BACKGROUND: Doege-Potter syndrome is a rare paraneoplastic phenomenon associated with solitary fibrous tumors of the pleura (SFTPs). It is characterized by the presence of severe, sustained, and treatment-refractory hypoglycemia. Hypoglycaemia, which may be the sole symptom at disease onset, is mediated by the secretion of high-molecular-weight insulin-like growth factor (IGF-2). Most tumors exhibit benign behavior, with a 100% survival rate at 5 years. However, 10% of these tumors may display aggressive behavior with local or metastatic recurrence. We present a clinical case of a patient with a benign solitary fibrous tumor of the pleura who presented with symptomatic hypoglycemia and required pulmonary and pleural surgical resection to control the paraneoplastic phenomenon.
METHODS: A Hispanic 46-year-old man presented with a 15-day history of transient alterations in consciousness worsened by fasting. The relevant medical history included obstructive sleep apnea treated with continuous positive air pressure (CPAP) and previous smoking. In-hospital studies revealed noninsulinemic hypoglycemia and a benign SFTP. Complete surgical resection was performed while the patient received dextrose fluids and corticosteroids perioperatively for hypoglycemia. Subsequently, the hypoglycemia resolved, and the patient was followed-up without disease recurrence.
CONCLUSIONS: Doege-Potter syndrome is challenging to recognize. However, effective treatment can be achieved with a high survival rate. Raising awareness among healthcare professionals about the recognition of this paraneoplasic syndrome patients will improve diagnostic suspicion, biochemical confirmation, the development of diagnostic and therapeutic guidelines, and the creation of predictive indices for aggressive presentations requiring closer monitoring.

A female in her 50s developed a headache, collapsed and was noted to have an acute atraumatic subdural haemorrhage (SDH) requiring surgical evacuation and intracranial pressure-directed therapy. Her background included recurrent epistaxis, severe generalised bone pain and multiple insufficiency fractures and an undifferentiated autoimmune connective tissue disease. Chronic hypophosphataemia, elevated alkaline phosphatase and raised fibroblast growth factor 23 (FGF23) were also noted. An MRI head and subsequent 68Ga CT/positron emission tomography scan demonstrated an intensely avid tumour in the right ethmoid sinus, extending intracranially. Phosphate was aggressively replaced, and alfacalcidol was initiated to circumvent the effects of FGF23 on her kidneys and bone minerals. The tumour was biopsied and then definitively resected via combined endonasal and craniotomy approaches, resulting in good clinical improvement. FGF23 titre and serum phosphate both normalised leaving the diagnosis of a phosphaturic mesenchymal tumour-secreting FGF23, leading to tumour-induced osteomalacia.

Posttransplant malignancies are an important complication of solid organ transplantation. Kidney transplant recipients are at particularly high risk of cancer development. The most relevant risk factors of carcinogenesis are the use of immunosuppressive agents and oncogenic viral infections. Additionally, immune dysregulation caused by these factors may predispose to various types of organ damage. Paraneoplastic glomerular diseases are one of the most interesting and understudied cancer manifestations. The appropriate diagnosis of paraneoplastic glomerular damage can be challenging in kidney transplant recipients, due to factors inherent to concomitant medication and common comorbidities. Recent advances in the field of molecular and clinical nephrology led to a significant improvement in our understanding of glomerular diseases and their more targeted treatment. On the other hand, introduction of novel anticancer drugs tremendously increased patients\' survival, at the cost of kidney-related side effects. Our review aims to provide insights into diagnosis and treatment of paraneoplastic glomerular diseases, with a special attention to kidney transplant recipients.

Stiff-person syndrome (SPS) is a rare neurological disorder characterized by chronic and progressive axial muscle rigidity and paroxysmal painful muscle spasms. The present case study described an SPS patient (increased anti-GAD65 antibody in serum and cerebrospinal fluid) with co-occurring Hashimoto\'s thyroiditis and decreased C3 complement levels. The clinical presentation, diagnostic approach, and treatment employed for this unique case were comprehensively described in detail. In this case, we comprehensively presented a case of SPS with co-occurring Hashimoto\'s thyroiditis and an associated decrease in serum C3 complement, as well as a discussion on the current data on this topic.

UNASSIGNED: Relapsing polychondritis (RP) is an uncommon autoimmune disease that causes inflammation of the cartilage and proteoglycan-rich structures, including the ear, nose, and airway. Paraneoplastic RP is a subset of RP that occurs in some individuals following the detection and treatment of certain types of cancers. FDG PET/CT helps with early diagnosis of RP, identifying inflammatory areas even in the absence of symptoms, and guiding the selection of appropriate biopsy sites. Here, we present a case of adenocarcinoma of the lung presenting with paraneoplastic symptoms of RP as initial presentation, and symptoms were resolved after 3 cycles of chemotherapy.

