Ectopic Prolactin Secretion From a Uterine Leiomyoma

Area of Science:

• Endocrinology
• Oncology

Background:

• Ectopic hormone production is a known phenomenon, but ectopic prolactin production is infrequently reported.
• Hyperprolactinemia can lead to symptoms such as galactorrhea and hypogonadism.

Observation:

• A 47-year-old woman presented with severe hyperprolactinemia (213-224 ng/mL), galactorrhea, and hypogonadism.
• Standard treatment with cabergoline (1.0 mg twice weekly) was ineffective in lowering prolactin levels.
• A large uterine leiomyoma was surgically excised.

Findings:

• Immunostaining of the excised leiomyoma tissue confirmed the presence of prolactin.
• This finding provides the first direct evidence linking uterine leiomyoma to hyperprolactinemia.
• Excision of the leiomyoma successfully corrected the patient's hyperprolactinemia and hypogonadism.

Implications:

• This case underscores the importance of considering ectopic prolactin sources in patients with unexplained hyperprolactinemia.
• It highlights the diagnostic challenge posed by hyperprolactinemia resistant to standard medical treatment.
• The findings suggest that uterine leiomyomas should be evaluated as a potential cause of ectopic prolactin production.