Endocrine Abstracts

Section 1: Case history: A 57-year-old female shop assistant presented with a four week history of increasing thirst and lethargy. The patient also reported non-specific pain in her shoulders, ribs and hips. She was otherwise well with no past medical history. Systemic enquiry was unremarkable. On examination nothing abnormal was noted. Specifically there were no rashes, lymphadenopathy or hepatosplenomegaly. Joint examination was normal and there was no muscle tenderness or weakness.

Section 2: Investigations: Initial investigations revealed an elevated calcium (2.92 mmol/l) with an acute kidney injury (eGFR 38). The PTH was suppressed (0.7 pmol/l). Myeloma screen was negative. CXR was normal with no hilar lymphadenopathy, infiltrates or masses. The calcium levels increased further despite rehydration peaking at 3.24 mmol/l. A CT TAP was undertaken but no abnormal findings were identified. A PET scan was therefore performed to exclude an occult malignancy. No focal mass was noted but there was diffuse uptake in a number of muscle groups. Creatinine kinase levels were normal. The serum ACE was raised and 1,25 (OH) 2 Vitamin D levels were elevated. A muscle biopsy was performed showing non-caseating granulomas confirming a diagnosis of systemic sarcoid with primary muscle involvement.

Section 3: Results and treatment: Once a diagnosis of sarcoid was confirmed the patient was initiated on 40 mg OD prednisolone and subsequently 20 mg weekly methotrexate was added. The patient’s serum calcium level quickly normalised following treatment and symptoms begun to resolve.

Section 4: Conclusions and points for discussion: This case describes a patient with significant hypercalcaemia due to acute atypical isolated sarcoid myositis. This case highlights an uncommon but well recognised clinical condition which is distinct from classical sarcoid. A recent case series found only 8 published cases of hypercalcaemia associated with acute isolated sarcoid myositis. In these cases, like ours, myositis was not initially suspected due to the non-specific symptoms and normal CK. All of the patients in this case series had a PET scan performed for malignancy screening incidentally revealing intense, diffuse fluorodeoxyglucose (FDG) uptake isolated to muscles. The PET scan in our case showed uptake which has previously been described as characteristic for sarcoid myositis and coined ‘The tiger man sign’. Our case highlights an uncommon but well recognised cause of hypercalcaemia which is responsive to steroids and immunosuppressive medication. PET scanning seems to be of particular utility in the detection of this condition and may be useful in monitoring treatment response.