PMC5346921_01
Computed tomography scan of the abdomen/pelvis showing cecal mass (a) and enlarged prostate (b). The scan shows a prostatic space-occupying lesion with unclear rectal boundaries and an absence of the bladder seminal vesicle angle.
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A computerized tomography scan of the neck, chest, abdomen, and pelvis revealed diffuse urinary bladder wall thickening and an enlarged prostate, as well as a 2.4-cm soft tissue mass within the cecum involving the ileocecal valve, and no evidence of obstruction (Fig. 1).
Positron emission tomography scan showing increased uptake in the prostate prior to therapy (a) and decreased metabolic activity following treatment (b) and 12 months after therapy (c).
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A positron emission tomography (PET) scan showed significantly increased metabolic activity in the cecum and prostate gland (Fig. 2a) and mild 18F-fluorodeoxyglucose avidity within the distal esophagus. Posttreatment PET scans (Fig. 2b, c) showed complete remission, and the patient has been disease free for the past 2 years with continuing surveillance in our clinic.
A The prostate transurethral resection specimen was remarkable for a diffuse infiltrate of large atypical lymphoid cells and background small mature lymphocytes (a). The large atypical cells consisted of a mixture of immunoblast-like and centroblast-like cells that replaced the normal prostate parenchyma (b). (Hematoxylin and eosin at 200x magnification.) B Immunohistochemical staining of the large atypical lymphoid cells showed diffuse positivity with CD20 (a) and BCL-6 (b). Overall, the immunohistochemical staining patterns were consistent with a diagnosis of diffuse large B-cell lymphoma. (Both images at 200x magnification.)
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The large atypical cells were pleomorphic with irregular nuclear contours and occasional cleaved nuclei, and prominent nucleoli were also identified (Fig. 3A). The atypical cells expressed CD20, BCL-6 (Fig. 3B), and BCL-2 (variable positivity), while lacking expression of CD5, CD10, AE1/3, EMA, P501S, and PAP. The Ki-67 proliferation index accounted for approximately 30-40% of the atypical lymphocyte population. The overall morphology and immunohistochemistry profile was noted to be diagnostic of diffuse large B-cell lymphoma (DLBCL) (Fig. 3).