Use of mohs surgery in non-keratinocytic tumours

Mohs micrographic surgery (MMS) is recognized as the gold standard for treating many basal cell carcinomas and squamous cell carcinomas, but it is not as well known for non-keratinocytic tumours. MMS utilizes horizontal plane sections and frozen processing, which provides rapid results and a thorough 360-degree assessment, ensuring the complete removal of the cancerous tissue. Slow Mohs procedure allows paraffin edge assessment and IHC use and is indicated for large, deep tumors with invasive structures that are difficult to recognize on frozen sections.

Non-keratinocytic tumors, a diverse group including melanocytic, adnexal, hemato-lymphoid, and soft tissue tumors, are increasingly being considered for MMS. Among these, melanocytic tumors, particularly lentigo maligna melanoma (LMM) and melanoma in situ (MIS), are receiving significant attention. MMS is now also considered for more advanced melanomas, such as pT1a melanomas on the hand and upper extremities with amelanotic components, or melanomas in difficult anatomical locations like acral lentiginous melanomas where standard surgical margins are challenging to achieve. However, the use of MMS for deeper melanomas remains controversial and necessitates further research to establish clear inclusion criteria, refine surgical techniques, and evaluate the benefits for patients.