madman
Super Moderator
Abstract
Purpose Men with mild to moderate hyperprolactinemia rarely present with normal pituitary on MRI with no visible adenoma, a condition entitled also “idiopathic hyperprolactinemia” or “non-tumoral hyperprolactinemia”. We have characterized a cohort of hyperprolactinemic men with normal pituitary imaging.
Design We have identified 13 men with true hyperprolactinemia and normal pituitary MRI. Baseline clinical and hormonal characteristics and response to medical treatment were retrospectively retrieved from medical records.
Results Mean age at diagnosis was 51 ± 16 years (range, 20–77); mean serum prolactin level at presentation was 91 ng/ml (range, 28–264), eight men presented with low baseline testosterone. Initial complaints leading to diagnosis included sexual dysfunction in ten men and gynecomastia in five. All patients were treated with cabergoline, except for one who was given bromocriptine; none required pituitary surgery. All patients normalized prolactin and testosterone with subsequent clinical improvement reported by most men. Currently, after a mean follow-up of 72 months, ten patients continue treatment with cabergoline (median weekly dose, 0.25 mg), whereas three men discontinued treatment.
Conclusions Men with symptomatic hyperprolactinemia may rarely present with normal pituitary imaging. Medical treatment can lead to hormonal improvement with clinical benefit.
Introduction
Prolactinomas, benign prolactin (PRL)-secreting tumors, are the most common functional pituitary adenomas, accounting for 60% of secreting pituitary tumors. Prolactinomas are subdivided into microprolactinomas (<10 mm) and macroprolactinomas (≥10 mm) based on their size at presentation [1]. In women, most prolactinomas (90%) are microadenomas [2], whereas males present with macroadenomas in 80–85% of the cases, many of them are very large and invasive [3]. Thus, microadenomas account for only 10–15% of all male prolactinomas [4]. Men with mild to moderate hyperprolactinemia may rarely present with normal pituitary MRI imaging and no visible adenoma, and this condition is also entitled “idiopathic hyperprolactinemia” or “non-tumoral hyperprolactinemia”. Drug-induced hyperprolactinemia, macroprolctinemia, chronic renal failure, and primary hypothyroidism must be excluded, and repeated prolactin measurement 2–3 h after waking up from sleep will establish this rare diagnostic entity of idiopathic hyperprolactinemia. These rare cases will usually imitate very small pituitary microprolactinomas (1–3 mm in diameter) not depicted by the 3-Tesla MRI systems currently in use, similarly to the far more frequent idiopathic hyperprolactinemia commonly encountered in hyperprolactinemic women [5].
Men with idiopathic hyperprolactinemia can present differently from males with micro- or macropaprolactinomas, but usually, respond to medical treatment with dopamine agonists, with suppression of PRL to normal and subsequent clinical improvement.
As idiopathic hyperprolactinemia is uncommon in men, we report our experience with the diagnosis and treatment of 13 male patients with true hyperprolactinemia and no visible pituitary adenoma on MRI.
*Prolactinomas in women and men respond to cabergoline, achieving PRL normalization in 85–95% of microprolactinomas, and 75–85% for macroprolactinomas [4, 13, 14]. In our cohort, all patients responded to cabergoline with PRL suppression to normal. This is in line with the trend of small prolactinomas to respond better to dopamine agonist treatment compared to macroadenomas or giant prolactinomas in men [15]. Moreover, the cabergoline dosage used was relatively low, and patients were continuously maintained and controlled with a median dose of 0.25 mg/week. However, men that discontinued dopamine agonist treatment-experienced a relapse of hyperprolactinemia.
In conclusion, men with symptoms of hypogonadism rarely present with hyperprolactinemia without visible pituitary adenoma. This true hyperprolactinemia, albeit mild responds to treatment with dopamine agonists together with subsequent clinical improvement in most men, thus highlights the benefits patients with such a rare condition may obtain.
Purpose Men with mild to moderate hyperprolactinemia rarely present with normal pituitary on MRI with no visible adenoma, a condition entitled also “idiopathic hyperprolactinemia” or “non-tumoral hyperprolactinemia”. We have characterized a cohort of hyperprolactinemic men with normal pituitary imaging.
Design We have identified 13 men with true hyperprolactinemia and normal pituitary MRI. Baseline clinical and hormonal characteristics and response to medical treatment were retrospectively retrieved from medical records.
Results Mean age at diagnosis was 51 ± 16 years (range, 20–77); mean serum prolactin level at presentation was 91 ng/ml (range, 28–264), eight men presented with low baseline testosterone. Initial complaints leading to diagnosis included sexual dysfunction in ten men and gynecomastia in five. All patients were treated with cabergoline, except for one who was given bromocriptine; none required pituitary surgery. All patients normalized prolactin and testosterone with subsequent clinical improvement reported by most men. Currently, after a mean follow-up of 72 months, ten patients continue treatment with cabergoline (median weekly dose, 0.25 mg), whereas three men discontinued treatment.
Conclusions Men with symptomatic hyperprolactinemia may rarely present with normal pituitary imaging. Medical treatment can lead to hormonal improvement with clinical benefit.
Introduction
Prolactinomas, benign prolactin (PRL)-secreting tumors, are the most common functional pituitary adenomas, accounting for 60% of secreting pituitary tumors. Prolactinomas are subdivided into microprolactinomas (<10 mm) and macroprolactinomas (≥10 mm) based on their size at presentation [1]. In women, most prolactinomas (90%) are microadenomas [2], whereas males present with macroadenomas in 80–85% of the cases, many of them are very large and invasive [3]. Thus, microadenomas account for only 10–15% of all male prolactinomas [4]. Men with mild to moderate hyperprolactinemia may rarely present with normal pituitary MRI imaging and no visible adenoma, and this condition is also entitled “idiopathic hyperprolactinemia” or “non-tumoral hyperprolactinemia”. Drug-induced hyperprolactinemia, macroprolctinemia, chronic renal failure, and primary hypothyroidism must be excluded, and repeated prolactin measurement 2–3 h after waking up from sleep will establish this rare diagnostic entity of idiopathic hyperprolactinemia. These rare cases will usually imitate very small pituitary microprolactinomas (1–3 mm in diameter) not depicted by the 3-Tesla MRI systems currently in use, similarly to the far more frequent idiopathic hyperprolactinemia commonly encountered in hyperprolactinemic women [5].
Men with idiopathic hyperprolactinemia can present differently from males with micro- or macropaprolactinomas, but usually, respond to medical treatment with dopamine agonists, with suppression of PRL to normal and subsequent clinical improvement.
As idiopathic hyperprolactinemia is uncommon in men, we report our experience with the diagnosis and treatment of 13 male patients with true hyperprolactinemia and no visible pituitary adenoma on MRI.
*Prolactinomas in women and men respond to cabergoline, achieving PRL normalization in 85–95% of microprolactinomas, and 75–85% for macroprolactinomas [4, 13, 14]. In our cohort, all patients responded to cabergoline with PRL suppression to normal. This is in line with the trend of small prolactinomas to respond better to dopamine agonist treatment compared to macroadenomas or giant prolactinomas in men [15]. Moreover, the cabergoline dosage used was relatively low, and patients were continuously maintained and controlled with a median dose of 0.25 mg/week. However, men that discontinued dopamine agonist treatment-experienced a relapse of hyperprolactinemia.
In conclusion, men with symptoms of hypogonadism rarely present with hyperprolactinemia without visible pituitary adenoma. This true hyperprolactinemia, albeit mild responds to treatment with dopamine agonists together with subsequent clinical improvement in most men, thus highlights the benefits patients with such a rare condition may obtain.
