A 66-year-old man was referred to our hospital for evaluation of mild fever, blood-streaked sputum and chest discomfort for 7 days prior to admission. At five months before admission, a cough with minimal episodes of bloody sputum had developed. At that time, chest radiographs were said to be unremarkable. He denied having shortness of breath, wheezes, weight loss or night sweats. He works as a fisherman and has not smoked for 1 year but has a 30-pack-year history of tobacco use. His medical history was significant for cholecystectomy and laminoplasty for herniation of nucleus pulposus five years previously. His family history was noncontributory.
On presentation, the patient appeared to be in no distress, relatively. His blood pressure was 110/70 mmHg; heart rate 78 beats /min; respiratory rate 23 breaths /min; body temperature 37.60 C. Examination of the lung revealed slightly reduced breath sounds over the right lower lung. Cardiac examination revealed a regular rhythm without murmurs. Findings of the abdominal examination were normal and the extremities were without clubbing, cyanosis or edema.
The laboratory tests were as follows: WBC count, 15.7x103/uL with 78% neutrophils, 13% lymphocytes, 7% monocytes, 1% eosinophils and others 1%; Erythrocyte sedimentation rate, 44 mm/h; hemoglobin, 14.4 g/dL; hematocrit, 41.4%; platelet count, 313x103/uL. Other laboratory findings including liver function, blood glucose level, renal function, electrolytes and urine microscopy, were all within normal limits. Arterial blood gas analysis on room air revealed a pH of 7.459, Pco2 of 36.8 mmHg and Po2 of 76.9 mmHg. The chest radiograph obtained at the time of admission showed a round mass in the right lower lobe (Figure 1). The chest CT scan performed at the referring hospital confirmed the presence of a 4x4 cm-sized, smoothly marginated, soft tissue density with central lower density in the right lower lobe.
An initial diagnosis of subclinical infectious disease or necrotizing solitary mass was made; the patient was treated with empirical antibiotics. However, mild fever and blood-tinged sputum persisted despite the use of broad-spectrum antibiotics. The lesion looked larger on a chest radiograph. The patient still felt well, apart from the mild fever. Sputum culture findings were negative for bacteria and fungus. Tuberculosis smear was negative and cultures were pending. Sputum cytology testing results were also negative.
The chest CT scan documented a slightly increased size of the mass, with more increased extent of the central low density compared with the previous chest CT and no mediastinal or hilar lymphadenopathy (Figure 2). The patient declined bronchoscopy and therefore, percutaneous fine needle aspiration was performed. Only blood without pus was aspirated and the results of aspirates were negative for routine bacterial Gram's stain and culture, including acid-fast bacilli and fungi, thus ruling out infectious process.
To define the exact etiology of the radiologic findings, thoracoscopic wedge biopsy of the left lower lobe demonstrated the mass to be contained within the lateral basal segment and the medial basal segment of the left lower lobe. On gross section, the mass was 10x9x7 cm in size, sharply circumscribed and smoothly contoured. It had no involvement to the chest wall and no endobronchial component, but extended centrally to hilar areas. Light microscopic examination demonstrated a tumor composed of malignant epithelial components and mesenchymal components. The carcinomatous components consisted of poorly differentiated squamous cell carcinoma and the sarcomatous components were considered chondroid sarcoma in the light of microscopic findings (Figure 3). Light microscopic immunohistochemical analysis showed that the tumor cells in the carcinomatous component reacted with anti-epithelial membrane antigen (EMA) antibody and the tumor cells in the sarcomatous component reacted with anti-vimentin antibody (Figure 4). He underwent workup for distant metastasis, the findings of which were unremarkable. Therefore, left lower lobectomy was performed with lymph node dissection. There was no microscopic evidence of lymph node metastases making this the international TNM stage lb (T2N0M0) lesion.
After surgical resection, mild fever and blood-tinged sputum disappeared. His postoperative course was uneventful without major complication. At 6-month follow-up, there remains no evidence of metastasis or tumor recurrence
The chest CT shows a large cystic mass with central low density and no mediastinal or hilar lymphadenopathy.