Resolution of pituitary microadenoma after coronavirus disease 2019: a case report

BACKGROUND: This report describes the case of a patient whose pituitary microadenoma resolved after he contracted coronavirus disease 2019. To our knowledge, this is one of the first reported cases of pituitary tumor resolution due to viral illness. We present this case to further investigate the relationship between inflammatory response and tumor remission. CASE PRESENTATION: A 32-year-old man in Yemen presented to the hospital with fever, low blood oxygen saturation, and shortness of breath. The patient was diagnosed with coronavirus disease 2019. Past medical history included pituitary microadenoma that was diagnosed using magnetic resonance imaging and secondary adrenal insufficiency, which was treated with steroids. Due to the severity of coronavirus disease 2019, he was treated with steroids and supportive care. Three months after his initial presentation to the hospital, brain magnetic resonance imaging was performed and compared with past scans. Magnetic resonance imaging revealed changes in the microadenoma, including the disappearance of the hypointense lesion and hyperintense enhancement observed on the previous scan. CONCLUSIONS: Pituitary adenomas rarely undergo spontaneous resolution. Therefore, we hypothesized that tumor resolution was secondary to an immune response to coronavirus disease 2019.