Abstract
INTRODUCTION: Sarcoidosis is a rare disease primarily affecting the pulmonary system in approximately 90% of cases. (1) Cutaneous involvement occurs in 20-35% of sarcoidosis patients and can present without systemic manifestations (2). The skin is the second most commonly affected organ after the lungs in sarcoidosis (3). CLINICAL CASE: We report a unique case of cutaneous sarcoidosis presenting with asymptomatic hypercalcemia. An 81-year-old White British woman with a medical history of type 2 diabetes mellitus, anemia, hypertension, and polymyalgia rheumatica (PMR) was managed for left leg cellulitis. Examination revealed a systolic murmur, clear chest, bilateral erythema, raised temperature, and pitting edema at the infection site. An admission chest x-ray showed a known large hiatus hernia. Routine blood tests revealed adjusted calcium levels of 3.52 mmol/L (2.20-2.60 mmol/L), and PTH levels were low at 0.9 pmol/L (1.6-6.9 pmol/L), indicating PTH-independent hypercalcemia. Further blood tests showed normal vitamin D (129nmol/L, n>50nmol/L), ACE levels (<5 IU/L), and thyroid funct,on tests (TSH 7.17mU/L, n0.30-4.20mU/L, T4 15.6pmol/L, n11.9-21.6pmol/L, TPO antibody<10IU/mL, n0-34). Myeloma screen (no monoclonal bands, Serum Kappa Free Light Chain:31.03 mg/L,n 3.30 - 19.40; Serum Lambda Free Light Chain:22.57 mg/L,n:5.71 - 26.30) and autoimmune screens (IgG:7.8 g/L,n:6.0 - 16.0; IgA:1.26 g/L,n:0.80 - 4.00; IgM*0.41 g/L,n:0.50 - 2.00) were negative. Elevated 1,25-dihydroxy vitamin D (calcitriol) was noted at 246 pmol/L. Occult malignancy was ruled out via normal CT chest, abdomen, and pelvis, gastroscopy with biopsy, and CT head scans. Initial PET CT results were reported as normal. Hypercalcemia management included intravenous fluids, zoledronic acid, denosumab, steroids, and cinacalcet. Subsequent detailed PET CT report revealed extensive moderate FDG uptake in the subcutaneous tissue of both arms. Physical examination identified subcutaneous nodules, and histology confirmed a florid dermal non-necrotizing granulomatous reaction, diagnosing extra-pulmonary cutaneous sarcoidosis. Interestingly, the patient had been on long-term prednisolone (10 mg) for PMR, recently reduced to 4 mg prior to admission. Her calcium levels normalized (2.57 mmol/L) after weaning off prednisolone. CONCLUSION: Hypercalcemia in cutaneous sarcoidosis without pulmonary involvement is rare. Long-term follow-up is essential, as patients with cutaneous sarcoidosis may develop systemic involvement. She was referred to pulmonary and dermatology specialists for further evaluation.