<b><br>Introduction:</b> Primary hyperparathyroidism (PHPT) is mainly caused by parathyroid adenoma (PA). Rare variants of PA, weighing >2.0-3.5 g are called \"large\" or \"giant\" adenomas and account for about 1.5% of all PA.</br> <b><br>Aim:</b> The aim of this study was to compare normal-sized and large parathyroid lesions identifying risk factors for severe hypercalcemia.</br> <b><br>Materials and methods:</b> 27 patients with PHPT and parathyroid lesion ≥2.0 cm3 (study group) were compared with 73 patients with PHPT and lesion < 2.0 cm³ (control group). In both groups, the majority were women (81.5% - study group, 90.5% - control group, gender ratios 4.4:9.1, respectively). The patients were examined preoperatively and postoperatively: PTH, creatine, calcium, and phosphate serum and urine concentrations, and calcidiol serum levels were assessed. Preoperative ultrasonography (US) was performed.</br> <b><br>Results:</b> Patients with larger parathyroid lesions had signifficantly higher PTH and calcium serum concentrations and lower serum phosphate and calcidiol concentrations. There were no statistically significant differences in the concentration of creatine in serum and urine, calciuria, or tubular reabsorption of phosphorus (TRP). US relatively underestimated the parathyroid volume by about 0.3-0.4 mL (10% in larger lesions and 43% in smaller ones).</br> <b><br>Conclusions:</b> Due to higher PTH and calcium levels, larger parathyroid adenomas may constitute a higher risk of severe hypercalcemia. In general, US underestimated the parathyroid volume.</br>.

UNASSIGNED: Hypercalcemia-induced posterior reversible encephalopathy syndrome (PRES) is a rare entity primarily associated with iatrogenic vitamin D/calcium overdose, malignancy, or, infrequently, primary hyperparathyroidism.
UNASSIGNED: We present a novel case of an adult male from rural India who experienced recurrent acute pancreatitis caused by hypercalcemia with concurrent manifestation of PRES. Diagnostic evaluation revealed markedly elevated serum calcium levels and parathyroid hormone concentrations, consistent with primary hyperparathyroidism. Imaging studies identified a parathyroid adenoma near the right thyroid lobe, subsequently surgically excised.
UNASSIGNED: This case underscores the importance of considering primary hyperparathyroidism as an underlying cause of PRES, especially in the absence of acute arterial hypertension or autonomic dysfunction. Early recognition and intervention are essential in mitigating the morbidity and mortality of PRES.

Sarcoidosis is a systemic inflammatory condition characterized by noncaseating granulomas. Lung involvement is typical, while extrapulmonary manifestations, notably lymphadenopathy, are observed in a significant proportion of cases. The etiology involves complex interactions among immune cells and mediators, resulting in granuloma formation capable of independently producing 1,25-dihydroxyvitamin D, leading to unregulated hypercalcemia and hypercalciuria. Diagnosis can be challenging, especially when hypercalcemia is the initial symptom. The presence of noncaseating granulomas on biopsy is characteristic of sarcoidosis. We present a case of severe hypercalcemia in a 53-year-old woman, initially suggestive of primary hyperparathyroidism due to non-suppressed intact parathyroid hormone (PTH) levels and unilateral intrathyroidal tracer uptake on a technetium 99m sestamibi parathyroid scan. The patient presented with hypertension, acute kidney injury, and severe hypercalcemia. Initial assessment, including a parathyroid scan, hinted at primary hyperparathyroidism. However, further evaluation, including chest computed tomography (CT) and endobronchial biopsy, revealed sarcoidosis with noncaseating granulomas. Prednisone therapy led to normalization of serum calcium and creatinine levels. The case underscores the complexities in diagnosing sarcoidosis, especially when presenting with severe hypercalcemia. Despite non-suppressed PTH and suggestive imaging, the final diagnosis relied on endobronchial biopsy findings. The study highlights the limitations of conventional diagnostic markers, emphasizing the need for a comprehensive and individualized approach.

