Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Multifocal micronodular pneumocyte hyperplasia (MMPH) in tuberous sclerosis
- Radiologic Findings
- Fig 1-2. Chest CT scans show multifocal small nodules and GGNs in both lungs.
Fig 3-4. Chest CT scans show multifocal osteosclerotic change in T-spines.
Fig 5. Enhanced chest CT scan demonstrates a subendocardial focal fatty deposit in the interventricular septum.
- Brief Review
- Tuberous sclerosis complex (TSC) is an inheritable multiorgan disease. MMPH is a manifestation of TSC with a hamartomatous process of the lung that exhibits multiple tiny pulmonary nodules. Pathologically, it is characterized by the proliferation of type II pneumocystis along the alveolar septa. MMPH can occur in patients with or without lymphangioleiomyomatosis (LAM), predominantly in female patients.
The clinical manifestations resulting from isolated MMPH are dyspnea, cough, and mild to moderate hypoxemia. The clinical course of MMPH is usually not progressive and treatment is unnecessary.
Radiologically, MMPH presents as multiple nodules on CT. Nodules are 1-8mm in diameter and are diffusely scattered throughout the lung in a random distribution with regard to the secondary lobule. The differential diagnosis should also include a miliary granulomatous infection, Langerhans cell histiocytosis, hematogenous metastasis and multiple atypical adenomatous hyperplasia/adenocarcinoma in situ.
Additionally, the presence of well-circumscribed foci of homogeneous fat attenuation in the myocardium of patients with TSC was seen in the majority of patients with TSC usually located in the interventricular septum and the left ventricular wall. Fatty foci in patients with TSC appear to have unique CT characteristics with respect to location, attenuation, focality, absence of enhancement, and absence of invasive behavior that most closely resembles that of lipomas seen in other parts of the body.
In this patient, brain axial fluid-attenuation inversion-recovery image demonstrates focal areas of high signal intensity and enhanced CT image shows well-defined mass-like lesion with fat attenuation in the liver, compatible with angiomyolipoma. Considering all these features in the patient, these could be thought as manifestation of TSC.


- References
- 1. Ristagno RL, Biddinger PW, Pina EM, Meyer CA. Multifocal micronodular pneumocyte hyperplasia in tuberous sclerosis. AJR Am J Roentgenol 2005; 184:S37-39.
2. Adriaensen ME, Schaefer-Prokop CM, Duyndam DA, Zonnenberg BA, Prokop M. Fatty foci in the myocardium in patients with tuberous sclerosis complex: common finding at CT. Radiology 2009; 253:359-363.
3. Von Ranke FM, Faria IM, Zanetti G, Hochhegger B, Souza Jr AS, Marchiori E. Imaging of tuberous sclerosis complex: a pictorial review. Radiol Bras. 2017 Jan/Fev;50(1):48–54
- Please refer to
- Case 1124 Case 1050
-
- Keywords