Plurihormonal gonadotroph cell pituitary adenoma: report of a unique case.
OBJECTIVE
Pituitary adenomas producing primarily FSH and to a lesser extent GH, LH, alpha-subunit, TSH and PRL without clinical or laboratory evidence of increased hormone release have not previously been reported. Our aim was to obtain some insight into the possible cytogenesis of this unusual tumor.


METHODS
A 65-year-old woman presented with headaches. Magnetic resonance imaging (MRI) demonstrated a sellar mass. Pituitary hormone assays showed normal blood levels. The tumor was removed by the transsphenoidal approach.


RESULTS
By light microscopy, the adenoma was chromophobic, weakly PAS-positive, and immunoreactive mainly for FSH (85%) and to a lesser extent for GH (30%), LH (15%), alpha-subunit (3%), TSH (2%), and PRL (1%). Although double immunostaining showed hormone reactivities to be localized largely in separate distinct cells, the tumor was ultrastructurally monomorphous, i.e., consisted of a single-cell type, resembling gonadotrophs.


CONCLUSIONS
The cytogenesis of plurihormonal pituitary adenomas is not fully understood. Further investigations are required to clarify the basis for their plurihormonality despite an ultrastructural gonadotroph phenotype.
Al-Shraim
M
M
Department of Laboratory Medicine, St. Michael's Hospital, Ontario, Canada.
Al-Sharim
M
M
Scheithauer
B W
BW
Horvath
E
E
Kovacs
K
K
Smyth
H
H
Coire
C
C
Lloyd
R V
RV
Jastania
R
R
Al-Gahtany
M
M
D000236:Adenoma / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D000368:Aged; D005260:Female; D005640:Follicle Stimulating Hormone / Q000096:biosynthesis; D052681:Gonadotrophs / Q000378:metabolism* / Q000473:pathology*; D013006:Growth Hormone / Q000096:biosynthesis; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D011388:Prolactin / Q000096:biosynthesis; D013972:Thyrotropin / Q000096:biosynthesis
D011388:Prolactin; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D013006:Growth Hormone