Is it Necessary to Send Clinically Diagnosed Benign Skin and Subcutaneous Lesions Excised Under Local Anesthesia for Routine Histopathological Examination?

Background The common benign surgical lesions of skin and subcutaneous tissues like lipoma and sebaceous cysts are diagnosed clinically and treated by surgical excision under local anesthesia. The occurrence of malignancy in these lesions is extremely low, and routine histopathological examination (HPE) adds to increased costs and workload on pathologists. This study was undertaken to estimate the clinical concordance and the frequency of malignancy in these lesions. Methods A total of 1,815 HPE reports of clinically benign skin and subcutaneous lesions excised under local anesthesia from January 2014 to December 2018 were studied. Results Lipoma (31.3%) and sebaceous cyst (29.9%) were the common clinical diagnosis in our study. The clinical accuracy in the diagnosis of lipoma was 88.6%, and for sebaceous cyst, it was 72.7%. There were six reports of malignancy in our study from the clinically diagnosed benign skin and subcutaneous lesions (0.33%). None of the cases of lipoma and the sebaceous cyst had a malignancy in the final histopathology report. The frequency of malignancy in the rest of the lesions is 0.85% (six out of 699 cases); (p-value: 0.003). Discussion In the absence of red flag signs, lesions like lipoma, sebaceous cyst, corn, and callus can be discarded without an HPE. We advocate routine HPE of other solid lesions, cystic lesions with solid areas, and pigmented or ulcerated lesions, as the clinical concordance is low and there is a significant occurrence of malignancy in these lesions.