General Dermatology

Accurate Diagnosis Possible in Skin Biopsy After 5 Days Without Formalin Preservation: An Observational Study


Occasionally skin biopsy tissue may be not be immediately placed into a preservative. Cleveland Clinic dermatopathologists assessed how well diagnostic properties of diseased skin tissue are retained on pathology when left out of formalin.

Discarded tissue of known basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) was placed in a closed, empty specimen cup. Each tumor was sampled daily for 5 days, placed in formalin, and then processed for diagnostic pathology evaluation. Slides were reviewed in random order by two board-certified dermatopathologists.

Both physicians were in 100% agreement in their diagnoses. Both were confident in their ability to make a diagnosis, regardless of the amount of time tissue was withheld from formalin.

A diagnosis of BCC and SCC can be made on unpreserved tissue for at least 5 days after biopsy. Thus, it is worthwhile to send unpreserved tissue specimens for histologic processing.

Figures 1A and 1B

Easily identified features of basal cell carcinoma are noted at both day 1 (Figure 1A) and day 5 (Figure 1B) without preservation in formalin. (Hematoxylin-eosin stain)

Figure 1A
Figure 1B