Anal Squamous Cell Carcinoma in a Patient with Myasthenia Gravis: Is Immunosuppression the Main Underlying Etiology?

Abstract

Patients who are immunocompromised by diseasessuch as human immunodeficiency virus(HIV)infection are moreprone to develop some malignanciessuch as Kaposi's sarcoma and central nervous system (CNS) lymphomas. Historically, anal squamous cell carcinoma (SCC)was also included on thelist as an acquired immunodeficiency syndrome (AIDs)-defining cancer. Similarly,compromised immune disordersincluding severe immunosuppression, haematologic malignancies, and solid organ transplantationhave been identified as important risk factors for thedevelopment of anal SCC. Review of the medical literature showed only sporadic cases of anal SCC in patients with pre-existingmyasthenia gravis (MG), with or without thymoma. We present herea case of anal SCC in a patient with several years history of MG who was receiving intravenous immunoglobulin (IVIG).We believe thisassociation is explained by the autoimmune nature of the disease and the use of immunosuppressive medications to treat it.To further support our case, wealso present a review of the literatureassociating anal SCC with MG.