Ectopic hyperprolactinaemia in a woman with a mesocolic perivascular epithelioid cell tumor ("PEComa")

Ectopic prolactin secretion remains exceptional and originates mainly from malignant tumors. We report the case of a 47-year-old woman who presented amenorrhea leading to unravel important hyperprolactinaemia (269 ng/mL) with no hypothalamo-pituitary mass on magnetic resonance imaging (MRI). Pelvic imaging revealed the presence of a large pelvic mass that originated from the mesocolon. After complete surgical extraction, histological examination was in favour of a "perivascular epithelioid cell tumor" (PEComa). Prolactin levels normalized after surgical extraction and remained normal after a 3-year follow-up, totally free of tumour recurrence and/or metastasis. This suggests that hyperprolactinaemia was most likely related to the PEComa, despite negative reactions with antiprolactin antibodies at immunohistochemistry. Alternatively to a direct prolactin secretion by the tumor, one could hypothesize that the tumour secreted a prolactin stimulating factor or a dopamine antagonist that could not be identified. In conclusion, in face of an important hyperprolactinaemia without any hypothalamic-pituitary mass, it remains important to search for an ectopic prolactin production, such as a PEComa.