F18 FDG positron emission tomography revelation of primary testicular lymphoma with concurrent multiple extra nodal involvement
A 48-year-old male presented with progressive enlargement of right testis of 3 weeks duration. There was associated dragging sensation in the right testicular region and in the lower abdomen. No associated urinary symptoms, fever or weight loss. No medical history of diabetes or hypertension and no family history of any solid or hematological cancers. Physical examination revealed a large right testicular swelling of 10 cm × 8 cm size, firm in consistency with mild pain on palpation, testicular sensation was preserved. There was no accompanying palpable inguinal adenopathy. Contra lateral testis was normal in size and unremarkable on physical examination. Systemic examination was unremarkable. Initial laboratory data revealed mild normocytic normochromic anemia with hemoglobin of 10.2 g/dL, platelet count of 2.9 lakhs/cu mm, lactate dehydrogenase of 369 U/L. Chest radiograph was normal. Patient underwent a computed tomography (CT) scan of the abdomen and pelvis, which revealed an enlarged right testis of uniform density with no retroperitoneal lymphadenopathy and right adrenal was mildly enlarged. FNAC of right testis showed provisional possibility of poorly differentiated carcinoma. Positron emission tomography/CT (PET/CT) was performed for initial assessment and staging, which revealed a markedly enlarged right testis showing intense metabolic activity with standardized uptake value (SUV) max of 35.5. Normal sized left testis also showed intense Fluoro deoxy glucose uptake with SUV max of 15.9. Hyper metabolic activity was also noted in loco regional small volume inguinal nodes bilaterally with SUV max of 15.5. There were additional areas of hyper metabolic activity noted in extra testicular extra nodal sites such as, contra lateral testis, adrenals, and small bowel loops []. Metabolically active area of a CT based hypo dense area encircling the superior vena cava right atrial junction []. Hyper metabolic nodule was noted in the subcutaneous planes of right thigh []. Patient underwent a right inguinal orchidectomy. Histopathology showed enlarged testis measuring 9.5 cm × 6 cm × 6 cm. Cut section was fleshy and grey white. Normal testicular tissue was not evident. Microscopy showed entrapped seminiferous tubules in sheets of monomorphic dyscohesive cells. These cells are large and show vesicular pleomorphic nuclei, clumped chromatin, small nucleoli, and a minimal amount of cytoplasm. Mitosis is increased. Surgical margin of the spermatic cord was free of tumor. Tunica was not infiltrated with tumor []. Immuno histo chemistry was carried out for further typing which showed diffuse membranous CD-20 positivity with increased Ki67 index of 85-90%. CD10 was negative. Findings were consistent with primary testicular diffuse large B cell lymphoma, Post surgery chemotherapy with Cyclophosphamide, Hydroxydaunorubicin, Oncovin (Vincristine), Prednisolone regimen was followed by an interim PET after four cycles of chemotherapy, which showed complete morphological and metabolic regression of all the lesions [].