A Case Report Emphasizing the Importance of Early Diagnosis and Management of Intracranial Germinoma.

Intracranial germ cell tumors (GCTs) account for 3%-5% of all intracranial tumors. They commonly manifest during first two decades of life. We are reporting a case of a young female, who presented with progressive visual loss, polyuria and polydipsia, harboring an intracranial GCT. She presented initially to a neurosurgery clinic and then to an endocrine clinic, with a history of chronic worsening headache and recent onset visual blurring along with polyuria with polydipsia. On further inquiry, she was found to have primary amenorrhea, easy fatigability, and failure of development of secondary sexual characteristics. On examination the patient had bitemporal hemianopia with breast development at tanner stage II and pubic and axillary hair at tanner stage I. Her initial hormonal workup was suggestive of panhypopituitarism with diabetes insipidus. MRI pituitary showed a sellar mass with suprasellar extension, so an initial impression of a pituitary macroadenoma was made and the patient underwent trans-sphenoidal surgery. The histopathology was suggestive of lymphoid hyperplasia. Follow up MRI showed significant residual tumor and her vision and pituitary function did not recover. Neurosurgery was planned as second surgery, but we requested a second opinion of histopathology report and it was suggestive of a germinoma. She was then started on chemotherapy followed by radiotherapy, after which her tumor size reduced significantly, though she still required pituitary hormone replacement therapy.  Pituitary stalk lesions are rare and their diagnosis is challenging as different etiologies present clinically and radiologically in a similar manner with tissue diagnosis being the gold standard. Germinoma is a radiosensitive tumor. In our patient it took a long time to reach the correct diagnosis and late diagnosis resulted in permanent visual field defect and panhypopituitarism. This case report emphasizes that we should guide and educate our patients to seek medical advice early in the course of disease. We should also keep differential diagnosis in mind before referring the patient for surgery.