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. METHODS DESIGN: Prospective non-comparative interventional case series. SUBJECTS: 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. INTERVENTION: 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. MAIN OUTCOME MEASURES: 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.

Measurement of pruritus in a Chinese woman with pemphigoid gestationis using a wrist movement detector.

Pemphigoid gestationis (PG) is a rare itching bullous disease of pregnancy and the postpartum period. We describe the use of a new methodology for measuring the nature and intensity of itching in a 21-year-old woman with pemphigoid gestationis. At 19 weeks gestation, she developed an itchy rash over the limbs, which spread to the trunk. Blisters then appeared on the hands which subsequently also involved the feet. Intense nocturnal wrist activities in this patient, measured with a wrist monitor and defined as average acceleration in the early hours of sleep, were even higher than that in patients with severe eczema, with an average value of 181.00 +/- 43.49 (mean +/- standard error) g/min for the first three hours, versus 84.47 +/- 8.53 g/min for the group of 24 eczema subjects. Most wrist activities were slower movements at 0 to 1 Hz. This is in striking contrast to the scratching activities at 0 to 3 Hz in eczema subjects. There have been no therapeutic trials for PG. Topical steroid and oral antihistamines are usually ineffective, but worked in our patient. We also discuss the potential application of the monitor in assessing the nature of various dermatological or systemic itching disorders.

DNA-based diagnosis of xeroderma pigmentosum group C by Whole-genome scan using single-nucleotide polymorphism microarray.

In this study, we have established the molecular basis of xeroderma pigmentosum (XP) in two unrelated Chinese families. In the first patient with consanguineous parents, we mapped the disease-causing locus XPC using single-nucleotide polymorphism microarray. Mutational analysis of the XPC gene showed that the patient is homozygous for a nonsense mutation, E149X. After developing DNA-based diagnosis of XPC, we screened another XP patient for XPC mutations. We found that the second patient is a compound heterozygote of 1209delG and Q554X in this gene. These are the first XPC-causing mutations identified in Chinese patients.

Novel mutations in the PATCHED gene in basal cell nevus syndrome.

Basal cell nevus syndrome (BCNS) is an autosomal dominant disease characterized by the presence of multiple basal cell carcinomas, odontogenic keratocysts, palmoplantar pits, and calcification in the falx cerebri caused by mutational inactivation of the PTCH gene. To investigate the molecular basis of BCNS in Chinese, we did a mutational analysis of the PTCH gene by performing denaturing high-performance liquid chromatography in three BCNS families. In this study, three novel mutations, two 1-bp frameshift insertions, i.e., 1468insA and 2392insC, and one 8-bp deletion, i.e., IVS5 + 1delGTAAGTGT, affecting a donor splice site, were identified. All the mutations cause a shift of the open reading frames and lead to premature termination of PTCH protein translation. Our results showed that mutational inactivation of the PTCH gene causes BCNS in Chinese.