Unusual association of Kallmann syndrome with empty sella and arachnoid cyst

We report the MR findings of a patient with clinical and laboratory evidence of Kallmann Syndrome (KS), a genetic disorder of gonadal and olfactory development, in which unexpected associated anomalies were found. The patient was clinically suffering from hypogonadotropic hypogonadism and left-side hyposmia. MR examination included thin coronal sections of the frontal region to determine presence or absence of olfactory bulb-tract and to evaluate the olfactory sulci. On the left side, the posterior portion of the olfactory sulcus appeared hypoplastic, the bulb was unidentifiable and a dysplastic tangle was seen. Besides these abnormalities of the olfactory system, the presence of empty sella and an arachnoid cyst in the left middle fossa was disclosed. Although not a constant finding, other anomalies have sometimes been reported with KS. The association with empty sella and arachnoid temporal cyst found in the present case, was previously described only once in literature, but in our instance hypogonadism had appeared in an adult patient. Its probable mechanism is discussed.