BACKGROUND: Pituitary adenomas are usually well-differentiated tumors but may show locally aggressive behavior. AIM: To investigate the relationship between proliferation and apoptosis parameters and tumor recurrence in a series of 20 radically resected pituitary macroadenomas (11 functioning, 9 non-functioning). MATERIALS AND METHODS: Proliferative activity and DNA ploidy were analyzed by flow cytometry (FCM) on fresh surgical specimens. Immunohistochemistry for Ki-67/MIB-1 and for the anti-apoptotic protein Bcl-2 was performed on paraffin-embedded specimens from the same tumors. Tumor regrowth was evaluated by magnetic resonance imaging (MRI). RESULTS: Six adenomas recurred after surgery, regardless of hormonal hypersecretion. Pre-surgical tumor size was significantly higher in recurrent than in non-recurrent adenomas (p=0.003). Pre-surgical MRI demonstrated cavernous sinus (CS) invasiveness in all recurrent tumors, while none of the non-invasive adenomas recurred (p=0.042, by Fisher's exact test). The DNA content was aneuploid in 5/20 adenomas, one of which recurred. Cell percentages in the S (%SPF) and G2+M (%G2-M) phases and proliferative index (PI) (PI= %SPF + %G2-M) were significantly higher in aneuploid than in diploid adenomas (p<0.05), but no significant differences concerning all FCM parameters were observed between recurrent and non-recurrent adenomas. Similarly, MIB-1 did not show a significant difference of expression between recurrent and non-recurrent adenomas (p=0.33). Bcl-2 immunoreactivity was detected in 12/15 pituitary adenomas, involving 63±35% of tumor cells, regardless of tumor recurrence. CONCLUSIONS: In this group of radically resected pituitary macroadenomas, neuroradiological finding of CS invasiveness - but not FCM parameters nor MIB-1 and Bcl-2 expression - is useful for predicting tumor recurrence.

Cell proliferation parameters and apoptosis indices in pituitary macroadenomas

RUGGERI, Rosaria Maddalena;COSTA, Gregorio;SIMONE, Angela;CAMPENNI', Alfredo;SINDONI, ALESSANDRO;IENI, ANTONIO;CAVALLARI, Vittorio;TRIMARCHI, Francesco;
2011

Abstract

BACKGROUND: Pituitary adenomas are usually well-differentiated tumors but may show locally aggressive behavior. AIM: To investigate the relationship between proliferation and apoptosis parameters and tumor recurrence in a series of 20 radically resected pituitary macroadenomas (11 functioning, 9 non-functioning). MATERIALS AND METHODS: Proliferative activity and DNA ploidy were analyzed by flow cytometry (FCM) on fresh surgical specimens. Immunohistochemistry for Ki-67/MIB-1 and for the anti-apoptotic protein Bcl-2 was performed on paraffin-embedded specimens from the same tumors. Tumor regrowth was evaluated by magnetic resonance imaging (MRI). RESULTS: Six adenomas recurred after surgery, regardless of hormonal hypersecretion. Pre-surgical tumor size was significantly higher in recurrent than in non-recurrent adenomas (p=0.003). Pre-surgical MRI demonstrated cavernous sinus (CS) invasiveness in all recurrent tumors, while none of the non-invasive adenomas recurred (p=0.042, by Fisher's exact test). The DNA content was aneuploid in 5/20 adenomas, one of which recurred. Cell percentages in the S (%SPF) and G2+M (%G2-M) phases and proliferative index (PI) (PI= %SPF + %G2-M) were significantly higher in aneuploid than in diploid adenomas (p<0.05), but no significant differences concerning all FCM parameters were observed between recurrent and non-recurrent adenomas. Similarly, MIB-1 did not show a significant difference of expression between recurrent and non-recurrent adenomas (p=0.33). Bcl-2 immunoreactivity was detected in 12/15 pituitary adenomas, involving 63±35% of tumor cells, regardless of tumor recurrence. CONCLUSIONS: In this group of radically resected pituitary macroadenomas, neuroradiological finding of CS invasiveness - but not FCM parameters nor MIB-1 and Bcl-2 expression - is useful for predicting tumor recurrence.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11570/1910964
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