Tumour lysis syndrome (TLS) is a potentially fatal oncological emergency characterised by rapid cellular breakdown resulting in hyperkalaemia, hyperphosphataemia, hyperuricaemia, and hypocalcaemia, with subsequent acute kidney injury, cardiac dysrhythmias, and multi-organ dysfunction. It most commonly occurs following initiation of anti-cancer therapy in highly proliferative haematological malignancies. Spontaneous tumour lysis syndrome (STLS), occurring in the absence of a therapeutic trigger, is considerably rarer, particularly in solid tumours. We report a 55-year-old female presenting with progressive abdominal distension, pain, constipation, and oliguria progressing to anuria. Investigation demonstrated a 14 × 12 cm pelvic mass with extensive peritoneal and omental metastatic disease and large-volume ascites. During admission, prior to any anti-cancer therapy, she developed severe refractory hyperkalaemia, peaking at 8.1 mmol/L, alongside hyperphosphataemia >1.45 mmol/L (peaking at 2.44 mmol/L), hyperuricaemia of ≥476 µmol/L (peaking at 784 mmol/L), ionised hypocalcaemia ≤1.12 mmol/L (1.06 mmol/L), and rapidly progressive acute kidney injury, with creatinine rising from a baseline of 54 µmol/L to 310 µmol/L. These abnormalities fulfilled the Cairo-Bishop criteria for both laboratory TLS by achieving two or more deranged serum biochemical markers or changes >25% from baseline, as well as clinical TLS with the presentation of acute kidney injury and eventual death. Histopathological and genetic assessment ultimately identified a dedifferentiated endometrial carcinoma. Despite appropriate intravenous hydration, rasburicase, and repeated correction of electrolyte abnormalities, renal function and multi-organ dysfunction progressively deteriorated. The patient died nine days after admission, before anti-cancer therapy could be commenced. It was this absence of anti-cancer therapy and the trigger for the TLS that led us to classify this patient's presentation as STLS. STLS is exceptionally uncommon in solid malignancies but may occur in aggressive tumours with a high disease burden and rapid cellular turnover. This case is particularly notable because biochemical evidence of TLS preceded biopsy and any oncological treatment, supporting a genuinely spontaneous presentation. Furthermore, conventional risk stratification classified this patient as low risk, demonstrating the limitations of existing approaches when applied to rare, aggressive solid malignancies. STLS should be considered in patients with newly diagnosed or suspected solid malignancy who develop otherwise unexplained hyperkalaemia, hyperphosphataemia, hyperuricaemia, hypocalcaemia, or acute kidney injury, even before anti-cancer treatment. Early recognition and application of TLS diagnostic criteria are essential to facilitate prompt hydration, urate-lowering therapy, and correction of life-threatening metabolic abnormalities; however, it is key to note that, despite this, this condition remains to possess a poor prognosis. Greater awareness of STLS in aggressive solid tumours may enable earlier intervention and potentially improve outcomes for this fulminant condition.

Pseudohypoparathyroidism (PHP) is a rare disorder characterized by classic hypocalcemia despite normal or elevated parathyroid hormone (PTH). Pseudohypoparathyroidism is marked by tissue resistance to circulating PTH and is associated with the typical Albright hereditary osteodystrophy (AHO) phenotype, including developmental delay, obesity, short stature, round face, brachydactyly, and ectopic ossifications. Pseudohypoparathyroidism is classified into multiple types based on the extent of clinical features and hormonal resistance beyond the parathyroid glands. We present a 15-year-old boy with recurrent seizures, developmental delay, deafness, poor dentition, and skeletal dysplasia. He did not have the typical AHO phenotype, and investigations revealed severe hypocalcemia, hyperphosphatemia, and elevated PTH, supporting a diagnosis of PHP. Imaging showed bilateral basal ganglia calcification, brachydactyly, clinodactyly, ischiopubic hypoplasia, and skeletal changes beyond those typically observed in patients with typical PHP. Whole-exome sequencing revealed a homozygous missense variant in exon 9 of the PTH1 receptor (PTH1R) gene, suggestive of Eiken syndrome (ES). This variant has not been described in the handful of published cases of ES, and we highlight the rare PTH1R pathogenic variant that leads to PHP and skeletal dysplasia.

