A Case of Scleroderma With Coexisting Multiple Myeloma and Bullous Pemphigoid.

An 83-year-old female patient presented to our nephrology outpatient clinic with complaints of weakness, edema, abdominal pain, and constipation, with a preliminary diagnosis of chronic kidney failure related to heart failure. The patient had undergone mitral valve replacement surgery 10 years prior and was diagnosed with chronic renal failure six years prior. Laboratory tests revealed mild normochromic normocytic anemia, consistently high erythrocyte sedimentation rate (ESR) above 100 mm/h, and nephrotic-range proteinuria, prompting suspicion of multiple myeloma. Further investigations, including bone marrow aspiration, confirmed the diagnosis of multiple myeloma. During follow-up, the patient began to complain of difficulty swallowing and symptoms of microstomia. Upon further questioning, it was discovered that these symptoms had been present for more than 10 years. Immunoblot tests revealed positive centromere protein B (CENP-B), suggesting a diagnosis of scleroderma. Subsequently, during follow-up, bullous lesions appeared on the patient's chest. Biopsy samples confirmed a diagnosis of bullous pemphigoid (BP). The co-occurrence of scleroderma, multiple myeloma, and superimposed BP represents a rare and noteworthy case for publication.