Autism spectrum disorder (ASD) is a neurodevelopmental condition associated with difficulties in the social, communicative, and behavioral domains. Most cases of ASD arise from an unknown etiologic process, but there are numerous risk factors, including comorbidities and maternal exposures. Although it is not part of the diagnostic criteria, hearing difficulties ranging from deafness to hyperacusis are present in the majority of persons with ASD. High-functioning children with ASD have been found to have significantly slower and asymmetric auditory brainstem reflexes. Additionally, histopathological studies of postmortem brainstems in decedents who had ASD have consistently revealed significantly fewer neurons in auditory nuclei compared with those in people who did not have ASD. The authors review the literature implicating auditory dysfunction in ASD along with results from human study participants and postmortem human brain tissue. Together, these results implicate significant structural and functional abnormalities in the auditory brainstem in ASD and support the utility of auditory testing to screen for ASD.

obstructing medium-sized mass that was partially circumferential involving one-third of the lumen (Figure 1b). A biopsy of the lesion was taken using cold-forceps. The pathology stained positive for S100 consistent with melanoma. The diagnosis of anorectal melanoma was made, and colorectal surgery was consulted. The patient was deemed not to be a surgical candidate secondary to age and active COVID-19 infection. Oncology was consulted, and it was decided to start the patient on radiation and immunotherapy with a PD-1 inhibitor. Discussion: The symptoms of anorectal melanoma can be subtle and in this case report completely asymptomatic. Symptoms to be aware of are rectal bleeding and tenesmus. Diagnosing melanoma on sigmoidoscopy can be challenging as most tumors are not pigmented. Biopsies should be taken and sent for immunohistochemical staining for S100, if positive the patient should have a PET scan. Treatment choices for the tumor are based on staging. In a resectable tumor sphincter-saving local excision with radiotherapy to the site of the tumor and the pericolic and inguinal lymphatics is recommended. For unresectable tumors or tumors with distant metastasis, immunotherapy with PD-1 inhibitors (nivolumab and ipilimumab) is an emerging treatment choice.[2578] Figure 1. CT scan and sigmoidoscopy of Rectal Melanoma.