대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Metastatic Calcification in Renal failure

Radiologic Findings

Diffuse areas of ground-glass attenuation and calcified consolidations in both lungs with
diffuse bronchovascular bundle thickening and bilateral pleural effusions.
Linear calcifications are also seen in the atrial wall of the heart and vessels of the gastrosplenic region.

Lung, right lower lobe, superior segment, transbronchial lung biopsy:
. No evidence of malignancy in given specimen
. Dystrophic calcified nodule with foreign body reaction

Tc-99m MDP bone scan:
c/w Metastastic calcification in the bilateral lung, kidney, stomach, heart, thyroid, spleen, and soft tissues.

Brief Review

Metastatic calcification of the pulmonary parenchyma may occur in patients with chronic renal failure, pituitary hyperparathyroidism, extensive bone malignancy, hypervitaminosis D, diffuse myelomatosis, and milk-alkali syndrome (1-4).
At autopsy, it was reported to be present in up to 60-80% of patients with chronic renal failure. However, calcification is rarely identified on chest radiograph. Metastatic calcifications commonly consist of parenchymal opacification or poorly defined infiltrates that may simulate pneumonia or pulmonary edema (3-6).

On CT scan, multiple pulmonary nodules and calcification can be seen. In addition to the pulmonary nodules, CT scans can show the presence of calcification in the vessels of the chest wall.

These findings of CT are valuable to differentiate from other causes of pulmonary calcification (tuberculosis, fungal infection, varicella, silicosis, sarcoidosis, metastatic tumor, rheumatic mitral stenosis, alveolar microlithiasis, idiopathic pulmonary ossification (7).

Metastatic pulmonary calcification is a purely interstitial process. The predominant site of calcium deposition is alveolar septa and, to a lesser extent, the pulmonary arterioles, bronchioles, accounting for the lack of interlobular septal thickening.

In the patients with chronic renal failure and primary hyperparathyroidism, excess production of parathyroid hormone makes increased uptake of radionuclide in both lung zones on 99mTc-MDP bone scans.




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Abstract of an AJR article by Hartman et al.
Metastatic calcification was due to chronic renal failure (n = 4), T-cell leukemia (n = 1), multiple endocrine neoplasia type I syndrome (n = 1), and idiopathic hypercalcemia (n = 1).
Numerous nodular opacities measuring 3-10 mm in diameter were seen on the chest radiographs in five cases, and patchy areas of parenchymal opacification were seen in two cases. Calcification of the nodules was evident in two cases. On CT scans, pulmonary nodules were present in all seven cases. These nodules were predominant in the upper lung zone in three cases, were diffuse in three cases, and were predominant in the lower lung zone in one case. Calcification of the nodules was evident on the CT scans in four of the seven cases, and calcification of vessels in the chest wall was evident in six of seven cases. Other findings on CT scans included diffuse areas of ground-glass attenuation (n = 3) and patchy consolidation (n = 2).
Numerous small nodules are the most common finding on the chest radiographs of patients with metastatic pulmonary calcification. The calcific nature of the nodules is seldom obvious, however. Pulmonary nodules are also the most common finding on CT scans, where the calcific nature of the nodules is more readily apparent. Additionally, calcification is often seen in the vessels of the chest wall on CT scans. The combination of calcified nodules and calcified vessels in the chest wall on CT scans may be characteristic.

References

1. Karltreider HB, Baum GL, Bogarty G, McCoy MD, Tucker M. So-called "metastatic" calcification of the lung. Am J Med 1969; 46:188-196
2. Conger JD, Hammond WS, Alfrey AC, Contiguglia SR, Stanford RE, Huffer WE. Pulmonary calcification in chronic dialysis patients: clinical and pathologic studies. Ann Intern Med 1975; 83:330-336
3. Mootz JR, Sagel SS, Roberts TH. Roentgenographic manifestations of pulmonary calcifications. Radiology 1973; 107:55-60
4. Felson B. Widespread parenchymal calcifications. In: Felson B. Chest roentgenology. Philadelphia: Sanders, 1973;474-475
5. McLachlan MSF, Wallace N, Senevirante C. Pulmonary calcification in renal failure: report of three cases. Br J Radiol 1986; 41:99-106
6. Margolin RJ, Addison JE. Hypercalcemia and rapidly progressive respiratory failure. Chest 1984; 86:767-769
7. Hartman TE, Muller NL, Primack SL, et al. Metastatic pulmonary calcification in patients with hypercalcemia: findings on chest radiographs and CT scans. AJR 1994;162:799-802

Keywords

Lung, Metabolic and storage lung disesae,