Paraneoplastic glomerular disease (PGD) develops from tumor cell products, leading to renal dysfunction. Unlike direct tumor effects, PGD illustrates the complex association between cancer and diverse clinical presentations and outcomes. Initially detected in a Hodgkin\'s disease patient, current research has defined diagnostic criteria based on PGD symptoms and cancer progression. PGDs, although rare (found in <1% of adult cancer patients with overt renal manifestations), are crucial, as they can signal cancer onset and frequently resist standard glomerulonephritis treatments. The emerging field of onconephrology studies this relationship between kidney disorders and cancers. The exact cause of many PGD cases remains unknown. This review examines PGDs, their clinicopathological features, related cancers, and mechanisms, emphasizing the need for early diagnosis and tailored treatment for kidney disease and linked cancer.

Small cell carcinoma of the bladder is an extremely rare and aggressive disease with poor overall survival, as it is often diagnosed in later stages. Similarly, paraneoplastic thrombocytopenia is also a rare phenomenon infrequently described in the literature. Given its rarity but responsiveness to chemotherapy, awareness of atypical presentations helps facilitate appropriate treatment. A 76-year-old gentleman was admitted to an Australian regional hospital from a small remote hospital with complaints of five months of anorexia, lethargy, weight loss, and new-onset pleuritic chest pain with a past medical history of prostatomegaly and a distant history of localised seminoma treated with surgical resection and radiotherapy alone. Physical examination revealed new rapid atrial fibrillation and mild hypoxia alongside right upper quadrant tenderness and fullness. The patient underwent pleural drainage, cytology, and computed tomography, was subsequently diagnosed with small cell carcinoma of the bladder, and rapidly developed isolated thrombocytopenia that improved with inpatient chemotherapy with carboplatin/etoposide. He was eventually discharged home after a lengthy admission. On follow-up, he had cycle 2 of treatment as an outpatient before undergoing palliative treatment at the patient\'s small remote hospital. This highlights the importance of both prompt recognition and treatment of rapidly growing small cell carcinomas when they first present atypically with uncharacteristic paraneoplastic syndromes to reduce morbidity and mortality.

Anterior mediastinal masses, including thymomas, can present with thoracic symptoms or paraneoplastic syndromes, especially in adults over 40. Diagnosis involves imaging and biopsy, and treatment includes surgical resection and chemotherapy, depending on the stage. A 31-year-old male, with a history of alcohol use disorder and a former smoker, presented with increasing heartburn, shortness of breath, left shoulder pain, and chest pain. Imaging revealed an anterior mediastinal mass with pleural thickening and a small effusion. A biopsy confirmed a B2-type thymoma. Initial treatment included cyclophosphamide, doxorubicin, and cisplatin, resulting in significant tumor reduction and pleural effusion resolution. The patient underwent planned surgical resection following neoadjuvant chemotherapy. This case highlights the complexity of advanced thymoma treatment and the effectiveness of neoadjuvant chemotherapy in reducing tumor burden, the associated effusions, and improving outcomes. Continuous follow-up and further studies are essential to optimize treatment protocols for advanced thymoma.

Various conditions under the umbrella term of vasculitis have been well documented in the literature. These have been classified into small, medium, and large vessel vasculitis. In addition, vasculitis has been categorized into radiation-induced, systemic, and paraneoplastic. Of these, paraneoplastic vasculitis accounts for 2-5% of all cases of vasculitides and is less well documented. We present a case of a female patient with a history of breast cancer presenting with an upper gastrointestinal tract (GI) bleed, which subsequently revealed an underlying diagnosis of systemic vasculitis, possibly paraneoplastic. This case highlights the importance of imaging for revealing underlying vasculitis as an etiology of GI bleed.

BACKGROUND: There are few studies that have analyzed the characteristics of hypercalcemia in hospitalized oncological patients. Our objectives were to describe the clinical characteristics of hospitalized patients with paraneoplastic hypercalcemia and to identify prognostic variables for mortality.
METHODS: This was an observational, longitudinal, retrospective, and bicentric study. It included adult patients admitted to two hospitals in Málaga, Spain (2014-2018). The minimum follow-up period was 2 years or until death.
RESULTS: A total of 154 patients were included; the majority (71.4%) were admitted to the internal medicine department. The median follow-up was 3.5 weeks (interquartile range [IQR] 1.1-11.5). The mean (standard deviation) age was 67.6 (12.3) years, with a predominance of males (58.4%). The median (IQR) serum calcium at admission was 13.2 (11.8-14.6) mg/dl. The most common neoplasms were pulmonary (27.3%), hematologic (23.4%), urological (13%), and breast (12.3%). Furthermore, 56.5% of cases had a known history of neoplasia at the time of diagnosis. The parathyroid hormone (PTH) level was determined in 24%; of these, 10.8% had elevated levels. In all, 95.5% of patients died during follow-up. The median survival was 3.4 weeks (95% confidence interval 2.6-4.3). Factors associated with higher mortality were age, serum calcium at admission, previous history of neoplasia, etiology other than multiple myeloma, and noncorrection of hypercalcemia.
CONCLUSIONS: In hospitalized patients, paraneoplastic hypercalcemia was associated with high short-term mortality. Several factors associated with a worse prognosis were identified in these patients.