Pseudohypoparathyroidism (PHP) type 1A is a rare inherited disorder characterized by resistance to parathyroid hormone and, typically, features of Albright hereditary osteodystrophy. We report a late-onset case in a 59-year-old woman who presented with cognitive decline, behavioral and psychiatric symptoms, gait instability, and seizure-like episodes. Laboratory tests showed hypocalcemia, hyperphosphatemia, and elevated parathyroid hormone levels. Brain imaging revealed symmetrical calcifications in the bilateral basal ganglia, thalami, and periventricular regions, while electroencephalography showed epileptiform discharges. Genetic testing identified a heterozygous missense variant in GNAS, c.285C>G: p.Ser95Arg, which has not been previously reported. Based on the clinical manifestations, biochemical abnormalities, neuroimaging findings, and genetic results, the patient was diagnosed with late-onset atypical PHP type 1A. After treatment with calcium supplementation, calcitriol, and levetiracetam, no further seizures occurred, and serum calcium returned to the normal range, although cognitive improvement was limited. This case suggests that calcium-phosphate metabolism and parathyroid hormone levels should be assessed in adults presenting with symmetrical intracranial calcifications, seizures, or cognitive impairment. Genetic testing may further support early diagnosis and help reduce misdiagnosis.

Autosomal dominant hypophosphatemic rickets (ADHR) is a rare genetic disorder, characterized by fibroblast growth factor 23 (FGF23)-mediated renal phosphate wasting and impaired bone mineralization. Iron deficiency in ADHR increases FGF23 production and can worsen hypophosphatemia. Evidence to guide optimal management in severe adult cases remains limited. We report the use of burosumab as bridging therapy in a 19-yr-old woman with genetically confirmed ADHR (FGF23 p.Arg176Trp), severe osteomalacia, iron-deficiency anemia, and a low-energy femoral diaphyseal fracture complicated by nonunion despite conventional therapy. Treatment with burosumab resulted in rapid clinical improvement, with marked reduction in musculoskeletal pain and stiffness, and restoration of independent ambulation within four months. BMD increased substantially (+11.7% at the LS and +14.2% at the total hip at 5 mo; +63.8% and +55.5% from baseline at approximately 11 mo, respectively), while trabecular bone score remained within the normal range, a pattern consistent with improved mineralization and preserved trabecular texture. Serum phosphate increased but did not consistently normalize at trough, prompting dose escalation. At 8 mo, the burosumab dose was increased to 50 mg (1.25 mg/kg) due to persistent hypophosphatemia; with concurrent oral iron replacement, transient hyperphosphatemia (1.61 mmol/L) occurred and was managed by delaying the next dose by 14 d and reducing the dose back to 1 mg/kg. The patient also underwent additional surgical intervention, which may have contributed to the overall outcome; radiographic callus formation was evident 5 mo post-surgery. To our knowledge, this is the first full-length report describing burosumab use in genetically confirmed ADHR with longitudinal biochemical and densitometric follow-up, and it highlights the importance of careful monitoring of phosphate and iron indices when combining therapies.

