Ectopic prolactinoma of the sphenoidal sinus: case report

A 34-year-old woman was hospitalized for exploration of amenorrhea and galactorrhea. She had experienced primary sterility, diagnosed 11 years earlier. Endocrine tests demonstrated hyperprolactinemia (serum prolactin 594 ng/ml). Magnetic resonance imaging (MRI) showed a soft tissue mass located within the posterior part of the sphenoidal sinus. The pituitary gland appeared normal. Medical treatment with bromocriptine was unsuccessful. Transsphenoidal tumor resection was performed. Histology reported adenoma, which was consistent with prolactin-producing tumor demonstrated by immunohistochemical staining for prolactin. Because of the persistence of hyperprolactinemia related to an intra-sphenoidal tumor remnant, bromocriptine (15 mg/d) was initiated. Menses ensued and prolactin level declined (49 ng/ml). One year later, the tumor remnant had disappeared on the MRI and the patient became pregnant. Ectopic adenomas of the sphenoidal sinus are of particular interest due to the diagnostic difficulties encountered. Nevertheless, the nature of the lesion can be determined from the endocrine manifestations. Some of these tumors respond to medical treatment, similar to intra sellar tumors. Surgery remains however the only means of obtaining definitive diagnosis and cure.