Mohs Micrographic Surgery With Immunohistochemistry for the Treatment of Periocular Melanoma In Situ.

PURPOSE: Mohs micrographic surgery with immunohistochemistry allows for same-day comprehensive margin assessment of melanoma in situ prior to subspecialty reconstruction. This study describes the oncologic and reconstructive outcomes of eyelid and periorbital melanoma in situ and identifies risk factors for complex reconstructive demands. METHODS: Retrospective case series of all patients treated with Mohs micrographic surgery with immunohistochemistry for melanoma in situ affecting the eyelids or periorbital region from 2008 to 2018 at a single institution. Tumors were assigned to the eyelid group if the clinically visible tumor involved the skin inside the orbital rim. Reconstructive variables were compared between the eyelid and periorbital cohorts. RESULTS: There were 24 eyelid and 141 periorbital tumors included. The initial surgical margin for all tumors was 5.34 ± 1.54 mm and multiple Mohs stages were required in 24.2% of cases. Eyelid tumors included more recurrences (p = 0.003), and the average defect size was larger (14.0 ± 13.3 cm2 vs. 7.7 ± 5.4 cm2, p = 0.03). Risk factors for complex reconstruction included: initial tumor diameter >2 cm (odds ratio [OR]: 3.84, 95% confidence interval [CI]: 1.95-7.57) and eyelid involved by initial tumor (OR: 4.88, 95% CI: 1.94-12.28). At an average follow-up of 4.8 years, there were no melanoma-related deaths and 1 local recurrence (0.6% recurrence rate). CONCLUSIONS: Mohs micrographic surgery with immunohistochemistry achieves excellent local control rates for periocular melanoma in situ. An initial surgical margin of 5 mm is frequently insufficient to achieve clear margins. The resulting defects are large, and the complexity of reconstruction can be predicted by tumor size and clinical involvement of eyelid skin.

Quantity and duration of exposure to general anesthesia for pediatric patients with retinoblastoma.

PURPOSE: To quantify the duration of anesthesia required for optimal management of retinoblastoma (Rb), stratified by clinical factors. METHODS: The medical records of Rb patients treated at Phoenix Children's Hospital between January 2011 and January 2022 were reviewed retrospectively. Demographic, tumor, and treatment data were collected. Anesthesia time was recorded for procedures requiring general anesthesia, including intra-arterial chemotherapy (IAC), enucleation, brainstem auditory evoked response testing (BAER), port placement, magnetic resonance imaging (MRI), and examination under anesthesia (EUA). Descriptive statistics were used to summarize patient and clinical characteristics. RESULTS: Total anesthesia time was 48,991 minutes for 610 procedures in 43 patients. The median follow-up time was 36 months (range, 12-114 months). Average anesthetic durations per exposure were 274, 152, 81.8, 62.5, 60.7, and 45 minutes for IAC, enucleation, BAER, port placement, MRI, and EUA, respectively. Patients with bilateral Rb underwent a median of 1,659 minutes of total anesthesia, compared with 397 minutes for those with unilateral disease. In patients with unilateral Rb, median total anesthesia time was 2,651, 1681, 312, 397 minutes for International Classification of Retinoblastoma grades B, C, D, and E tumors, respectively. Patients who received IAC as their primary treatment had the highest median anesthesia duration (2,100 minutes), followed by systemic chemo (654 minutes) and enucleation (289 minutes). CONCLUSIONS: Treatment of Rb requires prolonged and repeated exposure to general anesthesia. Future studies are required to determine the potential effects of these childhood anesthetic exposures.

BRAF Immunohistochemical Studies of Pediatric Conjunctival Lesions.

PURPOSE: The purpose of this study was to analyze the prevalence of an activating mutation in the B-Raf proto-oncogene (BRAF) V600E immunoreactivity in pediatric conjunctival lesions. METHODS: This retrospective case-control study included 32 pediatric patients who underwent surgical excision of conjunctival lesions between Jan 2019 and May 2022. The collected data included demographic data, clinical features, and histopathologic characteristics of the lesion, including BRAF V600E positivity. The Student t test and the Fisher exact test were used to determine the significance of the associations between clinical variables and BRAF positivity. RESULTS: BRAF immunoreactivity was positive in 11/32 lesions (34%). Age at diagnosis did not correlate with BRAF positivity, with a mean age at diagnosis of 131.7 months for patients with BRAF+ lesions and 134.7 months for those with BRAF- lesions (P > 0.1). No clinical or pathological features were found to be significantly correlated with BRAF positivity, although there was a trend toward BRAF positivity in the presence of cysts (P = 0.072). CONCLUSIONS: BRAF reactivity was present in approximately one-third of pediatric conjunctival nevi but does not correlate significantly with unique clinical or histopathological features.