Myxoid onychomatricoma: an unusual variant of a rare nail unit tumor.

A 57-year-old woman presented with a 3-year history of a thickened, yellowed, over-curved nail plate of the left second toe. The proximal nail fold had an associated nodule. When observed head-on, the distal nail plate demonstrated multiple circular perforations. Avulsion of the nail plate revealed a 0.7 cm pale white mass within the proximal nail matrix, which was excised. Histologic sections of the nail plate showed longitudinal cystic spaces associated with papillary projections of nail matrix epithelium. The parenchyma of the lesion demonstrated bland-appearing spindled cells in a prominent myxoid stroma with abundant mast cells. The spindled cells were focally positive for CD34 and factor XIIIa and negative for S100, pan-cytokeratin, desmin, smooth muscle actin, epithelial membrane antigen, and MART-1. Onychomatricoma (OM) is a rare nail unit biphasic fibroepithelial tumor with multiple radiating digitations lined by papillomatous matrix epithelium. The epithelial component is consisted of matrix cells that generate the thickened nail plate, and the digitations cause characteristic "wormwood" perforations of the nail plate. A fibrous stroma is characteristic with staining positive for CD34 and negative for CD99, epithelial membrane antigen, and S100. This case is unique with the presence of a prominent myxoid stroma associated with the fibrous component of the OM. Only 1 previous report of OM highlights a related finding of a myxocollagenous stroma. This purely myxoid variant represents a new distinct form of OM. Clinicopathologic correlation is essential to avoid confusion with other myxoid tumors such as a superficial acral myxoma, superficial angiomyxoma, or a digital myxoid cyst.

Early postoperative single treatment ablative fractional lasing of Mohs micrographic surgery facial scars: a split-scar, evaluator-blinded study.

BACKGROUND/OBJECTIVES: Despite precise surgical technique, some postoperative facial scars will depress and widen over time, likely due to weakened or inadequately replaced collagen fibers in the underlying dermis. The purpose of this study is to evaluate whether a 10,600 nm ablative carbon dioxide (CO2 ) fractional laser used early in the post-surgical setting results in improved postoperative facial scars after a single treatment session. STUDY DESIGN: A prospective randomized, comparative split-scar study was conducted on 20 subjects between the ages of 20-90. Subjects underwent Mohs surgery for nonmelanoma skin cancer of the face. Subsequent to tumor removal, subjects with a linear scar of 4 cm or greater were enrolled. On the day of suture removal, all subjects had one-half of their scar randomly selected and treated with a 10,600 nm CO2 fractional laser (energy = 10 mJ; density = 10%; spot size = 7 mm; pulse = 1). The untreated scar half served as a control. Scars were re-evaluated 12 weeks later. An independent blinded observer graded the scar halves with the Vancouver scar scale (VSS) immediately prior to treatment and 12 weeks after treatment. Subjects completed a visual analog scale (VAS) at the same time points. RESULTS: Three months after laser treatment, a significant decrease in VSS and 3 of the 4 of its individual parameters were detected in both control and treated halves of the scar. When comparing the laser group versus the control group, a statistically significant difference was not noted in VSS (P = 0.31) but a statistically significant difference in patient VAS was detected (P = 0.002). No side effects of the laser treatment were noted. CONCLUSION: Facial wounds sutured in a layered manner heal well. Patients prefer early fractional CO2 lasing of surgical scars, though use of the VSS failed to detect an objective difference between laser and control halves of scars. Conservative laser settings, a single session treatment, and VSS insensitivity for surgical scars may influence these findings.