gms | German Medical Science

Objective: We present a patient with an individual pathological constellation of McCune-Albright-syndrome as a mosaic display with genetic exclusion of GNAS1-gene. The typical trias of this syndrome is polyostotic fibrous dysplasia, café-au-lait spots and endocrine abnormalities such as precocious puberty, thyroid function disorders and excessive secretion of pituitary growth hormone leading to acromegaly. In our patient with suspected McCune-Albright-syndrome acromegaly caused by a growth hormone producing tumor of the pituitary gland has been proved by endocrinological testing. Because of suspected technical difficulties due to the massively hypertrophic skull base no surgical treatment has been advised so far.

Method: We carefully planned a transsphenoidal resection of the tumor. In the CT-scan we measured a skull base depth of 30 mm excluding the sphenoidal sinus. With MRI we clearly detected a right-sided adenoma. The distance between the two carotid arteries at sella level measured 17 mm. The surgical procedure was supported by neuronavigation and x-ray.

Results: The major technical challenge and most time-consuming was cutting the access through the 30 mm skull base without damaging the carotid arteries. Afterwards the procedure went on in a typical way with easy curettage of soft adenoma and lowering of the diaphragm. The postoperative course had no complications. No diabetes insipidus has been developed by the patient. The postoperative glucose tolerance test showed a normalization of the acromegaly. The patient had no new neurological deficits. The histological result showed a typical adenoma without malignancy. The typical genetic alterations, that had not been confirmed by blood samples, could be confirmed from analysis of the pathological bone.

Conclusions: We have reported of a rare pathological constellation where fibrous dysplasia of the skull base is challenging the surgical treatment of acromegaly. We demontrated that the transsphenoidal access is still a save and profitable technique in pituitary surgery even or especially in cases of abnormal anatomy.