Coexisting primary early gastric plasmacytoma and sarcoidosis with hypercalcaemia.

We report on a 61-year-old woman with coexisting early stage primary gastric plasmacytoma and sarcoidosis with hypercalcaemia. Laboratory data on admission showed hypercalcaemia, with 12.8 mg/dl, parathyroid hormone-related peptide (PTHrP) 1.2 pmol/l, C-PTHrP 69.5 pmol/l, and 1,25-dihydroxyvitamin D3 46.7 pg/ml. Neoplastic plasma cells proliferated in the propria mucosa of the stomach, showed a monoclonal immunoglobulin of cytoplasmic IgA (lambda light chain) and were positive for leucocyte common antigen and epithelial membrane antigen on paraffin section prepared from a stomach biopsy specimen. Russel bodies were present, as were crystals. Abundant sarcoid granulomas were observed in many of the regional lymph nodes around the stomach and in the dermis of a skin nodule. The patient underwent subtotal gastrectomy with administration of antimyeloma chemotherapy. We suggest that the hypercalcaemia in this patient was due to PTHrP production by neoplastic plasma cells.