In more than 95% of cases
acromegaly is due to GH hypersecretion by a
pituitary adenoma. GHRH hypersecretion accounts for about 0.5% of cases of
acromegaly. Intracranial GHRH-secreting
tumors are extremely rare and only a few well-documented cases have been reported. The clinical features of
acromegaly due to intracranial GHRH-secreting
tumor are indistinguishable from those of other patients with "classical
acromegaly". In cases of intrasellar
gangliocytomas, not even radiological findings help to make the correct diagnosis, which can only be made with the hystological study. We present the case of a woman with
acromegaly; the magnetic resonance demonstrated a 2x1.8x1.2 cm mass in the jugum sphenoidalis region, associated with a partial empty sella. There was a partial response to high-dose
lanreotide therapy, so surgical treatment was decided, although only part of the
tumor could be removed. Histopathological diagnosis was consistent with
gangliocytoma, and immunostaining in the ganglionic cells was positive for GHRH. After surgery,
hormone hypersecretion persisted, so medical treatment was reintroduced. In summary, we report a well-documented case of an intracranial GHRH-secreting
gangliocytoma, an exceedingly rare cause of
acromegaly. Clinical and biochemical data did not allow to make the correct diagnosis, which was only made on the pathological study. This case underscores that
acromegaly can be due to causes other than a GH-secreting
adenoma, and underlines that finding an image not typical of a
pituitary adenoma should raise the suspicion that an unusual cause subsides the
acromegaly.