Case Report: 18F-PSMA PET/CT May Improve the Clinical Management of Penile Metastases From Prostate Cancer

Metastases from prostate cancer (PCa) to the penis are extremely rare, and few case reports exist in the literature. Because most patients usually present with multiple distant metastases at diagnosis, the prognosis is very poor. With the wide application of prostate-specific membrane antigen (PSMA) PET/CT, penile metastases may be detected at an early stage. Thus, questions regarding whether early diagnosis and precise treatment will equate to a survival advantage have recently been raised. In the present study, we reported 3 cases of penile metastasis from castration-resistant PCa. Moreover, a patient with asymptomatic penile metastases was diagnosed by 18F-PSMA PET/CT followed by lesion biopsy, and the prognosis was very well, despite with an aggressive pathological feature and low treatment intensity. In addition, we performed a literature review and found 62.5% of asymptomatic penile metastases were diagnosed by PSMA PET/CT in past seven years. Thus, we believe that PSMA PET/CT may detect more asymptomatic penile metastases in future, which led to early diagnosis, treatment and survival advantage.

PSMA-PET/CT-avid metastatic prostate cancer to the penis

Penile metastases from prostate cancer (PC) are rarely reported in the literature. Most commonly diagnosed due to presentation with malignant priapism and other urinary symptoms or from findings on clinical examination, prognosis has been reported to be poor. The authors outline a case of penile metastasis from advanced PC. Initially treated with neoadjuvant androgen deprivation therapy for locally advanced PC, this patient displayed upfront castrate resistance, and subsequent prostate-specific membrane antigen positron emission tomography revealed penile metastatic deposits. The patient was treated with external beam radiotherapy, and worsening urethral stricture disease resulted in the placement of a suprapubic catheter.

Thrombosis of the dorsal vein of the penis as first clinical presentation of pancreatic cancer metastatic to the penis

Introduction: Though metastatic disease is a common presentation of pancreatic adenocarcinoma, localization to the penis is an extremely rare event despite its abundant vascularization. Primary cancers responsible for penile metastases usually occur in prostate and rectum and are often associated with disseminated malignancy and poor prognosis. Case description: A 66-year-old man was diagnosed with adenocarcinoma of the tail of the pancreas after the onset of thrombosis of the dorsal vein of the penis; pubis ultrasound and total body computed tomography scan were negative for metastases at other sites. The patient was submitted to distal pancreatectomy with splenectomy for a pT3 N1 G4 pancreatic ductal adenocarcinoma. Three weeks after discharge, the patient returned to the outpatient clinic complaining of a painful permanent turgidity of the penis shaft. Ultrasound revealed a complete replacement of the cavernosal bodies by multiple nodular masses and a penile biopsy confirmed metastases from the primary pancreatic cancer. The patient started chemotherapy with NAB-paclitaxel and gemcitabine, with excellent control of symptoms. However, the disease progressed to bone and liver and the patient died 9 months after surgery. Conclusions: Penile localization is an extremely rare event and a standard of care has not been elaborated. Treatments are palliative and mainly aimed at pain relief and can comprise chemotherapy, radiotherapy, and surgery. Identification of venous thrombosis as an early sign of involvement could potentially offer patients an earlier diagnosis and a better treatment option.