Parathyroid hormone related protein (PTHrP) mediated hypercalcaemia complicating enteropancreatic malignancy in multiple endocrine neoplasia type 1 (MEN 1)

Severe hypercalcemia due to metastatic pancreatic neuroendocrine tumor: a case report

BACKGROUND

Hypercalcemia of malignancy, as a paraneoplastic syndrome, is the most common metabolic disorder that accounts for 30% of malignancies and usually has a poor prognosis. Neuroendocrine tumors are uncommon and arise from neuroendocrine cells throughout the body. Actually, paraneoplastic hypercalcemia in neuroendocrine tumors is unusual and mostly associated with parathyroid hormone-related protein (PTHrP) secretion.

CASE PRESENTATION

We report a 51-year-old Iranian man who presented with nausea, vomiting, and significant weight loss for 1 month. Laboratory data revealed calcium of 26 mg/dl, accompanied by low level of PTH. Octreotide scan revealed a large donut-shaped octreotide avid lesion in the epigastric region at the right side of the mid-abdomen, with multiple varying size foci of abnormally increased radiotracer uptake in the epigastric region and both lobes of the liver. Endoscopic ultrasonography demonstrated a large heterogeneous mass lesion with irregular outline and good demarcation in the body of the pancreas with diffuse foci of calcification. Percutaneous biopsy of the liver mass demonstrated a well-differentiated neuroendocrine tumor (low grade) confirmed by immunohistochemistry with strongly positive chromogranin and synaptophysin stain. Hypercalcemia was treated with hydration, few sessions of hemodialysis, calcitonin, and denosumab injection. However, the patient developed symptomatic hypocalcemia. Oncology consultation led to prescription of long-acting octreotide 30 mg monthly and everolimus daily.

CONCLUSION

Pancreatic neuroendocrine tumor could lead to malignant hypercalcemia; secretion of PTHrP is the most common cause, and signs and symptoms are usually milder than paraneoplastic syndrome due to hematologic and solid tumor. Generally, survival is better; however, its treatment is challenging, and primary debulking surgery is often required. A team approach to management is important at all points.

Rare case of pancreatic neuroendocrine tumour presenting as paraneoplastic hypercalcaemia

An asymptomatic 68-year-old woman who presented with an isolated hypercalcaemia was diagnosed with a rare, previously unsuspected parathyroid hormone-related peptide (PTHrP)-producing pancreatic neuroendocrine tumour. She underwent an extensive operation including vascular resection and reconstruction, resulting in successful removal of the tumour with negative margins. Medical and surgical management of pancreatic neuroendocrine tumours and PTHrP-mediated paraneoplastic hypercalcaemia is discussed.

Concurrent primary hyperparathyroidism and humoral hypercalcemia of malignancy in a patient with multiple endocrine neoplasia type 1

We report a patient with multiple endocrine neoplasia type 1 presenting with elevation of parathyroid hormone-related protein (PTHrP) from a metastatic pancreatic neuroendocrine tumor (PNET), and parathyroid hormone (PTH) from primary hyperparathyroidism, resulting in severe hypercalcemia. Parathyroid hormone-related protein production by the PNET was confirmed by immunohistochemical analysis. Hypercalcemia and elevated PTHrP improved markedly with hepatic artery chemoembolization of liver metastasis. Thus, in multiple endocrine neoplasia type 1, correct identification of the cause of hypercalcemia as PTHrP production from a PNET or PTH production from a parathyroid tumor has important therapeutic implications.

A case of a giant glucagonoma with parathyroid hormone-related peptide secretion showing an inconsistent postsurgical endocrine status

A 53-year-old woman was admitted because of a giant pancreatic tumor. Hypercalcemia and a high serum parathyroid hormone-related peptide (PTHrP) level were observed. A hypoglycemic attack occurred during pancreatectomy, and the surgical specimen revealed a PTHrP-secreting glucagonoma. Liver metastases developed 1 and 5.5 years later, and bone metastases appeared 6 years after surgery. Her serum PTHrP concentrations remained normal after surgery, despite re-elevation of the serum glucagon concentration after recurrence. The clinical course of this case illustrates the process of development of neuroendocrine tumors secreting two or more hormones.