Primary intracranial immature teratoma in an adult woman: case report and literature review.

Background: Primary immature teratoma of the parietal lobe is an exceptionally rare intracranial germ cell tumor, accounting for < 1% of all primary intracranial malignancies. Due to its rarity and overlapping radiological features with other tumors, such as glioma, immature teratomas are often misdiagnosed. Here, we report the case of a 48-year-old woman with a parietal lobe immature teratoma, initially misdiagnosed as a "glioma," highlighting the diagnostic challenges and management strategies.

Case presentation: A 48-year-old woman presented with progressive headaches. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a space-occupying lesion in the right parietal lobe with inhomogeneous density, distinct margins, and perilesional edema. Initial radiological interpretation suggested a glioma; however, postoperative histopathological examination confirmed the diagnosis of an immature teratoma. Following the first surgery, the patient underwent radiotherapy. Eight months later, MRI detected tumor recurrence, prompting a second surgical resection. The patient had an uneventful recovery and was discharged.

Conclusions: This case underscores the diagnostic and therapeutic challenges of intracranial immature teratomas in adults. Key radiological features include: CT: Inhomogeneous density with fatty components and /or calcifications. MRI: Mixed signal intensity, perilesional edema, and contrast-enhanced annular enhancement with an enhancing mural nodule. Early and accurate diagnosis is critical for optimizing treatment outcomes. Surgical resection remains the cornerstone of management, with adjuvant therapies reserved for recurrent or residual disease. Clinicians should consider immature teratoma in the differential diagnosis of atypical brain parenchymal masses, particularly when imaging findings include inhomogeneous density on CT and mixed signals with annular enhancement on MRI.