Adenosquamous carcinoma of the lung: CT-pathological correlation.

Aim: To correlate CT morphological features and histopathological findings of adenosquamous carcinoma of the lung.

Materials And Methods: In all, 29 patients underwent contrast-enhanced CT of an adenosquamous carcinoma of the lung, followed by resection of the cancer. Correlations between CT morphological and histopathological features were evaluated, including location, characteristics of margins, attenuation and the presence of necrosis.

Results: The tumour was peripheral in 21 (72%) and central in 8 (28%) cases. The tumours varied in size from 1.1cm to 11.0cm (mean 3.8cm); 20 (69%) appeared as heterogeneous masses and 9 (31%) as homogeneous masses. The most common CT features were lobulation in 27 (93%), pleural tail in 22 (76%), spiculation in 17 (59%), necrosis in 15 (52%) and vessel convergence in 13 (45%). Among the 21 peripheral tumours, 14 (67%) showed intratumoural necrosis and 17 (81%) were heterogeneous. Among the 8 central tumours, only 1 (12.5%) showed intratumoural necrosis and 5 (62.5%) were homogeneous. These CT features corresponded mainly to solid tumour growth, which was composed of both squamous cell carcinomatous and adenocarcinomatous tissue.

Conclusion: Adenosquamous carcinoma of the lung is shown to be characteristically a solid, lobulated nodule or mass, more commonly peripheral than central. After intravenous injection of positive contrast medium, CT shows that the peripheral lesions are usually of heterogeneous soft-tissue attenuation.