Mohs Surgery for Periocular Basal Cell Carcinoma Without a Mohs Surgeon: The First Series in Hong Kong

Purpose To report the first series of Mohs micrographic surgery (MMS) in Hong Kong, where the roles of a Mohs surgeon were shared and coordinated by a "mobile" surgeon.

Prospective non-comparative interventional case series.

20 consecutive Chinese patients (10 male, age 78.5+10.4 years, range 55-91 years) with primary periocular basal cell carcinoma (pBCC) referred to the university oculoplastic unit between October 2007 and August 2013.

MMS were conducted according to a streamlined standard operating procedure emphasizing surgeon-driven mapping, specimen orientation, and on-site clinico-histological correlation with the dermatopathologist at the frozen-section laboratory.

Clinical and histological characteristics of tumors, layers of Mohs procedures, complications, and biopsy-confirmed recurrence at the same location. Results All 20 patients received MMS as planned. Sixteen pBCCs (80%) were diffusely pigmented, and three (15%) were focally pigmented. Sixteen were also nodular. The average tumor diameter was 7+3 (3-15) mm. Seven (35%) were within 2 mm of the punctum. Histologically, 11 (55%) were nodules, and four (20%) were superficial. An average of 1.8+0.8 Mohs levels were performed. Apart from the initial two patients, who required four and three levels, respectively, seven (35%) patients were cleared after the first level of MMS using a 1mm clinical margin. The remaining 11 patients required two levels with an additional 1-2mm margin, but only focally as guided histologically. Defects in 16 patients (80%) were reconstructed by local flaps, two by direct closure, and two with pentagon closure. Among the seven patients with pericanalicular BCC, three patients had their remaining canaliculi successfully intubated, while two developed stenotic upper and two lower punctae postoperatively. One patient had prolonged wound healing. Three patients had lid margin notching, two had medial ectropion, one had medial canthal rounding, and two had lateral canthal dystopia. No recurrence was detected at a mean follow-up of 80+23 months (43 to 113 months) in all patients. Conclusions MMS was successfully introduced in Hong Kong without a Mohs surgeon. Providing complete microscopic margin control and preserving tissues, it was proven to be a valuable treatment option for pBCC. Our multidisciplinary protocol demonstrated that these merits are possible and warrant validation in other resource-limited healthcare settings.