Fetal lung interstitial tumor

Fetal lung interstitial tumor (FLIT) is a recently proposed designation for a rare primary lung mass detected prenatally or when the patient is up to 3 months old.

Epidemiology

Fetal lung interstitial tumors have a slight predominance in boys .

Pathology

Fetal lung interstitial tumors were first classified by Dishop et al in 2010, after documentation of 10 cases of circumscribed solid to mixed-solid and microcystic lesions with unique pathologic and immunohistologic features distinct from pleuropulmonary blastomas .

Clinical presentation

It can present with varying degrees of respiratory distress, with moderate-to-severe distress developing in infants .

Radiographic features

Findings on chest radiographs are nonspecific and may include a volume-occupying lobar opacity that displaces the mediastinal structures. Fetal lung interstitial tumors is more characteristically homogeneous and lacks locally aggressive features.

CT

Fetal lung interstitial tumors are low-attenuating masses of uniform attenuation with well-circumscribed margins and no chest wall invasion.

MRI
  • T2: hyperintense intrathoracic mass that exerts local mass effect