Endocrine Abstracts

Case history: An 81 years old lady with treated follicular lymphoma, hypertension and osteoporosis was admitted to hospital with a fall and was found to have hypercalcaemia with adjusted calcium of 4.9 mmol/l (nr 2.2–2.6 mmol/l). There was history of constipation but no history of excessive thirst or polyuria. The patient was on atorvastatin, amlodipine, bendroflumethiazide, ramipril, calcium and vitamin D. On examination our patient was dehydrated and mildly confused. There was no palpable neck swelling and rest of the clinical examination was normal.

Investigations and results: Biochemical profile revealed persistently elevated adjusted calcium ranging between 3.5 and 4.9 mmol/l (2.2–2.6), phosphate 4.8 mmol/l (3.4–4.5), PTH 1 pmol/l (1.6–6.9), urea 10.6 mmol/l (2.5–7.5), Creatinine 152 umol/l (59–104) and Vitamin D 40 nmol/l (50 – 125). Multiple myeloma screen, serum angiotensin converting enzyme (ACE) and anti-neutrophilic cytoplasmic antigen (ANCA) were negative. Hypercalcaemia due to malignancy was suspected and the patient underwent CT chest, abdomen and pelvis which did not reveal any evidence of malignancy. Our patient then underwent whole body PET scan which showed 17 + 11 + 8 cm FDG avid mass encasing the left femoral shaft. MRI left femur confirmed the mass and the differential diagnosis was either soft tissue sarcoma or lymphoma. Biopsy of the soft tissue mass revealed a diffuse large B cell lymphoma.

Treatment: Thiazide diuretic and calcium and vitamin D supplements were stopped, and our patient received intravenous fluids. The calcium levels did not normalise with intravenous fluids, however the patient developed sign of heart failure. Frusemide was added on which improved heart failure but had minimal effect on calcium. The patient received intravenous pamidronate and because calcium levels remained high, our patient needed further doses of intravenous Pamidronate over the next 4 weeks. Calcium responded only marginally to pamidronate treatment. Our patient needed 2 doses of desnoumab without significant response. Calcitonin was given with only modest improvement of calcium levels (3.5 mmol/l). After biopsy confirmed the left thigh mass to be a diffuse large B cell lymphoma, prednisolone 1 mg/kg was started.

Conclusion and points for discussion: 1. Our case report describes the diagnostic and management challenges in the context of resistant hypercalcaemia. 2. Consider underlying malignancy in the presence of severe resistant hypercalcaemia. 3. We are of the opinion that hypercalcaemia in our patient may settle once lymphoma is treated.