Invasive mucinous adenocarcinoma of the lung presenting as a large, thin-walled cyst: A case report and literature review.

Invasive mucinous adenocarcinoma (IMA), formerly referred to as mucinous bronchioloalveolar carcinoma, is a rare variant form of invasive adenocarcinoma and is radiologically characterized by dense pneumonic consolidation, ground-glass opacity and nodules. By contrast, large, thin-walled cysts are rare. We herein report the case of a 75-year-old man with IMA presenting as a large, irregularly shaped cystic lesion. The histological diagnosis was based on specimens obtained during a bronchoscopy. The patient underwent lobectomy followed by anticancer chemotherapy for residual intrapulmonary metastases. Of note, the small metastatic nodules transformed into cystic lesions with thin walls and fused, forming a large, multiloculated cystic lesion. Typical pneumonic consolidation appeared in the pericystic parenchyma later during the clinical course. The available literature on this rare radiological manifestation was also reviewed and discussed. Clinicians should be aware of thin-walled cystic lesions as they may be an unusual radiological finding in IMA.

Hemoperitoneum Secondary to Rupture of a Hepatic Metastasis from Small Cell Lung Cancer during Chemotherapy: A Case with a Literature Review.

A 65-year-old man was diagnosed with small cell lung cancer with multiple liver metastases. Three days after initiating chemotherapy, he experienced abdominal discomfort with hypotension. Computed tomography revealed a ruptured liver metastasis and the presence of hemorrhagic ascites. Transcatheter arterial embolization to the appropriate hepatic artery in concomitant with supportive therapies successfully stabilized his condition. Unlike with hepatocellular carcinoma, the rupture of a liver metastasis and associated hemoperitoneum is very rare in patients with lung cancer. We comprehensively reviewed the literature and found 10 similar cases with this serious condition. Physicians should therefore be aware of the risk of hemoperitoneum caused by ruptured liver metastases in patients with lung cancer.

Pulmonary Mycobacterium avium infection demonstrating unusual lobar caseous pneumonia.

Mycobacterium avium complex (MAC) infection is a major medical concern in Japan because of its increased prevalence and associated mortality. A common radiological feature in pulmonary MAC infection is a mixture of two basic patterns: fibrocavitary and nodular bronchiectatic; however, lobar consolidation is rare. We report an 83-year-old man with lobar caseous pneumonia caused by pulmonary MAC infection. Radiological findings were predominantly composed of dense lobar consolidation and ground-glass opacity. A diagnosis was made in accordance with the clinical and microbiological criteria set by the American Thoracic Society. A histological examination of lung specimens obtained by using a bronchoscope revealed a caseous granulomatous inflammation with an appearance of Langhans cells. The patient was treated using combined mycobacterium chemotherapy with an initial positive response for 6 months; however, the disease progressed later. We suggest that an awareness of lobar pneumonic consolidation as a rare radiological finding in pulmonary MAC infection is important.