Miliary brain metastases from occult lung adenocarcinoma: Radiologic and histopathologic confirmation

Abstract

“Miliary brain metastases”, also termed as “Carcinomatous encephalitis”, are an extremely rare form of cerebral metastasis. Here in this article, we report a 52 year-old male patient with miliary brain metastases originating from occult lung adenocarcinoma. There were no significant findings on his initial physical and neurological examinations except limited cooperation. Brain computed tomography revealed edematous regions at the inferior sections of both parietal lobes. Then after, the contrast-enhanced magnetic resonance imaging revealed innumerable multi-dimensional lesions associated with surrounding edema on T2-weighted images. The proton magnetic resonance spectroscopy revealed increases in the choline and lipid peaks with decreased N-acetylaspartate in a similar manner with metastatic brain tumors. Histopathological findings pointed out that malignant epithelial tumor metastasis were originating in primary lung adenocarcinoma. Despite the advances in technical equipments and medical knowledge, miliary metastatic brain tumors are quite rare and the differential diagnosis is difficult. Our aim in this article was to present this rare case in which the lung was thought to be the primary focus; and outline the radiological characteristics. Also, we believe that the findings presented by proton magnetic resonance spectroscopy may contribute to making a differential diagnosis.

Pulmonary miliary papillary/micropapillary adenocarcinoma manifesting as carcinomatous encephalitis

“…Apart from meningeal carcinomatosis, the brain metastases also showed an unusual spread confined to the Virchow–Robin spaces, referred to as carcinomatous encephalitis. This spread is seldom associated with intra-parenchymal invasion, undetected in plain skull films and computed tomography, but better demonstrated by magnetic resonance imaging,[ 8 ] as noted in our case as well. The condition poses a clinical challenge as symptoms are diverse.…”

“…Some patients are asymptomatic, whereas others have symptoms that mimic psychiatric, metabolic, or infective disorders. [ 8 ] Our patient had a clinical diagnosis of conversion reaction. On literature review, about 24 cases have been reported, with the majority of the metastases originating from papillary/micropapillary pulmonary adenocarcinomas.…”

“…On literature review, about 24 cases have been reported, with the majority of the metastases originating from papillary/micropapillary pulmonary adenocarcinomas. [ 8 9 ] Although the prognosis remains dismal, targeted therapy along with radiation can be effective treatment options. [ 8 9 ] The right adrenal in this patient showed "tumor-to-tumor" metastasis.…”

“…[ 8 9 ] Although the prognosis remains dismal, targeted therapy along with radiation can be effective treatment options. [ 8 9 ] The right adrenal in this patient showed "tumor-to-tumor" metastasis. [ 10 ] Metastasis of existing carcinoma to adrenal adenoma is well-known for nonfunctional adenomas but rare in functional adenomas.…”

Clinical features of lung adenocarcinomas with epidermal growth factor receptor mutations and miliary disseminated carcinomatosis

“…8,11,12 We have occasionally encountered advanced lung cancer patients with multiple miliary metastatic lesions on distant organs. [13][14][15] We collectively refer to miliary intrapulmonary and distant site metastases as "milary dissemination carcinomatosis" and describe its clinical phenotype in lung adenocarcinomas with EGFR mutations in this study. We also compare the response of miliary and non-miliary disseminated carcinomatosis to EGFR-TKIs.…”