OBJECTIVE: This study was designed to evaluate follow-up results in terms of patient prognosis for malignant pulmonary nodules depicted as pure ground-glass opacity (GGO) lesion observed at high-resolution CT (HRCT). MATERIALS AND METHODS: Surgical removal for malignant GGO nodules was accomplished in 58 patients (26 men, 32 women; mean age, 57 years; age range, 29-78 years). Patient prognoses were assessed by patient clinical status and the presence of changes in nodule size determined after a follow-up HRCT examination. Differences in patient prognoses were compared for nodule number, size, surgical method, change in size before surgical removal, and histopathological diagnosis by use of Fisher's exact test and Pearson's chi-squared test. RESULTS: Of the 58 patients, 40 patients (69%) were confirmed to have a bronchioloalveolar carcinoma (BAC) and 18 patients (31%) were confirmed to have an adenocarcinoma with a predominant BAC component. Irrespective of nodule size, number, treatment method, change in size before surgical removal and histopathological diagnosis, neither local recurrence nor a metastasis occurred in any of these patients as determined at a follow-up period of 24 months (range; 12-65 months). Of 14 patients with multiple GGO nodules, all of the nodules were resected without recurrence in six patients. In the remaining eight patients, the remaining nodules showed no change in size in seven cases and a decrease in size in one case as determined after a follow-up CT examination. CONCLUSION: Prognoses in patients with pure GGO malignant pulmonary nodules are excellent, and not significantly different in terms of nodule number, size, surgical method, presence of size change before surgical removal and histopathological diagnosis.
Adenocarcinoma/pathology/radiography/surgery ; Adenocarcinoma, Bronchiolo-Alveolar/pathology/radiography/surgery ; Adult ; Female ; Humans ; Lung Neoplasms/pathology/*radiography/surgery ; Male ; Middle Aged ; Multiple Pulmonary Nodules/pathology/*radiography/surgery ; Prognosis ; Solitary Pulmonary Nodule/pathology/*radiography/surgery ; *Tomography, X-Ray Computed ; Young Adult

Clear cell tumor of the lung is a rare and very unusual benign pulmonary tumor. As clear cell tumor of the lung contains abundant cytoplasmic glycogen, this tumor is called "sugar tumor". We report a case of sugar tumor in a 64-yr-old man presenting as a round pulmonary nodule. On dynamic computed tomography (CT) scans, the solitary pulmonary nodule showed early wash-in enhancement with an early washout pattern like a lung malignancy. The patient underwent wedge resection for the tumor. Pathologic examination, including immunohistochemical studies, revealed that the nodule was a benign clear cell tumor, so-called "sugar tumor". Because only a small number of cases have been reported previously, clinical aspects, radiological characteristics on dynamic contrast-enhanced CT, and differential diagnosis of the tumor are not well established. Herein we present a clear cell tumor of the lung and discuss the clinical, radiological, and pathological features of the tumor.
Antigens, Neoplasm/metabolism ; Diagnosis, Differential ; Humans ; Lung/radiography/surgery ; Lung Neoplasms/diagnosis/pathology/*radiography ; Male ; Middle Aged ; Neoplasm Proteins/metabolism ; Perivascular Epithelioid Cell Neoplasms/diagnosis/pathology/*radiography ; Solitary Pulmonary Nodule/diagnosis/pathology/*radiography ; *Tomography, X-Ray Computed