Miliary cerebral metastases
Miliary cerebral metastases (or carcinomatosis encephalitis ) is a rare form of cerebral metastastic disease 1.
As with the use of miliary description in other conditions, the appearances are of innumerable tiny, punctate nodules, in this case scattered throughout the brain. The nodules may be observed in the cerebral cortex, basal ganglia, thalami, brainstem and cerebellum. The nodules occur in a perivascular distribution, especially at the grey-white matter interface.
Of the limited number of reported cases, the primaries responsible include; lung, malignant melanoma and breast carcinoma 3,4.
The nodules are essentially invisible on non-enhanced CT. Following intravenous contrast a small proportion of the nodules enhance and are subtly identified.
The nodules have mild high T2 and FLAIR signal, being unobservable on T1. Avid homogeneous enhancement following contrast is the key sequence in illustrating the extent and distribution of disease.
Treatment and prognosis
The prognosis following diagnosis is dire. Clearly no surgical option is present and treatment is with chemo-radiotherapy.
History and etymology
It was originally documented in 1951 by Madow and Alpers 2.
- 1. Nemzek W, Poirier V, Salamat MS et-al. Carcinomatous encephalitis (miliary metastases): lack of contrast enhancement. AJNR Am J Neuroradiol. 1993;14 (3): 540-2. AJNR Am J Neuroradiol (abstract) - Pubmed citation.
- 2. MADOW L, ALPERS BJ. Encephalitic form of metastatic carcinoma. AMA Arch Neurol Psychiatry. 2004;65 (2): 161-73. Pubmed citation.
- 4. Iguchi Y, Mano K, Goto Y et-al. Miliary brain metastases from adenocarcinoma of the lung: MR imaging findings with clinical and post-mortem histopathologic correlation. Neuroradiology. 2007;49 (1): 35-9. doi:10.1007/s00234-006-0152-6 - Pubmed citation
- 3. Bekiesińska-Figatowska M, Kuczyńska-Zardzewiały A, Klepacka T et-al. Miliary brain metastases from papillary adenocarcinoma of the lung - unusual MRI pattern with histopathologic correlation. Pol J Radiol. 2013;78 (3): 57-60. Free text at pubmed - Pubmed citation.