Metastatic Pulmonary Calcification in Multiple Myeloma in a 45-Year-Old Man

Metastatic calcification has been associated with multiple-myeloma-induced hypercalcemia. Despite of a relatively high prevalence of metastatic pulmonary calcification in patients with multiple myeloma, only a few cases have been clinically and radiologically detected. A 45-year-old Hispanic male presented to the Emergency Department with complaint of worsening weakness and myalgia. Laboratory findings revealed renal insufficiency and hypercalcemia. CT scan of chest revealed calcified pleural and pulmonary nodule. Technetium (Tc) 99 bone scan revealed diffuse activity in the pulmonary parenchyma consistent with metastatic pulmonary calcification. Metastatic pulmonary calcification, despite its high prevalence, remains undetected. This is, in part, due to its radiographic characteristic properties that evade detection by routine imaging studies. We present a case of a metastatic pulmonary calcification in a patient diagnosed with multiple myeloma and chronic kidney disease, as well as a brief literature review including clinical findings and treatment options. 1. Introduction Metastatic pulmonary calcification (MPC) is a common complication of multiple myeloma (MM) and it is result of the high levels of calcium-phosphate products deposited in alveolar and vessel walls of normal lung [1]. It is known to be aggravated by physical stress or tissue injury, which clinically manifests as progressive dyspnea, hypoxemia, and worsening symptoms of respiratory insufficiency and findings of restrictive pulmonary function test [2]. Both benign and malignant oncological etiologies can cause MPC. Some of the “benign” causes include excess exogenous administration of calcium and vitamin D, hyperparathyroidism, hypervitaminosis D, chronic renal insufficiency, osteoporosis, and osteitis deformans. Malignant etiologies include multiple myeloma, parathyroid carcinoma, leukemia, lymphoma, breast carcinoma, synovial carcinoma, choriocarcinoma, and hypopharyngeal squamous carcinoma. In metastatic calcification, common sites of calcium deposits involve lung, kidney, gastric mucosa, heart, and blood vessels. Histopathologically, MPC involves diffuse calcium deposition in the lung with deposits typically in alveolar septa, bronchi, pulmonary vessels, and myocardium [1]. The composition of the deposits varies, with lung and soft tissue tumors primarily having a hydroxyapatite calcification while the renal failure calcifications present [3]. Based on the calcium deposition in the lungs three patterns have been identified: multiple diffuse calcified nodules (as seen in our