Touch Preparation Analysis of Skin Lesions Is a Rapid, Accurate Diagnostic Technique: A Prospective Clinical-Pathologic Study
RS Ohgami, B Sun, J Kosek, J Tang, S Chen, U Sundram, EJ Schwartz. Stanford University, Stanford, CA
Background: The cytologic analysis of skin based lesions has been largely confined to microbial analysis such as KOH preparation, or Tzanck smears. Skin based cytology methods for the diagnosis of epidermal/dermal lesions are under-developed.
Design: We sought to evaluate the use of touch preparations of skin biopsies as a method for accurately diagnosing lesions. Touch preparations were performed on 56 skin biopsies which included squamous cell carcinomas, basal cell carcinomas, nevi, drug eruptions, and ulcers (among others). Specimens were processed using Diff-Quik solutions. Three independent pathologists, blinded to the final pathologic diagnosis, reviewed slides and were instructed to render a diagnosis using the following categories: 1) Negative for malignancy 2) Reactive 3) Atypical 4) Suspicious for malignancy 5) Diagnostic of malignancy. In addition, pathologists commented on the cellularity of lesions and the general morphologic findings in a separate paragraph. The gold standard for the diagnosis of lesions was considered to be the findings on permanent histology.
Results: The overall specificity for the diagnosis of squamous cell and basal cell carcinomas was 97%; the sensitivity of these diagnoses was 100%. Lesions categorized as reactive corresponded to ulcers without carcinoma, recent biopsy sites, and irritated seborrheic keratoses. In addition, one lesion identified as atypical/suspicious for carcinoma by cytology was histologically bland on initial sections, but after deeper sectioning was shown to be atypical, thus demonstrating the utility of this touch preparation technique. Finally, basal cell carcinomas have a clearly distinct cytomorphology which allows for the confident diagnosis of these lesions; in this study, this technique was 100% sensitive and 100% specific for the diagnosis of basal cell carcinomas.
Conclusions: Touch preparation cytology of skin biopsies is a rapid, accurate, cost-effective methodology for initial screening diagnosis of patients with skin disorders. Such studies allow for the appropriate triage of specimens which may require additional studies. Finally, we describe the cytomorphology of basal cell carcinomas in depth, allowing for the accurate and consistent diagnosis of these lesions. Expansion of this series of cases will help further demonstrate the novel utility of this technique.
Monday, March 22, 2010 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 72, Monday Morning