GRANULOMATOUS DISEASE OF UNUSUAL SITES CAUSING HYPERCALCEMIA: TWO CASE REPORTS.

OBJECTIVE: Hypercalcemia with suppressed parathyroid hormone (PTH) levels is mostly due to granulomatous disease (GD) or neoplastic disease. In GD, autonomous activity of extra-renal 1α-hydroxylase enzyme is usually the underlying cause. We describe a pair of cases where hypercalcemia resulted from GD of unusual sites posing significant diagnostic challenges. METHODS: We describe 2 cases of PTH-independent hypercalcemia due to GD of the prostate gland and the stomach. RESULTS: Both cases presented with marked hypercalcemia and suppressed PTH levels. Case 1 is an elderly male who presented with marked symptomatic hypercalcemia on multiple occasions. Investigations revealed elevated levels of 1,25-dihydroxyvitamin D3 and prostate-specific antigen but normal PTH-related protein. Transrectal biopsy of the prostate gland confirmed the presence of chronic granulomatous prostatitis. The patient responded very well to steroids which entirely normalized his calcium level. Case 2 is a male who presented similarly with significant hypercalcemia but had upper gastrointestinal symptoms and anemia at onset. Endoscopy and biopsy established the presence of granulomatous gastritis likely due to Crohn disease which responded to steroids resulting in normalization of calcium levels within a short span of time. CONCLUSION: While the majority of PTH-independent hypercalcemia cases are due to GDs of lymph nodes or malignancy, our cases indicate that in uncertain cases, granulomatous processes involving unusual sites should be considered in the evaluation of hypercalcemia with suppressed PTH.

Retroperitoneal Fibrosis as a Cause of Chylous Ascites.

Retroperitoneal fibrosis is a rare condition characterized by chronic inflammation and marked fibrosis of the retroperitoneal tissue, often leading to entrapment of abdominal organs. We report a 69-year-old white man who presented with a 5-week history of gradual onset of progressive abdominal distension. He had no history or risk factors for an underlying liver condition. Ascites and a retroperitoneal mass encasing the major abdominal vessels were revealed on imaging. Biopsies of the mass confirmed the presence of retroperitoneal fibrosis, and the ascitic fluid was milky, consistent with chylous ascites. We discuss this rare presentation and the challenges of treatment for chylous ascites caused by RPF, including the role for supportive treatment.

FDG Uptake by Prosthetic Arterial Grafts in Large Vessel Vasculitis Is Not Specific for Active Disease.

OBJECTIVES: This study investigated the incidence and clinical significance of arterial graft-associated uptake of fluorodeoxyglucose in large-vessel vasculitis (LVV). BACKGROUND: The role of 18F-labeled fluorodeoxyglucose-positron emission tomography/computed tomography ([18F]FDG-PET/CT) in the management of LVV remains to be defined. Although [18F]FDG uptake at arterial graft sites raises concerns regarding active arteritis or infection, its clinical significance in LVV has never been formally studied. METHODS: An observational prospective study sought to identify patients with Takayasu arteritis (TA) undergoing [18F]FDG-PET/CT more than 6 months after graft surgery from a large cohort of patients from 2 tertiary referral centers. [18F]FDG uptake by the graft and native arteries was scored on a scale of 0 to 3 relative to hepatic uptake, and periprosthetic maximum standardized uptake value (SUVmax) was calculated. Periprosthetic [18F]FDG uptake in active disease was compared with that in inactive disease, and arterial progression was assessed by prospective magnetic resonance angiography (MRA). RESULTS: Twenty-six subjects with TA were enrolled. All were afebrile with negative blood culture. Periprosthetic uptake was significant in 23 of 26 patients, and the mean SUVmax was 4.21 ± 1.46. Median periprosthetic [18F]FDG uptake score (3; interquartile range [IQR]: 3 to 3) was higher than in native aorta (1; IQR: 0 to 1; p < 0.001). Graft-specific [18F]FDG uptake was unrelated to disease activity. Despite the high frequency of graft-associated [18F]FDG uptake, sequential MRAs did not reveal arterial progression in 25 of 26 patients; the 1 remaining case showed minor progression limited to native arteries. Nine patients underwent repeated PET/CT scanning without showing changes in graft-specific uptake, despite increased treatment. CONCLUSIONS: Significant [18F]FDG uptake that is confined to arterial graft sites in patients with LVV does not reflect clinically relevant disease activity or progression. To minimize exposure to immunosuppression and in the face of negative blood culture, clinically quiescent arteritis, normal or stably raised C-reactive protein levels, we elected not to escalate treatment and monitor progression with MRA.