Uncommon metastases to the brain: Frontal lobe myoepithelial carcinoma

Abstract

Background: Myoepithelial tumors have been widely described as a rare form of salivary gland neoplasm, although currently soft-tissue phenotypes have also been identified. These are tumors composed entirely of myoepithelial cells that exhibit a dual epithelial and smooth muscle phenotype. The occurrence of myoepithelial tumors within the central nervous system is also extremely rare, with only a few cases reported. Treatment options include surgical resection, chemotherapy, radiotherapy, or a combination of these approaches.

Case description: The authors present a case of soft-tissue myoepithelial carcinoma with an unusual brain metastasis, rarely described in the literature. The purpose of this article is to present an update on the diagnosis and treatment of this pathology when affecting the central nervous system, through the review of the current evidence.

Conclusion: However, despite complete surgical resection, there is about a significative high rate of local recurrence and metastasis. Careful patient follow-up and staging is essential for better characterization and understanding of this tumor's behavior.

Keywords: Brain neoplasms; Intracranial; Myoepithelioma; Neuro-oncology; Pathology.

Figure 1:

(a) T1-weighted axial magnetic resonance imaging (MRI) and (b) contrast-enhanced T1-weighted MRI showing a tumor within the frontal lobe with irregular peripheral enhance causing significant mass effect and midline shift; (c) contrast-enhanced T1-weighted coronal MRI showing tumor extension on the underlying brain parenchyma.

Figure 2:

(a) Computed tomography scan in the immediate postoperative period; (b) and (c) contrast-enhanced T1-weighted and T2 magnetic resonance imaging sequences 2 months following surgery, showing no evidence of residual tumor.

Figure 3:

(a) Myoepithelial carcinoma invading the brain parenchyma. Hematoxylin and eosin (H&E), × 20; (b) cords of malignant cells immersed in myxoid stroma. H&E, ×40 (c) Diffuse, cytoplasmic CKAE1/AE3 positivity immunohistochemistry (IHC), ×40; (d) SOX 10 diffuse, nuclear positivity (IHC), ×40.

Figure 4:

(a and b) T1-weighted axial magnetic resonance imaging with and without contrast showing extensive tumor recurrence 7 months after surgery with significant peripheral edema and compression of the lateral ventricle on T2 sequence (c).