A case report followed by a literature review are presented.
RESULTS: A 68-year-old woman presented for evaluation of resistant
hypertension. Biochemical testing demonstrated
adrenocorticotropic hormone (
ACTH)-dependent hypercortisolemia and
growth hormone (GH) excess. Pituitary magnetic resonance imaging (MRI) revealed a 2 cm left sellar lesion consistent with a pituitary macroadenoma. The patient therefore underwent transsphenoidal surgery for a presumed cosecreting
ACTH and GH macroadenoma.
Tumor immunohistochemical staining (IHC) was positive for
ACTH, but negative for GH. Postoperative biochemical testing confirmed remission from
Cushing disease, but the
insulin-like growth factor 1 (IGF-1) level remained elevated. Postoperative MRI demonstrated a small right sellar lesion that, in retrospect, had been present on the preoperative MRI. Resection of the right lesion confirmed a GH-secreting
adenoma with negative
ACTH staining. After the second surgery, the
IGF-1 level normalized and blood pressure improved. Further pathologic examination of both surgical specimens demonstrated differential expression of
S-100 protein, a folliculostellate cell marker. Reverse transcription polymerase chain reaction of messenger
ribonucleic acid from the left sellar lesion was positive for
ACTH and negative for GH, confirming the IHC results. Germline mutations in genes known to be associated with
pituitary adenoma syndromes (MEN1, CDC73, CDKN1A, CDKN1B, CDKN2B, CDKN2C, and AIP) were not detected.
CONCLUSION: Although the pathogenesis of synchronous
pituitary adenomas has not been fully elucidated, this case report suggests that they can have distinct molecular lineages.