Novel Comprehensive Grading for Giant Pituitary Adenomas: Slap Grading

Introduction: Giant pituitary adenomas are difficult to resect due to multicompartmental extension. We developed a new grading system for giant pituitary adenomas (GPAs) considering possible extension in superior, lateral, anterior, and posterior (SLAP) directions. We also determined the predictability of SLAP grading on the extent of resection.

Methods: A review of case files and radiological images of patients with the GPAs defined as pituitary adenomas with a size of more than 4 cm in any dimension was done. The extent of the tumor was noted, and scored as per the SLAP system. The largest tumor with maximum extensions in all directions has a maximum total score of 10. The subtotal resection (STR) was defined as residual tumor volume of more than 10%. The median score was determined and the association between individual and total score the extent of resection was determined.

Results: A total of 103 cases of the GPAs were analyzed. All patients had a suprasellar (S) extension, and most had a lateral extension. The lateral (L) extension was seen in 97.3% of cases. The anterior (A) extension was seen in 28 (27.2%) cases. The posterior extension (P) was seen in 45 (43.7%). Forty-eight (46.6%) had a total score of 5 or more. The STR was achieved in 64 (62.2%) cases. On regression analysis, a total score of ≥5 was associated with odds of 5.02 (1.69–14.93), and p-value was 0.004 for STR.

Conclusion: The SLAP grading is a useful grading system that can be applied easily to GPAs, and gives a complete picture of the extension of the tumor.

Publication History

Article published online:
15 February 2022