Metastatic onset of prostate carcinoma: A clinical and pathological challenge

Prostate cancer is the second most common cancer, following lung cancer, and the fifth leading cause of cancer death in men worldwide. The onset of the disease, characterized by symptoms or changes caused by distant metastases, is rare and poses a challenge for clinicians and pathologists. We aimed to present a series of prostate carcinoma (PC) with unusual, histologically confirmed distant metastases (pM1) at the time of diagnosis, which raised suspicions of other types or origins of the primary tumor.

Patients diagnosed with PC and distant metastases within a five-year timeframe (2017-2022) were extracted from the hospital database. The following data were collected: patient's age, imaging data, serum PSA level, and histopathological evaluation results. Patients with unusual distant metastases were selected and analyzed.

We identified 10 patients in whom the diagnosis of PC was established following histopathological examination of tissue taken from distant metastatic sites (pM1). In three patients, the location of distant metastases was unusual: retroperitoneal, cranial/dural/epicranial and supradiaphragmatic lymph nodes which posed diagnostic challenges. Establishing the prostate origin of the tumor relied on immunohistochemical (IHC) investigation guided by clinical-imaging information.

A metastasis of PC may rarely present as a cranial/dural tumor, retroperitoneal, or supradiaphragmatic lymphadenopathies in a man over the age of 50, but it should be taken into consideration. In the absence of correlated clinical, imaging, and histopathological/IHC data, diagnosing distant metastasis from PC is difficult, especially considering its potentially confusing IHC profile.