18F-PSMA-1007 PET/CT uptake in multiple angiolipomas caused by PSMA expression in capillaries: a case report

Abstract

Prostate specific membrane antigen (PSMA) is a transmembrane glycoprotein that was originally cloned in the membrane of prostate gland epithelial cells. It has been confirmed to be highly expressed in prostate cancer cells, and in some non-prostatic tissues, including the brain and some benign lesions. PSMAbased imaging has been extensively used for the assessment of prostate carcinoma. The high uptake of PSMA imaging in these non-prostate cancer lesions may lead to some misdiagnosis. It is of important clinical significance to explore the possible causes of high PSMA uptake in these lesions. Here, we present a case of a 77-year-old man with prostate carcinoma who underwent a whole-body 18 F-PSMA-1007 positron emission tomography/computed tomography (PET/CT) scan for staging. The results of the scan showed intense tracer uptake in both the prostatic bed and in multiple subcutaneous lesions. The subcutaneous lesions were later found to be angiolipomas by histopathological examination. Immunohistochemistry demonstrated strong positive cytoplasmic PSMA staining in lesional prostate cancer cells in prostate carcinoma, and mildto-moderate positive cytoplasmic capillary PSMA staining in angiolipoma fatty density nodules. Our case report therefore demonstrated that 18 F-PSMA-1007 PET/CT uptake in multiple angiolipomas was caused by PSMA expression in capillaries, and further knowledge of PSMA expression in benign lesions may be critical to minimize false-positive findings with 18 F-PSMA-1007 PET/CT imaging.

False Positive Findings of [18F]PSMA-1007 PET/CT in Patients After Radical Prostatectomy with Undetectable Serum PSA Levels

“…Histologic validation of the findings was available however, in only 87 cases (13.3%) and composite reference standard (i.e., PSA decline after targeted therapy) in 217 cases (33.2%). The current work, as do some of the aforementioned studies (8,11,23), suggest that at least some of these foci were not PC metastases and we believe that the information presented in the current study can potentially change the way PSMA-PET is interpreted. Additionally, different populations (patients with rising PSA after treatment in the study by Fendler et The limitations of the study are the small sample size and being single centered.…”

“…Skin uptake in multiple locations was noticed in two patients with no specific corresponding abnormality. Uptake of [ 18 F]PSMA-1007 was previously reported in several skin conditions including neurofibromatosis, melanoma and angiolipoma, mostly associated with PSMA expression in endothelial capillaries (22)(23)(24).…”

Comparison of 68Ga-PSMA PET/CT and multiparametric MRI for the detection of low- and intermediate-risk prostate cancer

“…One hour before scanning, all patients were given an intravenous injection of 68 Ga-PSMA. The acquisition parameters of the PET/CT were described in previous literature [ 19 ]. PET/CT imaging was independently evaluated and reported the presence of suspicious lesions by two double-trained board-certified nuclear medicine physicians who were blinded to the mpMRI and pathological results.…”

Multiple angiolipoma of the hand, back, and abdomen; a case report

“…Angiolipoma is an uncommon benign subtype of lipoma, mainly composed of a mixture of proliferating blood vessels and mature adipose tissues, in addition, fibrin thrombi are commonly observed [7] . It was first reported in 1912 by Bowen and associates, and in 1960, Howard et al described angiolipoma as a clinically and histologically different variant of lipoma, as the degree of vascularity of angiolipoma was much higher than that of a normal lipoma [8] , [9] .…”