Incomplete Staining Artifact: A Confounding Frozen Section Pathology Artifact Encountered During Mohs Micrographic Surgery
May 2022 | Volume 21 | Issue 5 | Features | 544 | Copyright © May 2022
Published online April 29, 2022
Nicholas Flint BS,a Philicia Friedman BA,b Alice Frigerio MD PhD,b Adam Tinklepaugh MDb
aSchool of Medicine, University of Utah, Salt Lake City, UT
bDepartment of Dermatology, University of Utah, Salt Lake City, UT
Abstract
The intent of this brief communication is to describe a unique incomplete staining frozen section pathology artifact encountered during Mohs Micrographic Surgery. At the authors’ institution, an amorphous, eosinophilic artifact that obscured cellular architecture was observed multiple times during histological interpretation. It was determined that incomplete tissue staining was likely caused by weak staining, possibly related to an interaction between hematoxylin dye solution and acetone. We adjusted our SLS stain line protocol by adding a 15 second water rinse between the acetone and hematoxylin pots and then compared the old fixation protocol with our new fixation protocol. This artifact, which was regularly found intraoperatively at five separate MMS laboratories has sustainably resolved.
Mohs Micrographic Surgery (MMS) is a dermatologic procedure that includes tumor extirpation, tissue grossing, slide preparation, and microscopic histologic interpretation. Tissue grossing and slide preparation are vital components of the MMS procedure. There are many steps throughout tissue processing that can result in frozen section pathology artifacts. Frequently encountered frozen section pathology artifacts include vacuolation of cytoplasm or “freeze artifact,” overstaining and understaining with hematoxylin and eosin, incomplete dehydration, and splaying of collagen in the dermis.1-3 We describe a unique incomplete staining frozen section pathology artifact.
J Drugs Dermatol. 2022;21(5):542-544. doi:10.36849/JDD.6722
INTRODUCTION
On histologic interpretation during MMS, the authors observed numerous areas of incompletely stained tissue where cellular architecture was preserved, but obscured by an amorphous, eosinophilic artifact that eliminated contrast between the hematoxylin and eosin-stained cells. The incompletely stained areas were rounded areas of decreased staining intensity that crossed cellular boundaries (Figure 1A). Because of the importance of cellular variegation in MMS histologic interpretation, the staining artifact proved challenging when discerning between benign and malignant cellular features. The reliability of MMS in preventing skin cancer recurrence relies on the precision of slide preparation and histologic interpretation. Technical and interpretational errors may account for greater than 75% of local skin cancer recurrence after MMS with technical laboratory problems accounting for the largest portion of those errors.4
SOLUTION
After troubleshooting with the ASMH frozen section manual, it was determined that incomplete tissue staining was likely
