Pulmonary calcification in renal failure. Report of three cases

Aggressive pulmonary calcification developed after living donor kidney transplantation in a patient with primary hyperparathyroidism

Metastatic pulmonary calcification, defined as calcium deposition in the intact lung, is commonly seen in patients with chronic renal failure, and it is known to be a benign clinical condition when detected by chance in an asymptomatic patient. Here we report the case of a 33-year-old woman who developed rapid and aggressive metastatic pulmonary calcification shortly after a living donor kidney transplantation, which induced acute antibody-mediated rejection. The patient's metastatic pulmonary calcification was successfully improved by extensive treatment for graft rejection, the correction of her accompanying primary hyperparathyroidism, and medical treatment with a bisphosphonate and sodium thiosulfate. Aggressive pulmonary calcification is reported as a rare complication seen in patients who have undergone a failed renal transplantation. A failed renal graft and accompanying secondary hyperparathyroidism seem to accelerate metastatic calcification. Most of the patients who develop aggressive pulmonary calcification suffer from the rapid progression of dyspnea and occasionally fever, and they die of respiratory failure. Pulmonary calcification should be considered in a patient developing dyspnea and unexplained pulmonary infiltrate, especially in the context of renal graft rejection; otherwise the prognosis of the patient will be very poor.

Paraneoplastic Hypercalcemia With Metastatic Calcification — Clinicopathologic Studies

Hypercalcemia is a common paraneoplastic syndrome that may result in metastatic calcification. We report here on four autopsy cases with paraneoplastic hypercalcemia with metastatic calcification, to evaluate the clinicopathologic manifestations. All were males, aged 37-63 years old. Primary tumors included one transitional cell carcinoma of the urinary bladder, one multiple myeloma, and two squamous cell carcinomas of the esophagus. Calcium concentrations ranged from 3.3 to 5.9 mmol/L. Chronic hypercalcemia resulted in metastatic calcification. The kidney and stomach were the most vulnerable organs. Only case 1 presented with an increase in plasma calcium above 5 mmol/L (about twice the normal value); the metastatic calcification involved the capillary walls of his lungs, and he died of fulminant pulmonary edema. Our conclusion is that judicious treatment for paraneoplastic hypercalcemia is important with respect to the occurrence of pulmonary edema associated with metastatic calcification.

Calciphylaxis in pediatric end-stage renal disease

Calciphylaxis is a rare, but life-threatening complication of end-stage renal disease (ESRD) that has been reported mostly in adult patients. The exact etiology is unknown, but the disease is commonly associated with a high calcium-phosphorus product and elevated levels of parathyroid hormone (PTH). We herein review the published reports on calciphylaxis in ESRD patients less than 18 years old and report the case of a patient with severe calciphylaxis who presented with lower extremity pain, muscle tenderness and difficulty in walking. The serum PTH was low, and the calcium-phosphorus product was normal. The diagnosis of calciphylaxis was confirmed by a muscle biopsy. Treatment with low calcium peritoneal dialysate and substitution of calcium-based phosphorus binders with sevelamer (Renagel) was unsuccessful. The patient's clinical condition progressed to extensive soft tissue calcification and ulcerating skin lesions. Nine months after the onset of symptoms, the patient died of cardiopulmonary arrest.

Calcium deposition with or without bone formation in the lung

Pulmonary calcification and ossification occurs with a number of systemic and pulmonary conditions. Specific symptoms are often lacking, but calcification may be a marker of disease severity and its chronicity. Pathophysiologic states predisposing to pulmonary calcification and ossification include hypercalcemia, a local alkaline environment, and previous lung injury. Factors such as enhanced alkaline phosphatase activity, active angiogenesis, and mitogenic effects of growth factors may also contribute. The clinical classification of pulmonary calcification includes both metastatic calcification, in which calcium deposits in previously normal lung or dystrophic calcification, which occurs in previously injured lung. Pulmonary ossification can be idiopathic or can result from a variety of underlying pulmonary, cardiac, or extracardiopulmonary disorders. The diagnosis of pulmonary calcification and ossification requires various imaging techniques, including chest radiography, computed tomographic scanning, and bone scintigraphy. Interpretation of the presence of and the specific pattern of calcification or ossification may obviate the need for invasive biopsy. In this review, specific conditions causing pulmonary calcification or ossification that may impact diagnostic and treatment decisions are highlighted. These include metastatic calcification caused by chronic renal failure and orthotopic liver transplantation, dystrophic calcification caused by granulomatous disorders, DNA viruses, parasitic infections, pulmonary amyloidosis, vascular calcification, the idiopathic disorder pulmonary alveolar microlithiasis, and various forms of pulmonary ossification.

