Membranous nephropathy, leiomyoma and autoimmune myasthenia: more than a coincidence?

Secondary Membranous Nephropathy Due to Benign Tumors in 2 Young Women: A Case Report

Membranous nephropathy (MN) is one of the most common causes of adult-onset nephrotic syndrome. We describe the cases of 2 young women in their 20s presenting with nephrotic syndrome due to antiphospholipase A₂ receptor (anti-PLA₂R)–negative MN, that was found to be associated with benign tumors. Both women had no extrarenal symptoms of a connective tissue disease, infection, or malignancy. They both had been previously healthy and were not receiving treatment with any drugs. Both had MN on kidney biopsy. Biopsies were negative for PLA₂R antigen, and their serum did not demonstrate the presence of anti-PLA₂R antibodies. Both were investigated for a secondary cause on the basis of negative anti-PLA₂R serology and biopsy features supportive of secondary MN and were found to have benign tumors on radioimaging: a uterine leiomyoma and mesenteric fibromatosis, respectively. In both instances, the nephrotic syndrome remitted following resection of the tumors. To our knowledge, uterine leiomyoma and mesenteric fibromatosis have not previously been described in association with MN. These cases highlight the importance of pursuing a secondary cause of MN in patients without anti-PLA₂R antibodies in serum or PLA₂R antigen on kidney biopsy.

Non-motor Comorbidity of Myasthenia Gravis: Myasthenia Gravis as a Systemic Immunological Disorder Involving Non-motor Systems

To explore non-motor comorbidities of myasthenia gravis (MG), we present two cases of thymoma-associated MG patients. Alopecia, pure red cell aplasia, and thymoma- associated multiorgan autoimmunity were observed in Case 1, and alopecia, thrombocytopenia, hypogammaglobulinemia and nephrotic syndrome were observed in Case 2. In both cases, autoreactive T lymphocytes inappropriately stimulated by thymus tissue may have played key roles in generating the various autoimmune-associated symptoms. Consequently, systemic immunological involvement due to the thymoma-associated breakdown of immunoregulations in both motor and non-motor systems should be considered in MG patients.

Progressive Encephalomyelitis with Rigidity and Myoclonus Resolving after Thymectomy with Subsequent Anasarca: An Autopsy Case

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is an autoimmune disorder involving the brainstem and spinal cord and is sometimes associated with thymoma. We encountered a 75-year-old woman with typical PERM features, glycine receptor antibody, and thymoma. Her neurologic symptoms improved after thymectomy, but she unexpectedly developed anasarca with massive pleural effusions and hypoalbuminemia and finally succumbed to death. The autopsy showed edema and mononuclear infiltration in the pleura but no neuropathological findings typical of PERM. Effective treatment of PERM can reverse the neuropathological signs of encephalomyelitis. The autoimmune nature of anasarca is possible but not proven.