In this case, we explore the diagnostic workup of a patient presenting with symptomatic hypercalcemia. Initially suspected to have multiple myeloma, the diagnostic evaluation instead unveiled non-germinal center (non-GC) diffuse large B-cell lymphoma (DLBCL). DLBCL is the most common histologic subtype of non-Hodgkin lymphoma and is heterogeneous in terms of presentation, genetic drivers, and morphology. As primary bone DLBCL is exceedingly rare, the case presented proved to be a diagnostic challenge. The patient presented with one week of weakness, one to two days of nausea, and leg pain. On admission, hypercalcemia, renal failure, anemia, and lytic bone lesions were present and suggestive of multiple myeloma. However, serum protein electrophoresis and immunoglobulin levels did not fit the 2016 World Health Organization (WHO) diagnostic criteria for multiple myeloma. A negative bone marrow biopsy also argued against a diffuse plasma cell neoplasm. Finally, a biopsy from another bone lesion was diagnostic of DLBCL. This case discusses an unusual presentation of DLBCL.

Ewing\'s sarcoma (ES) is a rare malignancy of adolescence that usually presents with clinically apparent disease involving long bones, brought to attention by trauma and/or fractures. Hypercalcemia of malignancy is a well-known phenomenon; however, hypercalcemia is exceptionally rare in ES. This case report discusses a 20-year-old lady who experienced chronic bone pains in her hip and lower limbs, ultimately leading to a hypercalcemic crisis. We emphasize the importance of considering ES as a potential cause of hypercalcemia, highlighting the mechanism, diagnostic and therapeutic challenges, the associated poor prognosis, and the necessity for a multidisciplinary approach to managing the condition.

Hypercalcemia of malignancy (HCM) is an important cancer-related medical emergency. It is a sign of advanced disease with a poor prognosis. We report a case of a 55-year-old man who presented with decreased sensorium, constipation for 4 days, dysphonia, and weight loss for the past three months. The physical examination showed a petrous nodular lesion of the neck in relation to the right sternocleidomastoid muscle. The digital rectal examination showed an enlarged prostate with a nodule of hard consistency. The blood revealed a hypercalcemia of 18.9 mg/dl and a prostate-specific antigen of 319.18 ng/ml. After further investigation, we discovered a squamous cell carcinoma of the larynx with multiple osteolytic bone lesions and a prostate adenocarcinoma. The hypercalcemia was treated with sodium pamidronate with good results. Such severe hypercalcemia demanded further research which revealed that not only the osteolytic lesions contributed to the elevation of calcium serum levels but also the tumor secretion of parathyroid hormone-related protein. This case highlights the importance of not only having a high suspicion for malignancy in patients presenting with hypercalcemia but also being aware of possible additional diagnoses in a patient with an already identified primary pathology.

(1) Background: Parathyroid cystic adenomas (PCA) are rare entities representing only 0.5-1% of parathyroid adenomas, accounting for 1-2% of cases of primary hyperparathyroidism (PHPT). The purpose of this study was to compare classical and functional/secreting cystic parathyroid lesions and identify risk factors for severe hypercalcemia; (2) Methods: A total of 17 patients with PHPT and parathyroid cysts (study group) were compared with the group of 100 patients with hyperparathyroidism caused by adenoma or hyperplasia (control group). In both groups the majority were women (88% vs. 12%, with gender ratio 7, 3:1). The patients were examined preoperatively and postoperatively: PTH, creatine, calcium and phosphate serum and urine concentrations and calcidiol serum levels were assessed; (3) Results: Patients with parathyroid cyst had statistically higher PTH and calcium serum concentration, higher calciuria and lower serum phosphate concentration. There were no statistically significant differences in the concentration of creatine in serum and urine and tubular reabsorption of phosphorus (TRP); (4) Conclusions: Due to higher PTH and calcium levels, cystic parathyroid adenomas could be one of the rare risk factors for severe hypercalcemia and hypercalcemic crisis which can be life threatening.

