Diffuse pulmonary ossification associated with metastatic melanoma of the lung

A case with advanced diffuse pulmonary ossification is described. The patient underwent surgical treatment of a malignant nodular melanoma of the right shoulder followed by postoperative cytostatic therapy for 6 months. He developed renal insufficiency and pulmonary infiltrates 3 years after the operation. Two metastases into the lung were operated 4 years after extirpation of the melanoma. Histopathological findings revealed two major metastases of a malignant amelanotic melanoma and multiple tumour thromboses in lymphatic and venous vessels. Severe interstitial lung damage including diffuse pulmonary ossification and focal interstitial fibrosis was noted. Morphometric measurements of ossified nodules revealed increased ossification in fibrotic lung areas. Immunohistology for differentiating immunoglobulins and lymphocytic subpopulations was insuspicious. The findings suggest that diffuse intraalveolar ossification is probably not related to pulmonary congestion.