Penile secondary lesions: a rare entity detected by PET/CT

Tima Davidson,Eddie Fridman,Zohar Dotan,Yogev Giladi,Barak Rosenzweig,Raya Leibowitz,Jennifer Ben Shimol,Liran Domachevsky

doi:10.1038/s41598-021-85300-8

Abstract

While penile metastases are rare, PET/CT has facilitated their detection. We aimed to describe penile secondary lesions (PSL) identified by PET/CT. We reviewed 18F-FDG and Ga68-PSMA PET/CT records performed in a single center during May 2012-March 2020, for PSL. Of 16,774 18F-FDG and 1,963 Ga68-PSMA-PET scans, PSL were found in 24(0.13%) men with a mean age of 74. PSMA detected PSL in 12 with prostate cancer; FDG identified PSL in 4 with lymphoma, 3 with colorectal cancer, 2 with lung cancer, and one each with bladder cancer, pelvic sarcoma, and leukemia. Mean SUVmax of PSL was 7.9 ± 4.2 with focal uptake in 13(54%). Mean lesion size was 16.5 ± 6.8 mm; 8 at the penile root, 4 along the shaft, and 1 at the glans. CT detected loss of the penile texture in 15(63%). PSL were observed only during relapse or follow-up of disseminated disease. Among those with prostate cancer, PSA varied widely. Fifteen (62.5%) died, at a mean 13.3 ± 15.9 months following PSL demonstration, nine had non-prostate malignancies. PET/CT identified and characterized PSL in a fraction of cancer patients, most commonly those with prostate cancer. PSL universally surfaced in advanced disease, and signaled high mortality, especially in non-prostate cancers.

Highlights

While penile metastases are rare, PET/CT has facilitated their detection
We found evidence of penile secondary lesions (PSL) in 0.13% of all male patients who had PET/CT scans performed for evaluation of known or suspected oncological diseases, and in 0.61% of those with suspected or confirmed prostate cancer who had undergone Ga 68-PSMA studies
In malignancies with avidity for FDG and PSMA, PET/CT enables the detection of PSL

Summary

Introduction

We aimed to describe penile secondary lesions (PSL) identified by PET/CT. Of 16,774 18F-FDG and 1,963 Ga68-PSMA-PET scans, PSL were found in 24(0.13%) men with a mean age of 74. PSL were observed only during relapse or follow-up of disseminated disease Among those with prostate cancer, PSA varied widely. Fifteen (62.5%) died, at a mean 13.3 ± 15.9 months following PSL demonstration, nine had non-prostate malignancies. PET/CT identified and characterized PSL in a fraction of cancer patients, most commonly those with prostate cancer. Penile secondary lesions (PSL) appear infrequently among cancer patients; several hundred cases have been reported since Eberth originally described them in 1 8701–5. The increasing use of PET/CT to stage malignancies, by means of 18F-FDG (18-fluorodeoxyglucose) and Ga 68-PSMA (gallium 68-labeled prostate specific membrane antigen), facilitates the detection of P SL13–17. Our objective was to characterize the PET/CT features of PSL in cancer patients at a large tertiary institution

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Discussion

Conclusion