MOFFITT ENDOCRINE REPORT PEARLS 10/12/16: Incidental Pituitary Masses!

Hi Everyone! Thanks to Harry for presenting the case of an elderly woman with depression found to have two incidentalomas: a small pituitary mass and a larger anterior mediastinal mass! We talked about the differential for each mass, as well as some interesting translational research connections to this case, but we’ll focus here on the pituitary mass. Thanks so much to Mark Anderson for being our expert endocrine and thymoma discussant!


Top pearls:

  • For incidental pituitary macroadenomas (>1 cm), send labs for the anterior pituitary hormone pathways: Prolactin, IGF-1, ACTH, 24-hour urine free cortisol (+/- TSH/FT4/FT3 and FSH/LH)
  • For incidental pituitary microadenomas (<1 cm), only prolactin is necessary.
  • No matter the size or extent of neurologic deficits, initial therapy for prolactinomas is a dopamine agonist! Surgery is reserved for cases refractory to medical therapy.


For those who want more info:

Pituitary/sellar masses:

Present as neuro sx (visual or headache), hormonal abnormalities, or incidental finding.

Ddx of sellar mass is not very long, see table below. In general, think benign or malignant tumors (primary and metastatic), hyperplasia, and cysts. Of metastatic tumors, lung (men) and breast (women) are most common cancers to metastasize to the pituitary.

Pic 1.jpg

Pituitary adenoma is the most common cause in adults. To remember the different adenomas, remember the anterior pituitary hormones!

  • Prolactin/Lactotroph adenomas: Usually cause hyperprolactinemia and hypogonadism!
  • Growth hormone/Somatotroph adenomas: Usually cause acromegaly!
  • ACTH/Corticotroph adenomas: Usually cause Cushing disease!
  • TSH/Thyrotroph adenomas: May cause hyperthyroidism or may be clinically non-functioning.
  • FSH and LH/Gonadotroph adenomas: Usually clinically non-functioning.

Prolactinomas are the most common, followed by clinically “non-functioning” adenomas that don’t cause endocrine manifestations, then GH adenomas and ACTH adenomas.

MRI is the first step in workup.

Lab workup of the anterior pituitary hormone pathways is recommended whenever a macroadenoma (>1 cm) is encountered. If < 1 cm (microadenoma) and no clinical findings, only prolactin needs to be measured.

Workup: Prolactin, IGF-1, ACTH and 24-hour urinary free cortisol (or pm salivary cortisol). TSH/FT4/FT3 and FSH/LH may also be sent (challenging to interpret FSH/LH in post-menopausal patients).

Treatment: Usually surgical resection, keeping in mind that macro and microprolactinomas can be treated medically with dopamine agonists. In fact, no matter how large or severe the neurologic deficits, initial recommended treatment is still a dopamine agonist! Surgery is only recommended if refractory to medical therapy or in women with large prolactinomas who wish to become pregnant.


Lastly, remember the 4 T’s for anterior mediastinal masses!

  • Thymoma
  • Thyroid tumor
  • Teratoma
  • Terrible lymphoma



Have a great day everyone!



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