Malignant Tissue Missed During Mohs Micro-Surgery

This case involves a female patient who presented to a dermatology facility because of two suspicious spots that appeared on her face. One of the lesions was determined to be cancerous, and the dermatologist performed a Mohs microsurgery on one of the dark spots. The other spot was not considered to be problematic, according to the initial slides sampled, and no surgery was performed at that site. One year after the procedure, the patient presented to the dermatologist for a follow-up visit. At this time, additional slides were taken of the remaining spot, which resulted in a diagnosis of cancer. Upon further evaluation, it proved to be a very aggressive and invasive mass. The patient had to have her eye removed and subsequently died shortly thereafter from metastatic disease.

Question(s) For Expert Witness

1. Was the Mohs micrographic surgery the only procedure indicated in this patient or would she have benefited from additional procedures?

Expert Witness Response E-005963

MMS is indicated for the treatment of skin tumors that primarily spread by direct extension, that is, tumors that grow contiguously. MMS fails in tumors that have satellitosis, a multicentric origin, or skip areas. Routine surgical excision also fails, however, often at the expense of excessive tissue sacrifice. Therefore, although MMS is most successful in treating certain cutaneous neoplasms, it also can be used alone or in a multidisciplinary approach to achieve the highest possible cure rate for a variety of difficult-to-treat tumors.