A 49-year-old man was referred to our hospital with progressively worsening shortness of breath, dry cough and weight loss of approximately 10 kg. Three weeks prior to admission, the patient had presented to another hospital and was treated with antibiotics without improvement.
His past medical history was remarkable for tobacco addiction and alcohol abuse. He also had used cocaine up to 2 years before presentation. He did not report having any kind of environmental exposures or pets.
On admission, his blood pressure was 140/80 mmHg. His temperature was 38  C, and auscultation of his chest revealed diminished breath sounds and wheezing. The oxygen saturation (SpO2) was 98% on room air.
Notable laboratory findings included the following: a white blood cell count of 13,000/mL, a platelet count of 439,000/mL, and a hemoglobin of 16.7 g/dL. HIV serology, antinuclear antibody (ANA) and anti-neutrophil cytoplasmic antibody (ANCA) were negative. The prostate-specific antigen (PSA) level was lower than 4.0 ng/mL.
Pulmonary function tests revealed a severe non-obstructive defect, and a chest CT scan showed multiple lung cysts that predominated in the lower lobes (Fig. 1). A bronchoscopy was performed, and no endoluminal or mucosal lesions were observed. A bronchoalveolar lavage (BAL) culture was negative for bacterial infection, Mycobacterium tuberculosis (and nontuberculous mycobacteria) infection and fungal infection. The cytological examination did not find atypia, and CD1a immunostaining of the BAL cells was also negative.
The patient was treated with intravenous broad spectrum antibiotics and steroids for 14 days, showing moderate improvement of his respiratory symptoms. He was discharged from the hospital and readmitted three weeks later with dyspnea and productive cough with purulent sputum.
He was alert, tachycardic and tachypneic. Chest auscultation revealed diminished breath sounds and bilateral wheezing. The SpO2 was 85% on room air.
Laboratory findings included the following: a white blood cell count of 41,500/mL, a blood glucose of 331 mg/dL, and a C reactive protein (CRP) level of 13.9 mg/dL.
A new chest CT scan demonstrated an increased number of cysts (some of which were filled with mucus), bilateral ground glass opacities and consolidation.
A diagnosis of nosocomial pneumonia was made. The patient was started on antibiotic therapy with vancomycin and piperacillin-tazobactam, but his clinical condition deteriorated rapidly. He was intubated and mechanically ventilated. A second bronchoscopy was performed, and transbronchial biopsies were obtained.
The biopsy specimen revealed a small fragment of lung parenchyma infiltrated by large cells, some of which had prominent nucleoli and eosinophilic cytoplasm, showing gland formation areas and focal necrosis. The tumor cells were CK-20-positive, villin-positive, CK7-negative and TTF1-negative. The patient was diagnosed with metastatic colorectal cancer.
The patient died on the 4th day after admission.
High resolution CT showing multiple cysts, which markedly vary in size, in the lower lobes and nodules that tend to cavitation.