Persistence and Contemporary Clinical Applications of Mohs Paste: A Scoping Review.

Mohs paste (MP), a zinc chloride-based tissue fixative developed by Frederic E. Mohs, was historically central to skin cancer treatment but declined worldwide following the adoption of the fresh-tissue technique and Mohs micrographic surgery (MMS). Japan remains a notable exception; MMS is not as widely adopted there, while MP persists as a symptom-directed practice across multiple disciplines. We systematically characterized the indications, applications, and limitations of MP to contextualize its contemporary clinical relevance. Following PRISMA-ScR guidelines, PubMed and Scopus were searched through March 2025 for peer-reviewed reports describing the clinical use of Mohs paste, ointment, or chemosurgery as therapeutic interventions for surface or ulcerative lesions. Reports using MP solely as an adjunct within MMS or those without original cases were excluded, and data were synthesized thematically. Fifty-two studies (1964-2024) described 88 patients (36 case reports; 16 case series), predominantly from Japan (48 reports). Patients were mostly female (80.7%) with a median age of 68 years, and most presented with locally advanced or stage III-IV disease. Indications included breast, gynecologic, head and neck, and skin cancers, alongside metastatic cutaneous tumors, sarcomas, and oral cancers, with isolated reports of chronic ulcers and schwannoma. At least one local outcome was reported in 87 patients (98.9%), based on descriptive and non-standardized reporting. Frequently reported local outcomes included bleeding control (78.4%), reduction of exudate (62.5%), reduction of malodor (47.7%), and reduction of tumor volume (44.3%). The most commonly reported adverse event was pain, which required analgesics in some cases. MP was occasionally used concurrently with systemic drug therapy or radiotherapy to stabilize local symptoms. Overall, MP has evolved into a pragmatic, symptom-directed intervention bridging oncology and palliative care. These findings highlight the need for standardized protocols, registry-based evaluation, and clearer positioning of MP within contemporary clinical practice.