Objective:

To investigate the CT and PET/CT imaging findings of lung primary small cell neuroendocrine carcinoma (LSCNC)

so as to improve its diagnostic accuracy.

Methods:

The imaging and clinicopathologic data of sixty-one patients with LSCNC confirmed by pathology were retrospectively analyzed and related literatures reviewed. All cases were perform

ed with abdomen-thorax CT plain and enhanced scan and ten with two-phase whole body

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F-FDG PET/CT examination.

Results:

On CT

of the sixty-one tumors

forty-four were central type and the others were peripheral. Fifty-five cases appeared irregular shape with lobular

four round/ovoid shape and two multinodular shape. Thirty-three had clear boundary and twenty-eight unclear. Sixty cases except one showed inhomogeneous density with cyst degeneration and necrosis

one with punctate calcifications. Fifty-eight werewith mediastinal or hilar lymphadenectasis and necrosis

seventeen with pleural or pericardial effusion

sixteen with obstructive atelectasis or pneumonia

three with nearby pulmonary artery pressed and two with pleural indentation. Eighteen were combined with pulmonary metastasis

ten liver metastasis

seven bone metastases

four brain metastases

three adrenal metastasis and one splenic metastasis. After enhanced scanning

fifty-three cases showed moderate reinforcement

eight marked enhancement

and it could clearly show the relations between lung lesion and mediastinal structure. On early-phase

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F-FDG PET/CT

ten cases of lung tumors

hilar or mediastinal lymph nodes and distant metastatic lesions were showed significantly high metabolism

the metabolism of the lesions remain elevated after two hours delay imaging

suggesting lung malignant tumors with hilar or mediastinal lymph nodes metastasis and distant metastasis.

Conclusion:

The enhanced CT and two-phase PET/CT examinations have important clinical value for diagnosis and differential diagnosis of LSCNC.