Radiation-Induced Eccrine Squamous Syringometaplasia With Perineural Invasion.

ABSTRACT: Eccrine squamous syringometaplasia (ESS) is a benign metaplastic reaction of eccrine ducts that occurs in response to injury and can be a histologic mimic of squamous cell carcinoma (SCC). Reported is an 82-year-old man undergoing Mohs surgery for presumed SCC diagnosed in a field of radiation dermatitis. After 3 Mohs stages, the peculiar squamous proliferation was recognized as ESS and the procedure was aborted. Complicating the interpretation of the Mohs frozen section was the presence of perineural invasion because perineural invasion has not been previously reported to occur with ESS. The histologic features used to distinguish ESS from SCC are discussed.

Expanding Understanding of Electrocochleography in Cochlear Implantation: Auditory Neuropathy Spectrum Disorder With Normal Pure Tone Average.

Objective: Describe the preoperative decision-making, intraoperative electrocochleographic (ECoG) findings, and outcome of cochlear implantation (CI) in a patient with auditory neuropathy spectrum disorder (ANSD) and normal pure-tone thresholds. Patients: A 19-year-old with a history of hypoxic ischemic encephalopathy and seizures was referred for hearing rehabilitation in the setting of typical hearing by pure tone audiometry but poor speech understanding. A diagnosis of ANSD was made based on acoustic brainstem response (ABR), distortion product otoacoustic emission, and acoustic reflex testing. Imaging revealed no central cause of hearing impairment. Interventions: Right-sided CI. Main Outcome Measures: Preoperative and postoperative audiometric data. Intraoperative ECoG. Results: Preoperatively the patient underwent comprehensive audiologic testing with behavioral audiometry, ABR testing, and CI candidacy evaluation. In the right ear, the pure tone average (PTA) was 15 dB and word recognition score was 36%. ABR confirmed ANSD. Preoperative CNC and AzBio in quiet were 8% and 0%, respectively. Intraoperative ECoG amplitudes and audiometry showed responses in the 100 uV range and estimated PTA of 42 dB HL. Postoperative testing at 1-month post-initial activation revealed PTA of 45 dB HL and unchanged word and sentence scores. However, the patient cites an improved ability to communicate and increased confidence and averages over 14 hours of device use daily. Conclusions: To our knowledge, this is the first reported case of CI in an ear with normal PTA. Given that nearly all presently available ECoG data comes from patients with greater degrees of hearing loss, this unique case adds to our understanding of hearing preservation in CI.

Heterozygous Deletion of Chromosome 15q13.3 in a Boy with Developmental Regression, Global Developmental Delay, Hypotonia, and Short Stature.

Two causes of intellectual disability are 15q13.3 deletion syndrome and BRWD3 X-linked intellectual disability. 15q13.3 deletion syndrome causes a heterogenous phenotype including intellectual disability (ID), developmental delay (DD), autism spectrum disorder, epilepsy/seizures, schizophrenia, attention deficit hyperactivity disorder, visual defects, hypotonia, and short stature. BRWD3 variants are rare, and the clinical presentation is largely unknown. Presented here is a 34-month-old male with developmental regression, global DD, hypotonia, and short stature. In this study, the patient and his mother underwent a whole-genome array screening. Sorting intolerant from tolerant (SIFT) and polymorphism phenotyping v2 (PolyPhen-2) analyses were performed to determine the pathogenicity of the BRWD3 mutation. Array comparative genomic hybridization showed a heterozygous, pathogenic deletion of at least 1.6 Mb from the cytogenetic band 15q13.2q13.3 and a BRWD3 variant of unknown clinical significance. This combination of genetic mutations has never been reported together and neither disorder is known to cause developmental regression. The mechanism of developmental regression is undefined but is of great importance due to the opportunity to develop therapies for these patients.

Treating linear porokeratosis with topical lovastatin/cholesterol cream.

Linear porokeratosis is a rare variant of porokeratosis that is characterized by unilateral lesions along the lines of Blaschko. Like all variants of porokeratosis, linear porokeratosis is characterized by the histopathologic finding of cornoid lamellae bracketing the lesion. The underlying pathophysiology involves a two-hit post-zygotic knockdown of genes involved in mevalonate biosynthesis in embryonic keratinocytes. Although there is currently no standard or effective treatment, therapies targeted to rescue this pathway and restore keratinocyte cholesterol availability are promising. Presented here is a patient with a rare, extensive case of linear porokeratosis treated with compounded 2% lovastatin/2% cholesterol cream leading to partial resolution of the plaques.

Kaposi sarcoma: What to do with a negative human herpesvirus 8 immunohistochemical stain?

Kaposi sarcoma (KS) is an intermediate vascular sarcoma that can cause significant morbidity and mortality in patients if left untreated. It is associated with human herpesvirus 8 (HHV-8) infection. Definitive diagnosis is supported by classic histopathology including slit-like vascular spaces, spindle cells, lymphocyte infiltration, and extravasated red blood cells on H&E stain and positive immunohistochemical (IHC) staining for HHV-8. We present a challenge we encountered in detecting HHV-8 by IHC in a mucosal lesion demonstrating classic histopathology for KS.