Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Multifocal micronodular pneumocyte hyperplasia (MMPH)
- Radiologic Findings
- Figure 1. Chest PA shows nodular opacity in left upper lung field.
Figure 2-3. CT scans show well-defined subsolid nodule in left upper lobe apicoposterior segment (25 mm) and other multiple smaller GGOs in bilateral lungs (5-13 mm).
- Brief Review
- MMPH is a rare pulmonary disorder that can be associated with Tuberous Sclerosis (TS). It is characterized by multicentric, well-demarcated nodular proliferation of type II pneumocytes along alveolar septa. Since the hamartomatous nature of micronodular epithelial proliferations has been emphasized, the terms multiple adenomatoid tumors, acinar atypical adenomatoid proliferation of epithelium, and micronodular hyperplasia of type II pneumocytes have been proposed as being more descriptive names. Recently, these lesions have come to be commonly called MMPH, taking their pathogenesis and locations into account. MMPH can occur in patients with or without lymphangioleiomyomatosis (LAM), predominantly in female patients. Clinically, patients with MMPH may present with dyspnea, cough, and mild to moderate hypoxemia. Unlike with pulmonary LAM, treatment is usually unnecessary because MMPH does not appear to be fatal and progressive.
At thin-section CT, multiple tiny nodules (3-10 mm) or numerous miliary nodules (1-3 mm) are diffusely scattered throughout the lung in a random distribution. Although differentiation of MMPH from miliary metastatic or granulomatous disease is difficult, MMPH should be considered in the differential diagnosis when multiple tiny pulmonary nodules are present in patients with TS.
This patient did not know about TS. After pathologic confirmation of lung lesion, TS was confirmed in gene test.
- Please refer to
Case 979, Case 1124, -
KSTR imaging conference 2018 Spring Case 15,
- References
- 1. Ross L. Ristagno, Paul W. Biddinger, Elsira M. Pina and Cris A. Meye, Multifocal Micronodular Pneumocyte Hyperplasia in Tuberous Sclerosis. American Journal of Roentgenology. 2005;184: S37-S39
2. Umeoka S, Koyama T, Miki Y, Akai M, Tsutsui K, Togashi K., Pictorial review of tuberous sclerosis in various organs. Radiographics. 2008 Nov-Dec;28(7):e32
- Keywords
- lung, multiple micronodules, MMPH,