gms | German Medical Science

Objective: A subtype of functional lesions called “silent adenomas” has been identified in the 1970s. This entity consists classically in adenomas showing hormone production at the histopatological examination however without clinical signs and symptoms. We report our experience about clinically silent pituitary adenomas with invasion of the cavernous sinus describing the neurosurgical treatment strategy and follow up.

Methods: Within a series of 142 pituitary adenomas operated consecutively with the aid of intraoperative magnetic resonance imaging (MRI) (Brainsuite 1.5T), three patients were identified that were suffering from invasive but clinically silent somatotrophinomas. Tumor size, invasion pattern and hormonal features were studied preoperatively and at long-term follow-up.

Results: In two of the three cases total tumor removal was possible based on intraoperative MRI, the patients show normal hormonal status and no recurrence at three years follow-up. In the third case due to the different features of the tumor, complete resection was not possible due to invasion of the cavernous sinus and a multimodal treatment, including radiosurgery, was performed that allowed regularization of the hormonal status and control of the residual tumor.

Conclusion: Silent somatothropinomas are uncommon. Every case should be evaluated singularly taking into consideration patient´s symptoms, MRI and immunohistochemical features. Total microsurgical excision can be curative, in case of partial removal a tailored adjuvant treatment should be considered. In objectively not resectable tumors preoperative medical treatment with somatostatine analogue remains always an option.