Unusual pontine metastasis of endometrial papillary serous carcinoma: illustrative case.

Background: Endometrial papillary serous carcinoma (EPSC) is a rare gynecological malignancy that often metastasizes before the presentation of symptoms or diagnosis of the primary disease. The most common locations of metastases for this malignancy are the lungs, liver, and bones. Metastases to the central nervous system (CNS) are rare. Solitary CNS metastases without other anatomical site spread are exceedingly rare.

Observations: A 65-year-old female with a past medical history of EPSC presented with right-sided weakness, gait instability, and progressive dysarthria. Neurological evaluation revealed right hemiparesis and dysarthria. Head computed tomography showed an ovoid area of hypoattenuation in the left pons. Magnetic resonance imaging confirmed a 2.6-cm pontine lesion. A biopsy revealed histomorphology and immunophenotype consistent with metastasis of previously diagnosed serous carcinoma of the endometrium.

Lessons: Gynecological malignancies, in particular EPSC, can metastasize to atypical locations even without evidence of systemic disease. The authors hypothesize that this may be due to hematogenous spread through the Batson venous plexus. https://thejns.org/doi/10.3171/CASE24513.