Mucoepidermoid carcinoma of the lung: high-resolution CT and histopathologic findings in five cases

The purpose of this study was to characterize the high-resolution computed tomography (HRCT) findings of mucoepidermoid carcinoma of the lung and correlate them with the histopathological features.

The study included five patients with pathologically proven mucoepidermoid carcinoma who underwent HRCT before treatment. The HRCT findings were then compared with the histopathological features in all patients.

The HRCT images showed lesions in the central lung in four patients and in the peripheral lung in one. All the lesions were well defined nodules or masses with a smooth margin. The contour of the tumours was oval (n=3), round (n=1) or lobulated (n=1). The contrast-enhanced CT images showed marked heterogeneous enhancement with foci of relatively low attenuation in four of the five lesions and mild heterogeneous enhancement in the other lesion. There was an admixed distribution of areas that are heterogeneous in the densities of blood vessels, as highlighted by immunohistochemical staining of CD31. Most mucin-secreting areas of the tumours showed more densely distributed blood vessels, mostly capillaries, in between tumour cell nests, whereas other areas did less. All five patients in our series underwent lobectomy plus lymph node dissection or sampling. All the patients are alive without evidence of disease an average of 50.4 months after surgery (range, 15-82 months; median, 57 months).

Mucoepidermoid carcinoma of the bronchus is often visualized as marked heterogeneous contrast enhancement on HRCT images. The results of this study suggest that the presence of abundant microvessels, detected immunohistochemically by microscopic examination, affects the enhancement pattern on HRCT.