Excess PTH in CRF induces pulmonary calcification, pulmonary hypertension and right ventricular hypertrophy

Calcification of the lungs occurs in chronic renal failure (CRF) and may adversely affect both pulmonary and right ventricular function. The present study examined the role of excess parathyroid hormone (PTH) in the genesis of pulmonary calcifications in dogs with experimental CRF and evaluated calcium content of lungs, diffusing lung capacity (DCO), mean pulmonary artery pressure (MPAP), right ventricular pressure (RVP), and right ventricular hypertrophy (RVH) in six normal, six with CRF, and six thyroparathyroidectomized (CRF-PTX) dogs. CRF-PTX animals were maintained normocalcemic and euthyroid. The degree and duration of CRF were not different between the two groups with CRF. The mean value of the serum PTH in CRF dogs was 166 +/- 42 microliters Eq/ml, but was undetectable in CRF-PTX animals. Thallium scan provided evidence consistent with RVH in CRF dogs but not in CRF-PTX animals. Calcium content of lungs was markedly elevated in CRF dogs (7656 +/- 1657 mg/kg dry wt) but modestly increased in CRF-PTX (1057 +/- 117 mg/kg dry wt) as compared to normal (673 +/- 34 mg/kg dry wt). RVP and MPAP were significantly (P < 0.01) higher and DCO significantly lower in CRF dogs than in normal or CRF-PTX animals. These parameters were not different in the latter two group of dogs. In three additional dogs with CRF of one year duration which were followed for an additional year after parathyroidectomy, these abnormalities were corrected.(ABSTRACT TRUNCATED AT 250 WORDS)

Localised pulmonary metastatic calcification associated with pulmonary artery obstruction

BACKGROUND

Metastatic pulmonary calcification, a complication of uraemia and disordered calcium metabolism, may be diffuse or localised. The factors that determine calcium precipitation are complex, but tissue alkalosis is thought to be important. As obstruction of the pulmonary artery theoretically causes local alkalosis a retrospective necropsy study was carried out to examine the relation between metastatic pulmonary calcification and vascular obstruction.

METHODS

Five patients with focal and two with diffuse metastatic calcification in the lungs were identified over eight years. Lungs were studied macroscopically and by light microscopy, haematoxylin and eosin and histochemical stains being used for calcium.

RESULTS

Underlying risk factors for calcification in these patients included renal failure in six and disseminated malignancy in five. In the five patients with localised calcification obstruction of the pulmonary artery by thrombus or tumour was found proximal or adjacent to areas of calcium deposition. In two patients metastatic calcification was confined to a lung with unilateral pulmonary artery thromboembolic occlusion. Calcification was not specifically associated with infarction, pneumonia, or diffuse alveolar damage. Lesions of the pulmonary artery were not seen in the two patients with diffuse bilateral metastatic calcification.

CONCLUSION

In this small series there was a spatial association between pulmonary artery obstruction and localised metastatic calcification. It is proposed that pulmonary artery obstruction alters the microchemical environment of the lung, favouring tissue alkalosis and thereby enhancing parenchymal calcification in patients predisposed to this condition.

Calcification of the heart: a rare manifestation of chronic renal failure

A case is presented in which chronic renal failure led to intense visceral calcification, mainly to the lungs and heart. The discovery of cardiac calcifications on plain chest radiographs is exceedingly rare in renal patients. Punctate calcific deposits with an almost homogeneous distribution throughout the cardiac muscle were the main feature of this case.

Subcutaneous calcifications masquerading as pulmonary lesions in long-term hemodialysis. Review of nodular pulmonary opacities in the population undergoing hemodialysis

Calcification of soft tissue frequently occurs in patients undergoing hemodialysis for chronic renal failure and involves the arteries, eyes, periarticular regions, lungs, heart, abdominal viscera, subcutaneous tissues, and skin. In this report, two such patients are described who presented with apparent pulmonary nodules on their chest roentgenograms obtained on admission. By the use of tomograms and apical lordotic views, both proved to have extrapulmonary calcific deposits in the subcutaneous tissues overlying the upper pulmonary zones. The tendency for these collections to undergo progression, regression, or pseudocavitation is illustrated. Definitive radiographic localization of lesions projecting over the pulmonary fields in patients undergoing hemodialysis is emphasized because of the significantly increased incidence of infection (including tuberculosis), septic embolism, and carcinoma.

Diffuse hepatic calcification as a sequela to shock liver

A 31-yr-old Japanese woman who was on chronic hemodialysis for 3 yr died of intractable congestive heart failure. Three years before death, the patient was in a state of shock for 48 h due to ventricular tachycardia and gastrointestinal bleeding, which was followed by marked elevation of serum transaminase. Four months later, abdominal plain radiography demonstrated diffuse hepatic calcification. At autopsy, microscopic examination of the liver revealed parenchymal necrosis and tiny calcifications in the central to midzonal area of the lobule. Calcification in the degenerative area of the hepatic lobule occurred subsequent to parenchymal ischemia after overt shock that lasted for 2 days. Although a definitive explanation for the calcification was not obtained, it may be related to the disturbances of intracellular Ca2+ homeostasis as a result of ischemic liver injury or it may be related to an elevated calcium-phosphorus product in the uremic state.

