J Neurol Surg B Skull Base 2018; 79(S 01): S1-S188
DOI: 10.1055/s-0038-1633554
Oral Presentations
Georg Thieme Verlag KG Stuttgart · New York

A Proposed Grading System for Tumor Consistency of Pituitary Adenomas

Ki-Eun Chang
1   University of Southern California, Los Angeles, California, United States
,
Kyohei Itamura
1   University of Southern California, Los Angeles, California, United States
,
Joshua Lucas
1   University of Southern California, Los Angeles, California, United States
,
Gabriel Zada
1   University of Southern California, Los Angeles, California, United States
› Author Affiliations
Further Information

Publication History

Publication Date:
02 February 2018 (online)

 

Background Tumor consistency plays a critical role in the surgeon's ability to resect pituitary adenomas, especially through an endoscopic endonasal approach. The present study aims to clinically validate a proposed intraoperative consistency grading system to objectively assess how consistency affects surgical outcome.

Methods A 5-point scale was designed for intraoperative grading of pituitary tumors based on the surgeon's ability to resect the tumor, ranging from 1 (cystic or hemorrhagic tumor) to 5 (firm or calcified tumor that is not curettable). The proposed grading system was prospectively assessed in 171 consecutive patients undergoing an endoscopic transsphenoidal approach by a single neurosurgeon at our hospital. Grading scores were subjected to chi-square analysis for independence with extent of resection and intraoperative CSF leak.

Results A total of 171 patients were included in the analysis. The distribution of overall tumor consistency scores was as follows: Grade I, 4.1%; Grade II, 28.7%; Grade III, 47.4%, Grade IV, 19.3%, Grade V, 0.6%. For statistical analysis, individual grades were grouped into soft tumors (Grades I–II), average consistency (Grade III), and firm tumors (Grades IV–V). The proportion of subtotal resection (STR) for each category was Grades I to II, 10.7%; Grade III, 23.5%; Grades IV to V, 44.1%. This difference in extent of resection was significant, χ 2 (5, N = 171) = 13.2, p < 0.05. The proportion of intraoperative CSF leak repair for each category was as follows: Grades I to II, 28%; Grade III, 32%; Grades IV to V, 39%. Although not statistically significant, there was a trend toward a higher incidence of intraoperative CSF leaks associated with resection of firmer tumors.

Conclusion Our findings demonstrate clinical validity of the proposed intraoperative grading scale with respect to extent of tumor resection. Future studies will relate intraoperative consistency scores to preoperative MRI studies to predict tumor consistency, better equipping the surgeon for potential modification of approaches and goals of resection.