Miliary brain metastases from lung adenocarcinoma as non- enhancing lesions on MRI: a case report and literature review

Abstract

Miliary dissemination is common in tuberculosis, but is an extremely rare form of brain metastasis. It is mainly found in patients with primary lung cancer (small cell and adenocarcinoma). Here, we presented a case of miliary metastases of lung adenocarcinoma to the brain without lesion enhancement on MRI after administration of contrast. A 38-year-old Chinese male was diagnosed with lung adenocarcinoma and received chemotherapy monthly for 6 months. At one month after completion of chemotherapy, the patient presented with headache, dizziness, and vomiting. Brain MRI revealed numerous, disseminated, tiny, rounded cystic high-signal intensity lesions on T2-weighted images, and low-signal intensity lesions on T1-weighted images, with no enhancement. In addition, a high signal on T2-weighted images and uneven enhancement with contrast in the hypophysis were noted. A right frontal lobe biopsy revealed miliary metastases originating from primary lung adenocarcinoma, which was consistent with the pathological finding of a bronchial biopsy. However, the patient and his family requested supportive treatments only, and he died 3 months after the diagnosis. In summary, this case indicates that when imaging findings are not consistent with the most likely cause of miliary brain metastasis, a biopsy is necessary to make a definitive diagnosis.

MRI sequencing of brain metastasis from lung malignancy: Literature review

“…Cortical involvement should provoke the investigation of additional conditions, such as a primary brain tumor. 5,11,12…”

Miliary cerebral metastases: prevalence and radiological findings

“…1, 3 However, these disseminated lesions in the context of brain metastases originate from various primary cancers, including but not limited to breast, lung, and gastrointestinal tumors. [4][5][6][7][8][9] Despite the significant burden that brain metastases impose on patients' quality of life and survival, the unique subset of miliary cerebral metastases remains poorly understood. 10, 11 The exact incidence of miliary cerebral metastases is uncertain, primarily due to its rarity, and it is thought to represent only a small fraction of all brain metastases.…”