BACKGROUND: In most cases of parathyroid adenoma (PA), it is not palpable and physical examination shows no remarkable findings. Hence diagnosis requires an index of suspicion. The current paper describes four cases of severe hypercalcemia secondary to PA.
METHODS: Case 1 - 29 years old Sudanese female with history of nausea/vomiting, fatigue, loss of appetite and bone aches. She had large palpable left lower neck swelling, and high calcium and PTH. Ultrasound (US) neck and SPECT/CT scan after sestamibi injection showed left inferior PA. Case 2-73 years old Sudanese male referred with history of abdominal pain and flatulence. He had severely high calcium, elevated parathormone (PTH), and high 24-hour urine calcium. US and SPECT/CT showed a left inferior PA. Case 3-54 years old Bangladeshi male, referred with history of renal colic/urolithiasis. Laboratory results showed severely high calcium and PTH levels. US and SPECT/CT scan showed right inferior PA. Case 4-35 years old Tunisian female, 12 weeks pregnant, referred with recurrent nausea and vomiting of increasing frequency from the second week of pregnancy. Laboratory tests revealed severe hypercalcemia and high PTH. US showed two parathyroid lesions.
CONCLUSIONS: The patients were admitted as emergency cases and investigations diagnosed severe hypercalcemia secondary to PA. All patients underwent neck exploration and PA excision. Histology confirmed PA. The four cases were swiftly assessed and treated before progressing into the more serious hypercalcemic crisis which can lead to grave consequences, particularly in the case of the pregnant female. All patients recovered with no complications and were clinically well with normal calcium level on follow up.
CONCLUSIONS: Severe hypercalcemia must be swiftly and thoroughly assessed to prevent the more serious hypercalcemic crisis. Clinicians need to be suspicious of parathyroid adenoma as a probable cause. Severe hypercalcemia is often accompanied with vomiting, and in pregnant females, this could be mistaken for hyperemesis gravidarum. Excision of the parathyroid adenoma treats the condition and follow up of serum calcium and PTH confirms the favorable outcome of surgery.

Posterior reversible encephalopathy syndrome (PRES) is a rare and severe neurotoxic encephalopathic state characterized by variable neurologic manifestations ranging from headache and confusion to seizures, coma, and reversible subcortical vasogenic edema on imaging. PRES is commonly induced by chronic renal failure, hypertension, chemotherapeutic drugs, and eclampsia. PRES induced by hypercalcemia is uncommon and not widely underlined in the literature. We underline a case of a 61-year-old female diagnosed with advanced breast carcinoma presented with altered sensorium and generalized limb weakness. She was found to have malignant hypercalcemia, and brain imaging demonstrated subcortical vasogenic edema in the occipital and frontal lobe, suggestive of PRES. Her condition gradually improved after the treatment of hypercalcemia.

Hypercalcemia is a common electrolyte abnormality with different causes. Hypercalcemia is most often associated with malignancy and primary hyperparathyroidism and malignancy together account for most cases. Primary hyperparathyroidism manifests as hypercalcemia owing to the overproduction of parathyroid hormone. In most cases, primary hyperparathyroidism manifests due to a solitary parathyroid adenoma. Based on calcium levels, hypercalcemia can be classified as mild, moderate, and severe. Hypercalcemia typically presents with non-specific clinical features. Here, we present the case of a 38-year-old male patient who presented to the emergency department (ED) with acute abdominal pain and a tender abdomen with absent bowel sounds. He had chest radiography and blood tests initially. Chest radiography showed left-sided pneumoperitoneum, and the patient was suspected to have a perforated peptic ulcer due to hypercalcemia secondary to a parathyroid adenoma during the second wave of the coronavirus disease 2019 (COVID-19) pandemic. The findings were confirmed by a computerized tomography scan of the abdomen, and the patient was treated with intravenous fluids for hypercalcemia and was managed conservatively for a sealed perforated peptic ulcer following discussion in the multi-disciplinary team meeting (MDT). The COVID-19 pandemic led to a long waiting list and delays in the timely management of patients requiring elective surgical intervention, such as parathyroidectomy. The patient made a complete recovery and had parathyroidectomy of the inferior right lobe two months later.