Pleural calcification: a type of "metastatic calcification" in chronic renal failure

Pulmonary calcifications associated with chronic renal failure are rare conditions. However, a few such cases have been reported in the literature, and they were regarded as a sign of secondary hyperparathyroidism. Pleural calcification induced by secondary hyperparathyroidism has not been reported in the literature. We report four cases of slow-growing pleural calcification which are considered to have been induced by hyperparathyroidism, in patients undergoing maintenance haemodialysis for chronic renal failure. CT scan was useful for the detection of calcified lesions in the pleura.

Pulmonary calcification and elastic tissue damage in pseudoxanthoma elasticum

A case of pseudoxanthoma elasticum with extensive calcification and elastic tissue damage in the lung is described. This patient had classical skin changes, peripheral arterial calcification, and heart block, but no retinal changes. Hypercalcemia was excluded. Pulmonary involvement is in keeping with the concept of the basic abnormality being in the elastic fibres, and such involvement should be considered as a cause of respiratory symptoms in patients with this condition.

Pulmonary calcification in hemodialyzed patients detected by technetium-99m diphosphonate scanning

Metastatic pulmonary calcification, a well-known complication in patients with chronic disease, has been demonstrated postmortem in patients with a negative chest X-ray. Recently, scintigrams with bone-seeking radionuclides have been used to detect such subclinical pulmonary calcium deposits. We describe 23 patients on maintenance hemodialysis with no evidence of pulmonary calcification on chest X-ray who were prospectively studied by lung scanning with a bone-seeking radionuclide and pulmonary function testing. Of the 23 patients, 14 (61%) had a positive technetium-99m diphosphonate (99mTc-DP) scan (group 1). These patients were on dialysis 38 +/- 5 months compared with 12 +/- 4 months in 9 patients with a negative scan (group 2) (P less than 0.01). Age, sex, blood pressure, hematocrit, serum calcium, phosphorous, bicarbonate, magnesium, and calcium X phosphorus product, as well as parathyroid hormone level did not differ between the two groups. Of 10 group-1 patients tested, 7 had abnormal pulmonary diffusion capacity compared with non in 5 group-2 patients tested (P = 0.014). Histologic examination of the lung in 1 group-1 patients who expired revealed calcification (amorphous on X-ray diffraction), whereas none was found in 1 group-2 patients autopsied. These observations suggest that in patients on maintenance hemodialysis, pulmonary scanning with 99mTc-DP is a sensitive method for detecting pulmonary metastatic calcification, which may be associated with an abnormality in pulmonary diffusion capacity.

Metastatic visceral calcification identified by bone scanning

The scintigraphic abnormalities with radionuclide bone scanning observed in a patient with metastatic breast carcinoma associated with hypercalcaemia are described. Abnormal uptake of 99mTc-pyrophosphate was noted in the lungs, stomach, myocardium, kidneys, and thyroid, indicating metastatic visceral calcification. A scan performed 72 h later when she was normocalcaemic showed marked reduction in the accumulation in the myocardium and thyroid. In a further scan, 18 months later, no extraosseous uptake was present. A review of 26 reported cases of visceral metastatic calcification with scintigraphic abnormalities indicates that the changes in this patient were more widespread and that in only two of the previous cases similar total resolution had been observed. The reasons for the discrepancy between the incidence of visceral calcification on autopsy and on scintigraphic examination are discussed in relation to the aetiological factors. It is concluded that bone scanning offers a useful method for identifying visceral calcification, except when associated with uncomplicated renal failure, and is valuable in detecting this abnormality in patients with hypercalcaemia and in the assessment of response to therapy.

Pulmonary metastatic calcification with respiratory insufficiency in patients on maintenance haemodialysis

A uraemic patient undergoing chronic haemodialysis developed diffuse metastatic pulmonary calcification and died from acute respiratory insufficiency after renal transplantation. Thirteen similar cases previously published are reviewed, with emphasis on the clinical and anatomical features of such calcinosis. The pathogenesis of this calcification in patients on maintenance haemodialysis and some rules for its prevention are discussed.

Pulmonary calcinosis

The clinical and pathological features are described of a case of pulmonary calcinosis complicating cystic disease of the renal medulla. A histopathological study of the lung revealed calcification in the alveolar walls and in the blood vessels, predominantly in the pulmonary veins and venules. The calcified deposits were also studied by electron microscopy, and appearances suggestive of active growth of the deposits were recognised. Chemical analysis of the lung revealed a calcium content some 55 times greater than that of a normal lung. There was a five-fold increase in magnesium content. Reference is made to the literature demonstrating that the chemical composition of metastic calcification differs according to whether it is visceral or non-visceral in type.

Pulmonary calcifications in a child with renal failure

A chronically azotemic 2 6/12 boy developed diffuse, bilateral pulmonary calcification. The radiographic features and pathologic mechanism of such pulmonary calcification is discussed.