Endocrine Abstracts

We describe a case of aggressive pituitary adenoma with atypical biological behavior treated with surgery radiation & chemotherapy. A 46 y/o F presented with nausea & acute vision loss R>L,with no symptoms of amenorrhea, hypothyroidism or hypoadrenalism. Brain MRI showed 4.7×3.6×3.6 cm pituitary macroadenoma with mass effect on optic chiasm, cavernous sinus extension, internal carotid artery encasement, extension into R foramen ovale, orbital apex, sphenoid & ethmoid sinus, prepontine cistern resulting in mass effect on midbrain & pons. Pituitary hormone profile was TSH 1.41 mcU/ml (0.4–5) FT4 0.53 ng/ml (0.8–1.8) ACTH 20pg/ml (6–46) Prolactin 20.6 ng/ml (<0.5–25) FSH 1.4 mU/ml (1–25) LH 0.2 mU/ml (0.1–77) GH 7.9 ng/ml cortisol 2.9 mcg/dl(5–25). She had tumor debulking & optic nerve decompression. Postop MRI showed residual tumor with extension into medial brain structures. Tumor pathology showed sparsely granular chromophobe staining pattern, chromogrannin immunohistochemistry +, CAM 5.2 & cytokeratin + fibrous bodies. Ki67 labelling index 10%. Pathological classification was nonfunctional chromophobe adenoma. Symptoms & vision improved but she had residual R visual loss. Postop pituitary hormone profile revealed TSH 0.088 mcU/ml, FT4 0.54 ng/dl, IGF 532 ng/ml (288–736), ACTH 13 pg.ml (5–27), am cortisol 10.6 ng/ml (4–22). She received DDAVP for transient diabetes insipidus, thyroxine for secondary hypothyroidism & hydrocortisone taper. 1 month CT showed marked increase in residual tumor, near doubling of tumor volume, complete encasement of optic nerve, extension into orbit & cranial base pathways down to hypoglossal canal. She underwent gammaknife therapy, temozolamide chemotherapy & radiological surveillance. While there are no endocrinological, neuroradiological & histological criteria to distinguish pituitary adenoma & carcinoma MIB-1 index of 10%, invasive growth pattern & mitotic activity predicted aggressive biologic behavior of this atypical adenoma(1). As pituitary carcinomas are thought to arise from transformation of benign invasive macroadenomas, given the potential for malignant transformation of this invasive adenoma & due to higher risk of immediate revision surgery, temozolamide & radiation was initiated. We are monitoring response to radiation & chemotherapy with imaging.

1. J Neurosurg. 2011Feb;114(2):336–44.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.