Primary cranial vault germinoma in a 23-year-old man: illustrative case.

backgroundGerminoma is the most common type of germ cell tumor that develops intracranially. Germinomas usually grow in the midline structures, such as the pineal and suprasellar regions, and are rarely found in other locations. To the best of the authors' knowledge, no previous research has reported on growth of this tumor in the cranial vault. OBSERVATIONS: The authors reported an unusual case of primary cranial vault germinoma in a young adult. Macroscopically, the tumor had a solid-soft consistency and grayish color with brownish spots on the surface. The histological examination revealed anaplastic cells with round, hyperchromatic, pleomorphic nuclei; prominent nucleoli; and abundant, clear cytoplasm, arranged in lobules and sheets that were infiltrated by lymphocytes and separated by fibrous connective tissue. These findings were consistent with the histopathological characteristics of germinoma. LESSONS: Primary cranial vault germinoma is a unique tumor because no previous research has reported any growth in that location. It should be considered one of the differential diagnoses of lesions located over the cranial vault. Histopathological examination is still the primary modality for diagnosing these tumors and excluding other differential diagnoses.