Leptospirosis is a zoonotic disease that can cause severe acute kidney injury (AKI) in dogs. A three-year-old intact male Border Collie, unvaccinated against leptospirosis, with a history of exposure to urban stagnant water presented with acute vomiting, diarrhea, and moderate dehydration. Initial evaluation revealed extreme azotemia (blood urea nitrogen, 175.8 mg/dL; creatinine, 11.10 mg/dL) and hyperphosphatemia (13.6 mg/dL), consistent with International Renal Interest Society (IRIS) AKI Grade V; urine output remained within the non-oliguric range (2.15-3.0 mL/kg/h) throughout the catheterized period (Day 0-4). Clinical and imaging findings supported acute intrinsic renal injury over chronic kidney disease. A multiplex real-time PCR targeting the Leptospira LipL32 gene was positive in urine (Ct 31.10), providing molecular evidence supporting active infection or shedding of pathogenic Leptospira spp., without identifying the infecting serovar. Empirical antimicrobial therapy targeting suspected leptospirosis, together with intravenous fluid therapy, was initiated on clinical suspicion prior to the PCR result. Renal and inflammatory biomarkers improved progressively over 22 days without extracorporeal kidney support; the patient's non-oliguric status, hemodynamic stability, and objective clinical improvement supported this management approach. This report documents, in detail, the clinicopathological recovery trajectory of a dog with non-oliguric IRIS Grade V AKI associated with suspected leptospirosis, information that may assist clinicians in recognizing and managing similarly severe presentations without assuming that dialysis is always required.

Background: Infantile dilated cardiomyopathy (DCM) is uncommon but carries substantial mortality, particularly when accompanied by neurological, ocular, or metabolic abnormalities. Long-Olsen-Distelmaier syndrome is a rare mTORopathy caused by heterozygous gain-of-function variants in RRAGC and may include cortical malformations, congenital cataracts, mineral disturbances, and early-onset DCM. Case Summary: We describe a term male infant born to consanguineous parents with hypocalcemia and hyperphosphatemia, bilateral frontoparietal polymicrogyria, bilateral congenital lamellar cataracts, small patent ductus arteriosus and ventricular septal defect, and initially preserved biventricular function. At 53 days of age, he developed cardiogenic shock, severe lactic acidosis, and hyperkalemia during a rhinovirus/enterovirus-positive respiratory illness. Echocardiography showed severe DCM with marked left ventricular dilatation and an ejection fraction of 27%. Despite multi-agent inotropic support, ventricular function did not recover, and he died at approximately two months. Accordingly, the contemporaneous clinical WES record documented a heterozygous RRAGC c.343T>C, p.(Trp115Arg) variant, reported by the diagnostic laboratory as likely pathogenic. The variant was subsequently standardized in this manuscript as NM_022157.4:c.343T>C, and an independent manuscript-level ACMG/AMP reassessment was concordant. Conclusions: Because p.(Trp115Arg) was previously reported, the principal contribution is detailed documentation of rapid progression from preserved neonatal ventricular function to fatal infantile DCM, while extending the clinical and geographic spectrum of RRAGC-related Long-Olsen-Distelmaier syndrome. Respiratory viral detection should be interpreted cautiously because myocarditis was not established; early exome-based testing should be considered in infants with cardiomyopathy and multisystem abnormalities.

Hypoparathyroidism is the most common complication after total thyroidectomy and may be particularly severe in pediatric Graves' disease. We report the case of a 14-year-old boy with Graves' disease who developed profound postoperative hypocalcemia after total thyroidectomy, with serum calcium 5.9 mg/dL, ionized calcium 0.83 mmol/L, and undetectable parathyroid hormone. Despite intravenous and high-dose oral calcium plus calcitriol, biochemical control remained poor, with persistent hypocalcemia, hyperphosphatemia, and ongoing treatment requirements after 16 days. Off-label subcutaneous palopegteriparatide, a long-acting PTH(1-34) prodrug, was started after multidisciplinary assessment and informed family consent. Serum calcium improved within 48 h, intravenous calcium was stopped after 5 days, and calcitriol, sevelamer, and calcium acetate were discontinued within 11 days. Treatment was well tolerated. This case suggests that early PTH replacement may be a useful rescue strategy in selected children with severe refractory post-thyroidectomy hypocalcemia.

