Assessment of retraction in surgical specimens in melanoma patients submitted to oncological amplification of margins.

INTRODUCTION

Skin cancer is the most common type of cancer and represents more than half of the diagnosed malignant tumors. There are more than one million new cases per year in the United States and about 120.000 new cases in Brazil. Cutaneous melanoma represents 5% of all primary cutaneous neoplasms; however, it has a worse prognosis. Adequate treatment of the primary lesion is the main cure factor, with free surgical margins, thus avoiding recurrences of the lesion.

OBJECTIVES

The present study aims to evaluate and quantify the retraction of the surgical specimen in three moments, in-vivo, ex-vivo and in-vitro, and also evaluating possible factors related to retraction, such as formalin fixation, age, patient's gender, and lesion location.

METHODS

This is a prospective, single-center cohort that evaluated 145 surgical specimens from patients who underwent oncological surgery of cutaneous melanoma margins enlargement. Lesions were marked with a standard brush, and surgical margins were measured with a sterile ruler, according to their initial staging. After resection, new surgical specimens measurements were obtained, and, after fixation in formalin, the last measurement was performed. The same oncological surgeon performed all procedures, and the same pathologist analyzed the specimens.

RESULTS

Regarding the area of the specimens, there was a general median retraction of 38.15% between in-vivo and ex-vivo (p < 0.001), and 43.97% between in-vivo and in-vitro. When the measure of the specimen length (L) was evaluated, there was a 17% retraction between in-vivo and ex-vivo, and 20.42% between in-vivo and in-vitro, with statistical significance. The younger population has a higher rate of retraction, and lesions on the back have a lower rate of shrinkage on the opposite of lower limbs that had higher shrinkage.

DISCUSSION

Corroborating the literature, this study showed an average shrinkage of 20.42% for length measurements between in-vivo and in-vitro, and the main predictors of greater or lesser retraction were age and location of the lesion. It is also noted that the most considerable retraction occurs immediately after surgical resection, indicating that skin characteristics, such as degree of elasticity and tension, are determinant for the retraction. Formalin action does not significantly impact retraction. This study shows the importance of adequate treatment of the primary lesion, with adequate surgical margins, and that the measure measured by the pathologist, in general, represents 80% of the margins performed in the perioperative time.