Sellar/Suprasellar Germinoma Masquerading As Pituitary Adenoma

ABSTRACT

We report a case of sellar/suprasellar germinoma in a 17-year-old female which was misdiagnosed as pituitary adenoma both clinically and on imaging. Patient presented with severe headache of short duration and diminished visual acuity in left eye. Endocrinological work up revealed hyperprolactinemia and markedly reduced blood cortisol. MRI revealed homogenously enhanced intrasellar mass with suprasellar extension showing characteristic dumbbell conguration (snowman sign). Provisional diagnosis of pituitary adenoma was made and transsphenoidal resection of tumor was performed which on histology and immunohistochemistry proved to be germinoma. Sellar/suprasellar germinoma without diabetes insipidus is considered to be very difcult to diagnose preoperatively and the differentiation from pituitary adenoma based on MRI ndings was not possible in this case. However it is suggested that in a child with visual impairment, endocrine dysfunction and sellar/suprasellar mass a possibility of germ cell tumor should always be considered in differential diagnosis and a frozen section has to be performed to avoid excessive dissection.