Milky white serum in infancy is rare and usually reflects a metabolic disorder; renal causes are distinctly uncommon. We report a 7-month-old male infant who presented with generalized edema and strikingly lipemic serum. Examination revealed lipemia retinalis, while investigations showed extreme hypertriglyceridemia and nephrotic range proteinuria. Initial tests also suggested hyperproteinemia and hyperphosphatemia, but repeat measurements confirmed hypoalbuminemia. Whole exome sequencing identified compound heterozygous variants in the NPHP1 gene, comprising one pathogenic variant and one variant of uncertain significance. Although parental testing was not performed, the combined clinical and genetic findings supported a diagnosis of congenital nephrotic syndrome. Parental testing, though not performed, combined clinical and genetic findings supported a diagnosis of congenital nephrotic syndrome. This case highlights that, although rare, congenital nephrotic syndrome can present with severe dyslipidemia and milky serum in infancy, and underscores the need to recognize potential laboratory estimation errors in lipemic samples.

Hypercalcaemia is a recognised complication of thyrotoxicosis usually related to increased bone resorption. However, coexistent hyperphosphataemia is uncommon and may create diagnostic uncertainty. It is postulated that serum calcium and phosphate levels rise due to high bone turnover and increased renal reabsorption of phosphate in response to excess thyroxine. Hypercalcaemia may also alter the clinical presentation of thyrotoxicosis, making both diagnosis and management challenging. We report two patients with this unusual biochemical presentation. The first patient was a 69-year-old woman who presented with body aches, lethargy, low mood, constipation, polyuria, and proximal muscle weakness for 2 months. The second was a 56-year-old woman who presented with palpitations, anxiety, tremulousness, dyspnoea, dysphagia, and headache for 4 months. Both had multinodular goitres (MNGs) without eye disease. Their TSH levels were undetectably low with extremely high free T4 levels. Serum calcium and phosphate levels were high in both patients. ALP levels were mildly elevated, vitamin D levels were deficient or insufficient, and parathyroid hormone (PTH) levels were low-normal. DXA scans revealed severe osteoporosis. Both patients improved clinically and biochemically with adequate intravenous hydration, frusemide, carbimazole, propranolol, and bisphosphonates. The second patient underwent a successful left thyroid lobectomy, while the first patient remained well on medical treatment. Unexplained hypercalcaemia and hyperphosphataemia should alert the clinicians to the possibility of underlying thyrotoxicosis. Prompt recognition and management is essential to prevent bone loss, correct metabolic abnormalities, and avoid complications. Clinicians should also consider the possibility of hypercalcaemia associated with thyroid dysfunction in patients presenting with nonspecific symptoms such as fatigue, constipation, proximal weakness, polyuria, or mood changes.

Disorders of phosphorus are common in critically ill horses, often occurring secondary to conditions such as endotoxemia, renal failure, or malnutrition. Phosphate imbalances can impair skeletal and cardiac muscle function, erythrocyte integrity, and bone metabolism, thereby complicating recovery. Diagnosis relies on routine biochemical testing. Treatment depends on severity: mild hypophosphatemia may be managed with oral supplementation, whereas severe cases require slow intravenous replacement with calcium monitoring. Hyperphosphatemia is addressed by promoting excretion and limiting absorption. Correction of the underlying disease and concurrent electrolyte abnormalities is essential. Although well documented in other species, equine-specific data remain limited.

Patients receiving kidney replacement therapy (KRT) experience high medication burden and are at increased risk for medication-related problems and non-adherence. The objective of this study was to evaluate pharmacist-led interventions on adherence and phosphorus control. It was a prospective, three-phase study integrating a pharmacist into a hospital-based dialysis program that provided hemodialysis (chronic, acute, and in-patient), peritoneal dialysis, and home hemodialysis. This study showed improved adherence, phosphorus control, and reduced discrepancies among the studied population. Pharmacist integration into the program also improved outcomes and workflow efficiency. Upon completion of this educational activity, the learner will demonstrate increased knowledge of the impact of pharmacist-led interventions on medication adherence and clinical outcomes in patients on KRT.