra- or extratesticular narrowing the differential diagnosis; may demonstrate greater extent of disease (including bilaterality) relative to that shown with sonography; and helps preoperative planning with demonstration of infiltration of the tunica albuginea, tunica vaginalis, epididymis and scrotal wall.
Solid tumours are usually isointense relative to normal testicular tissue on T1- weighted and clearly hypointense on T2-weighted images. Heterogeneity may be due to intralesional bleeding, cystic components, necrosis, fibrosis and calcifications. As in this case, MRI may be completed with a gadolinium-enhanced acquisition (usually with a fat-saturated T1-weighted spoiled gradient-echo sequence) that allows assessment of lesion vascularity, which may furthermore help in characterisation.
Differential Diagnosis List
Testicular non-Hodgkin lymphoma
Orchitis
Tuberculosis
Sarcoidosis
Testicular germ-cell tumour
Seminoma
Leukemia
Metastases
Segmental testicular infarct
Final Diagnosis
Testicular non-Hodgkin lymphoma
Case information
URL: https://www.eurorad.org/case/8954
DOI: 10.1594/EURORAD/CASE.8954
ISSN: 1563-4086