Metastatic pulmonary calcification: Experience from a single center in Singapore

Abstract

Metastatic pulmonary calcification (MPC) was seen in 79% of patients with end-stage renal disease (ESRD) during autopsy. However, it is not commonly diagnosed in vivo. Its pathogenesis is not fully understood. We report a retrospective series of 5 cases of MPC from a single center in Singapore. MPC were diagnosed using radiological or histological features. Mean onset of MPC from diagnosis of ESRD was 22.6 ± 3.1 years. One patient remains asymptomatic. Four patients died, one was related to MPC. All patients had calcifications at the lung apices on radiological studies. Three patients with MPC were diagnosed based on radiological features while 2 had histological features. Four patients underwent parathyroidectomy without radiological changes before parathyroidectomy. Median intact parathyroid hormone of this series was 5.6 pmol/L (IQR 1.3-139.4), alkaline phosphatase 74 U/L (IQR 62-461), calcium 2.10 mmol/L (IQR 1.85-2.40), and phosphate 1.30 mmol/L (IQR 0.87-1.63). The observed low iPTH suggests that MPC might occur in low iPTH. Our case series showed MPC might occur in low iPTH after parathyroidectomy, in contrast to existing literature that suggests MPC is diagnosed in patients with elevated iPTH. Parathyroidectomy does not prevent MPC.

Metastatic pulmonary calcification on bone scintigraphy of a patient with lupus nephritis and end-stage renal disease

“…MPC occurs most commonly in patients with ESRD, particularly those on hemodialysis [8] and those with secondary hyperparathyroidism or hypercalcemia [9] . Although not a common clinical manifestation, previous reports have estimated that up to 79% of patients with ESRD may have evidence of MPC upon autopsy [10] . Clinical symptoms of MPC depend on the severity of underlying disease but most patients are asymptomatic as lung function is generally not affected.…”

A 71-Year-Old Man With Dyspnea and Cough During Chemotherapy

“…In the current patient, the rapid decline in serum calcium levels during calcitonin infusion and progressive renal failure due to infection and dehydration prior to admission to our hospital were most likely the causes of rapid MPC development, in addition to the hyperphosphatemia caused by hypoparathyroidism following parathyroidectomy. 6 The pathologic findings suggest that acute lung injury developed due to OP surrounded by the disseminated calcifications. Cough, dyspnea, and hemoptysis are nonspecific common clinical symptoms of MPC, but in the current case, echocardiography and bronchoscopy excluded most of the differential diagnoses that were considered (eg, heart failure, pulmonary edema, drug-induced pneumonia, atypical pneumonia).…”

A Case of Metastatic Pulmonary Calcification Detected on 99mTc-MDP Bone Scan and 99mTc-FAPI Scan

“…It is often associated with conditions that lead to hypercalcemia and can have either benign or malignant causes. [4][5][6][7] MRI findings are helpful for identifying calcium accumulation due to a metabolic disorder, although nuclear imaging with 99m Tc-MDP is a more specific and cost-effective method for diagnosis. 4,8,9 Radionuclide imaging is likely the most sensitive technique for early detection of metastatic pulmonary calcification.…”

“…Metastatic pulmonary calcification is a metabolic lung condition characterized by the accumulation of calcium in the pulmonary tissue. It is often associated with conditions that lead to hypercalcemia and can have either benign or malignant causes 4–7 . MRI findings are helpful for identifying calcium accumulation due to a metabolic disorder, although nuclear imaging with 99m Tc-MDP is a more specific and cost-effective method for diagnosis 4,8,9 .…”