Internal Pathology Review of Invasive Melanoma: An Academic Institution Experience

Prior studies of internal pathology review (IPR) for melanoma have shown that changes in the pathology analysis are common. How these changes impact clinical management of melanoma or how the margin status reports may modify has not been evaluated. Our goal was to determine what changes to staging and surgical management occurred after IPR of newly diagnosed melanomas and to determine how the final surgical pathology report may correlate with the IPR.

A retrospective study was conducted from 2014 to 2016 of newly diagnosed invasive melanomas referred to a single National Comprehensive Cancer Network tertiary care center.

A total of 370 cases met inclusion criteria. The most common feature changed after internal review was mitotic rate, in 155 (41.7%) patients, followed by Breslow depth in 99 (26.9%) patients. Tumor staging was changed in 45 (12.2%) patients. The most common change was a T1a lesion being upgraded to a T1b lesion. These tumor staging changes lead to 38 (10.3%) overall staging differences. A biopsy's deep margin status was changed in 27 (7.3%) patients. Outside hospital reports lacked information about deep margin status in 71 (19.2%) of specimens. Based on the National Comprehensive Cancer Network guidelines, 22 (5.9%) patients had changes in their sentinel lymph node biopsy recommendations and one of these patients had a positive node found on pathology. Of those patients who had changes in the T-stage, 16 (4.3%) of them also had changes in the recommended wide local excision radial margin.

IPR of invasive melanoma leads to both changes in staging and the surgical management of melanoma and should remain an important component of care of melanoma patients at a tertiary referral center.