[Squamous cell carcinoma of the lung with high CT number, but without calcification].

Squamous cell carcinoma of the lung was diagnosed in a 64-year-old man. Chest roentgenographic and tomographic examinations did not show areas of high-density in the tumor, but chest CT scan showed diffuse, scattered, high-density nodules in the tumor. Histologic examination did not show calcification, and calcium staining (Kossa method) was negative. Examination of the thin-slice CT, the soft X-ray film, and the resected slice of the lung indicated that the high-density nodules seen in the tumor on the chest CT scan corresponded to markedly fibrotic lesions with severe anthracosis. This case shows that high-density areas on a CT scan may reflect non-calcified lesions.

[Pulmonary malignant lymphoma associated with bilateral diffuse linear, reticular, and consolidated shadows].

A 72-year-old asymptomatic man was admitted to our hospital with abnormal chest radiographic findings: bilateral diffuse linear, reticular, and consolidated shadows. Malignant lymphoma (diffuse small-cell B-cell lymphoma) was diagnosed histologically after an open lung biopsy and was confirmed by a genetic examination. The lymphoma cells had infiltrated widely in various regions of the lung, including the alveolar spaces and walls, the bronchial and vascular spaces, and the pleura. This diffusion of the lymphoma cells might have accounted for the chest X-ray findings. Malignant pulmonary lymphoma should be included in the differential diagnosis patients with diffuse linear, reticular, and consolidated shadows on chest X-ray films.

Increased procoagulant and antifibrinolytic activities in the lungs with idiopathic pulmonary fibrosis.

To elucidate the pathophysiology of idiopathic pulmonary fibrosis (IPF), we examined procoagulant (tissue factor:TF), fibrinolytic (tissue type plasminogen activator:t-PA and urokinase type plasminogen activator:u-PA) and antifibrinolytic (plasminogen activator inhibitor-1:PAI-1 and PAI-2) activities in bronchoalveolar lavage (BAL) supernatant fluids and BAL cell lysates obtained from IPF patients. The results indicated that TF levels in BAL supernatant fluids from IPF patients were higher than those of normal subjects, especially in patients with progressive disease, suggesting that TF levels in the lung correlate with disease activity. PAI-1 levels in BAL supernatant fluids were significantly higher in IPF patients than in normal subjects (1.7 +/- 4.1 vs 0 ng/mg protein). PAI-2 levels in BAL cell lysates were also significantly higher in IPF patients than those in normal subjects (14.4 +/- 12.2 vs 3.0 +/- 3.0 ng/mg protein). However, u-PA levels in both BAL supernatant fluids and BAL cell lysates did not differ between the two groups. These observations suggest that u-PA inhibition exceeded u-PA activity in alveolar lining fluid resulting in an antifibrinolytic condition. Immunohistochemical analysis showed that TF was intensely stained in cuboidal epithelial cells and PAIs were positively stained in alveolar macrophages (AMs) and cuboidal epithelial cells, suggesting that cuboidal epithelial cells as well as AMs contribute to the increased procoagulant and antifibrinolytic activities in the lungs of IPF patients.

[A case of necrotizing sarcoid granulomatosis].

A 60-year-old woman was admitted to our hospital because of progressive cough and chest pain for 2 months. She also complained of exertional dyspnea. Bilateral diffuse infiltlative shadows were found on the chest roentogenogram. Ground-glass opacity in the middle lobe and lingula, and subpleural patchy consolidation were seen on the computed tomogram of the chest. Arterial oxygenation and diffusing capacity were low. The level of angiotensin-converting enzyme in serum was normal, but that of lysozyme was high. In the BAL (broncho-alveolar lavage) fluid, total cell count and the number of lymphocytes were high, and the CD 4/8 ratio of the lymphocytes was high. Open lung biopsy revealed numerous confluent sarcoid granulomas with necrosis, which strongly correlated with severe vasculitis. After necrotizing sarcoid granulomatosis was diagnosed, prednisolone was administered, which resulted in improvement of symptoms and disappearance of chest-radiograph shadows. Necrotizing sarcoid granulomatosis may be seen as a variant type of sarcoidosis. However, clinical findings including the chest-radiograph shadows and clinical course of this case differ from those of ordinary sarcoidosis. These clinical findings can be attributed to severe vasculitis, as revealed by histological examination.