Rhino-Orbital Mucormycosis With Delayed Diagnosis in an Immunocompromised Patient: A Case Report.

Rhinoorbital mucormycosis is a rapidly progressing invasive fungal infection associated with high mortality, primarily affecting immunocompromised patients. We present the case of a 78-year-old male patient with a history of type 2 diabetes mellitus, systemic arterial hypertension, and kidney transplantation, who was admitted for severe pneumonia due to SARS-CoV-2 at the National Institute of Medical Sciences and Nutrition "Salvador Zubirán," a care center in Mexico City. During his hospital stay, he developed a subacute left orbital lesion. The diagnosis of mucormycosis was established based on histopathological findings compatible with mucormycosis, without microbiological or molecular confirmation. Treatment consisted of liposomal amphotericin B and staged surgical debridements, avoiding orbital exenteration. Despite the complex clinical course and the absence of culture or PCR confirmation, the patient experienced satisfactory functional recovery, preserving visual acuity and without relevant aesthetic sequelae. This case, managed at a national referral hospital in Mexico, emphasizes the importance of considering mucormycosis in the differential diagnosis of orbital lesions in patients with multiple risk factors and highlights the value of a timely, multidisciplinary approach, particularly in settings with limited diagnostic resources.