multifocal micronodular pneumocyte hyperplasia (MMPH)

Multifocal micronodular pneumocyte hyperplasia (MMPH) is a rare benign hamartomatous proliferation of type II pneumocytes and is seen in association with tuberous sclerosis (TS). It can occur with or without concurrent lymphangiomyomatosis.

Radiographic features

HRCT / Contrast CT Chest

Seen as random faint but relatively well defined small (1-10 mm ) nodular lung parenchymal densities in patients with tuberous sclerosis. These tends to be diffusely scattered throughout the lung in a random distribution with regard to the secondary lobule .

Treatment and prognosis

Unlike lymphangiomyomatosis, MMPH is not progressive and therefore treatment is not required .

History and etymology

It was first described by Popper et.al in 1991 .

Differential diagnosis

General imaging differential considerations include