Paraneoplastic Pemphigus in a Patient with Carcinosarcoma of the Uterus

Case Presentation The patient is a 68-year-old female with hypertension, chronic obstructive pulmonary disease, without medical follow-up for several years, who initially presented with skin blisters and orallesions, which were biopsied by her dermatologist and found tobe bullous pemphigoid. She was treated with a course of oral prednisone and had resolution of her skin and oral lesions. Threemonths later, she presented with a swollen leg and was diagnosed with a deep venous thrombosis, for which she was started on coumadin and had an inferior vena cava filter placed. She then had hemoptysis a few days later, after which the coumadin washeld. A chest computed tomography (CT) done at that time founda right middle lobe consolidation consistent with aspiration pneumonia and a cavitary lesion in the left upper lobe of her lung, which was biopsied and found to be a necrotizing cavitarylung lesion. After being ruled out for tuberculosis, she had an outpatient positron emission tomography (PET) scan which waspositive for a 2.7cm left lower lobe cavitary lesion and a 9 cm pelvic mass with hypermetabolic activity, as well as small liver lesions. Concurrently, she complained of dysphagia and 30-lbs ofweight loss over the prior six months, so the decision was madeto undergo an outpatient esophagogastroduodenoscopy (EGD).The EGD could not be completed secondary to a stricture in thedistal esophagus; however, pemphigus ulcers were seen in the mouth and esophagus. Given the patient’s degree of malnourishmentand dehydration, she was admitted to the outside hospital. On admission, she was found to have leukocytosis with a white blood cell count of 37,000/L, hypercalcemia with acalcium of 13mg/dL, hypotension, and acute renal failure with a creatinine of 4.4mg/dL. Her parathyroid hormone-related protein (PTHrP) was 105 pmol/L (normal \u3c1.3 pmol/L), while her intact parathyroid hormone (PTH) was \u3c3pg/mL (10-55 pg/ml). A serum protein electrophoresis with immunoelectrophoreiswas positive for an IgG lambda paraprotein. On bone marrow biopsy, there were 25% plasma cells consistent with multiple myeloma, though this diagnosis was questioned after transfer. For treatment of her hypercalcemia, she was given intravenous fluids and calcitonin with minimal improvement, but with resolution of her renal failure