We report a rare case of a 59-year-old male with a history of metastatic prostate cancer presenting with acute onset dyspnea due to extensive bilateral pleural effusions. This case highlights the rarity of metastatic prostate cancer with pleural involvement and underscores the importance of accurate diagnosis using cytopathology and immunohistochemical staining.

Despite the significant advancements in prostate-specific antigen (PSA) screening and the diverse array of available treatments, prostate cancer (PCa) still significantly contributes to cancer-related illness. The most prevalent sites for metastases are bones, distant lymph nodes, and abdominal organs. Nevertheless, metastasis to the renal and retroperitoneal regions originating from prostate cancer constitutes an exceptionally uncommon clinical occurrence. Metastatic PCa commonly presents with elevated serum PSA levels, a hallmark of its diagnostic profile. However, there are instances where patients exhibit atypical metastatic patterns or maintain normal PSA levels. In the case under consideration, the patient exhibited a periureteral tumor with an indeterminate primary origin, subsequently confirmed to be metastatic prostate cancer. This case underscores the importance of recognizing the varied and sometimes elusive presentations of metastatic PCa. Despite its rarity, the occurrence of renal and retroperitoneal metastasis emphasizes the need for vigilance and a comprehensive understanding of the diverse manifestations of advanced PCa for timely and accurate diagnosis, which is paramount in optimizing patient care and outcomes.

Prostate cancer has an indolent progression course and commonly metastasizes to the vertebrae bone and regional lymph nodes. We report a patient with prostate cancer who has developed cutaneous metastases in multiple regions, including the right infraclavicular and abdominal area, as well as the left supraclavicular region. It presented as isolated, prominent nodules that were microscopically proven to be of prostate adenocarcinoma when biopsied. This rare presentation is a marker of an advanced disease course with a poor prognosis in castrate-resistant prostate cancer. Thorough clinical examination to rule out metastasis from the prostate and other dermatological conditions is paramount as well as ensuring early detection and optimizing patient outcomes.

Elevated prostate-specific antigen (PSA) levels are mostly suggestive of prostate cancer, but they are elevated in non-cancerous prostatic conditions as well. However, extreme levels of PSA as reported here have not been observed in cases other than prostatic cancer so far. Our patient had a significantly elevated PSA of 1,398 ng/mL in acute prostatitis. The purpose of this case report is to review the patient\'s atypical and rare presentation of extremely high PSA in acute prostatitis in the background of benign prostatic hyperplasia (BPH) and chronic prostatitis.

Despite the role of prostate-specific antigen (PSA) screening and the multitude of therapies available, prostate cancer (PCa) remains a leading cause of cancer-related morbidity and mortality. For many patients diagnosed with PCa, clinical and radiographic staging are critical components for management decisions. PCa staging with the use of imaging modalities such as MRI and bone scintigraphy is recommended in patients with newly diagnosed intermediate or high-risk PCa and in patients with biochemical recurrence; it is also recommended for monitoring the patient\'s response to treatment for diagnosed PCa. Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT), recently approved in 2021, is an imaging modality that has been shown to have a greater sensitivity, specificity, and negative likelihood ratio than conventional imaging modalities such as CT, bone scintigraphy, and MRI in prostate cancer staging. Despite the improvement in staging that PSMA-PET/CT can provide, our current report details a false-negative result in detecting a rare PCa metastasis to the peritoneum, which was found at the time of an attempted radical prostatectomy. Although the patient had a negative preoperative PSMA-PET/CT and was presumed to be non-metastatic, the prostatectomy was aborted because the patient was unexpectedly found to have peritoneal metastasis.

Metastatic prostate cancer is a common diagnosis with a protracted but terminal course. Gastrointestinal (GI) tract involvement is extremely rare, and reportedly portends a poor prognosis. It can present years after the initial prostate cancer diagnosis. Only fifteen cases of prostate cancer metastasis to the stomach have been reported in the literature. We report a case of a 72-year-old man with metastatic castration-resistant prostate cancer and extensive bony involvement. He presented a decade after the diagnosis of prostate cancer with signs of heartburn; a gastric biopsy was initially believed to represent primary gastric carcinoma, but subsequently a diagnosis of prostate cancer metastatic to the stomach was confirmed. This case highlights the importance of the provision of a pertinent clinical history and clinical differential diagnosis at the time of submission of surgical pathology specimens, as well as highlighting the need to have a low index of suspicion to pursue additional pathologic markers whenever a presumed second adenocarcinoma is noted in the context of a patient having a history of current or prior advanced-stage adenocarcinoma of another site. The correct diagnosis can shield the patient from the morbidity of inappropriate surgical or medical management.

Many clinical biomarkers in cancer are glycoproteins, but the majority of them only consider the protein levels. Indeed, only alfa-fetoprotein (AFP) in hepatocarcinoma and CA15-3 in breast cancer are clinically monitored for their glycoforms. Aberrant glycosylation occurs frequently in many of the glycoproteins synthesized by tumor cells and often produce changes in protein glycoforms that could be exploited as potential biomarkers for improving diagnosis, prognosis or to study the response to treatment. Ideally, the screening of potential biomarkers should be performed from noninvasive samples like serum or plasma, therefore these glycoproteins with tumor associated-glycoforms should be shed from the tumor cell membrane or secreted into the blood to be detectable. Glycosylation changes that are commonly associated with cancer transformation include fucosylation, sialylation, branching, and polylactosaminylation.Lectins are glycan-binding proteins that bind with great specificity to different glycan moieties. Lectin-based strategies to enrich or fractionate glycoproteins are being extensively used and hold promise in targeted analysis for cancer biomarker discovery. Here we describe the use of lectin chromatography to separate prostate specific antigen (PSA) glycoforms based on their sialic acid linkage from sera of patients with prostate cancer (with PSA levels in the range of 2-20 ng/mL). In particular, agarose-bound Sambucus nigra agglutinin (SNA) lectin which has affinity for terminal α2,6-sialic acids on glycoproteins was used. The protocol included first a previous immunoaffinity step to enrich PSA and to avoid interferences of the most abundant serum glycoproteins. Then, the immunopurified PSA was loaded on the SNA chromatography and two fractions were obtained, the first one (unbound fraction) containing the PSA glycoforms without α2,6-sialic acid (basically α2,3-sialylated PSA glycoforms) and the second one (bound fraction) the α2,6-sialylated PSA glycoforms. The quantification of the PSA eluted in the two fractions allows for the determination of the relative content of both groups of PSA glycoforms. The percentage of the α2,6-sialylated PSA glycoforms is significantly decreased in aggressive prostate cancer compared to indolent prostate cancer and benign prostate hyperplasia, being a promising new glycobiomarker for prostate cancer risk stratification.