BackgroundCurrent guidelines highlight the importance of accurate staging in the management and prognostication of high risk primary prostate cancer. Conventional radiologic imaging techniques are insufficient to reliably detect lymph node metastases in prostate cancer. Despite promising results, there is limited published data on the diagnostic accuracy of PSMA PET-CT to assess local nodal metastases prior to radical prostatectomy.This study aims to assess the diagnostic efficacy of 68Ga PSMA PET-CT in local lymph node staging of high risk primary prostate cancer when compared to histopathological findings following radical prostatectomy with pelvic lymph node dissection.MethodsWe retrospectively analysed consecutive patients with high risk primary prostate cancer referred by urologists for primary staging PSMA PET-CT using a 68Ga-labeled PSMA ligand, Glu-NH-CO-NHLys-(Ahx)-[HBEDD-CC], from October 2015 to October 2017. The scans of patients who underwent radical prostatectomy with pelvic lymph node dissection were interpreted by the consensus reading of two experienced nuclear medicine physicians blinded to clinical and histopathological data. The contemporaneous records of the referring urologists were retrospectively reviewed for noteworthy unexpected PET findings that altered their personal preference for surgical management.ResultsSeventy-one patients were recruited and analysed. PSMA PET-CT showed findings compatible with local disease in 47 patients (66.2%), lymph node metastases in 10 patients (14.1%) and distant metastases in 14 patients (19.7%). Twenty-eight patients (twenty-seven of whom had local disease only) underwent surgery yielding 214 lymph nodes, all of which were negative on histopathological analysis. On a node-based analysis, 213 of 214 lymph nodes were accurately identified as negative for disease with a negative predictive value of 100%. 11 patients had unexpected PET findings contemporaneously documented by urologists to alter their preference for surgical management.ConclusionsPSMA PET-CT appears to have a high negative predictive value for local lymph node metastases in high risk primary prostate cancer when compared to histopathological findings following radical prostatectomy with pelvic lymph node dissection.

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Lipomas are the commonest benign mesenchymal tumours, commonly seen as a subcutaneous lump. However, intermuscular lipomas are uncommon and can remain asymptomatic until they attain larger sizes. We discuss a rare case of a large symptomatic intermuscular lipoma in a 34-year-old woman who presented with acute on chronic groin pain. Clinical examination findings were consistent with an incarcerated inguinal hernia and imaging confirmed a large intermuscular lipoma of the anterior abdominal wall, the tip of which herniated into the inguinal canal. She underwent open primary repair of the hernia along with excision of the lipoma. An intermuscular lipoma presenting as an incarcerated inguinal hernia at the first instance is an uncommon finding. Due to lack of obvious clinical findings, uncomplicated intermuscular lipomas can be challenging to diagnose until they become symptomatic, and a high degree of suspicion in patients reporting atypical abdominal and groin pain, or abdominal wall fullness is required.