University of Central Florida

Merkel cell carcinoma (MCC) is a dermal neuroendocrine malignancy driven by inactivation of the tumor suppressors Rb and p53 either through Merkel cell polyomavirus (MCPyV) infection or ultraviolet (UV)-induced mutations. Virus-positive MCC exhibits pure neuroendocrine morphology, low UV-induced mutational burden, retained Rb protein, and low p53 expression. Viral-negative MCC includes pure neuroendocrine carcinomas and combined tumors with squamous and neuroendocrine components. These tumors typically exhibit loss of Rb expression and either overexpression of mutated p53 or a complete absence of p53. Intraepidermal, insitu MCC (MCCis) is a rare, primarily viral-negative variant that often coexists with actinic keratosis (AK) and squamous cell carcinoma insitu (SCCis), supporting a UV-driven pathogenesis. While MCCis is hypothesized as a potential precursor to select cases of combined MCC, its p53 and Rb expression remain largely uncharacterized. We report a CM2B4-negative MCCis in an 87-year-old man associated with AK and SCCis. Compared to normal epidermis, AK and SCCis exhibited increased Rb and p53 expression, whereas MCCis demonstrated loss of expression of both tumor suppressors. These findings suggest that dual downregulation of Rb and p53 may drive select cases of MCCis in sun-damaged skin.

We introduce a free-space optical sensing architecture in which spatial refractive-index gradients are mapped directly into heterodyne modulation sidebands using a frequency-diverse beamlet array. Mutually coherent beamlets with distinct frequency offsets sample the medium at different transverse positions, producing a time-dependent interference signal on a single detector whose Fourier transform yields a comb of heterodyne beat frequencies. Spatially varying refractive index gradients induce differential phase shifts between beamlets, yielding symmetric sidebands around each beat frequency that encode the local gradient. This approach enables multiple parallel sensing channels on a single detector without a reference arm or embedded sensing elements, with spatial sampling and detection defined entirely by the optical field. An analytic framework describing beat formation and sideband scaling is developed and validated experimentally. Using an eight-beamlet array at 532 nm with 5 MHz spacing, the system achieves > 80 dB beat-to-sidelobe ratios and near-pascal acoustic sensitivity. Because the detection bandwidth is set by the optical beat frequencies, this approach supports extension to substantially higher acoustic bandwidths, establishing a compact, reconfigurable platform for remote, non-contact acoustic sensing. This approach establishes a general framework for non-contact sensing of refractive index gradients using structured light, with potential applications beyond acoustics including turbulence and thermal sensing.

Brain herniation into the dural venous sinus (BHDVS) is a rare and underrecognized imaging finding. Although often incidental, it may be associated with idiopathic intracranial hypertension (IIH), particularly in adults. Pediatric cases remain uncommon. This study presents three pediatric BHDVS cases and reviews current literature to highlight clinical relevance, imaging features, and management. Pediatric cases of BHDVS were evaluated using magnetic resonance imaging. A comprehensive literature review was conducted to summarize current knowledge on prevalence, imaging characteristics, clinical presentation, and management strategies. Case 1: A 6-year-old female with daily headaches had right occipital lobe herniation into the right transverse sinus with partial sinus filling defect, but no signs of raised intracranial pressure. Managed conservatively, follow-up imaging showed stability. Case 2: A 3-year-old male evaluated for developmental delay was incidentally found to have cerebellar herniation into the left transverse sinus. He was asymptomatic and no treatment was required. Case 3: A 3-year-old female with epilepsy had an incidental left temporal lobe herniation into the transverse sinus. The lesion was unrelated to seizures and remained stable without intervention. Very few similar cases were found in a literature review; a brief review of existing literature is presented and comparisons made between BHDVS and similar conditions. BHDVS may mimic more serious pathology. Accurate recognition of imaging, particularly in pediatric patients, is essential to prevent misdiagnosis and overtreatment. While typically managed conservatively, its association with IIH warrants further investigation. Increased awareness and continued study may refine understanding of its clinical implications.