HYPERCALCEMIA ASSOCIATED WITH ELEVATED PTHrRP IN A PATIENT WITH A CHRONIC SACRAL ULCER

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 199-237-Disorders of Parathyroid Hormone & Calcium Homeostasis
Translational
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-213
Dorothy A. Fink*, Patricia M. Raciti, Marcella D. Walker, John P. Bilezikian and Shonni J. Silverberg
College of Physicians & Surgeons, Columbia University, New York, NY
Background:  Dr. Jean-Nicolas Marjolin first described aggressive epidermoid tumors arising from areas of chronic injury such as chronic ulcers and burn wounds in 1828.  Hypercalcemia due to Marjolin’s ulcer is a rare complication and the etiology of the hypercalcemia is not well defined. 

Clinical case:  We describe a 45-year-old paraplegic African American man, paralyzed below T6 due to a gunshot wound in 1989, whose course has been complicated by chronic sacral ulcers, with biopsy confirmed osteomyelitis. Prior to admission, he moved independently in a wheelchair and could transfer from bed to chair in the nursing home. He presented with a history of weakness, fatigue, anorexia, dehydration, and 14 kilograms weight loss over approximately 2 months. He had no known history of fractures or nephrolithiasis, and denied use of thiazide diuretics, lithium, herbal supplements, or vitamins. He also had no past history of hypercalcemia.

Physical examination demonstrated a 16 cm x 27.5 cm unstageable lower back ulcer with ulceration extending to the left thigh. The ulcer had a yellow fibrinous exudate in its center. There were bilateral rock hard, tender 4 cm inguinal nodes. The patient was admitted after serum albumin-corrected calcium concentration in the Emergency Department was found to be 16.6 mg/dL (nl: 8.7-10.2). Further evaluation was remarkable for an ionized calcium: 1.71 mM/L (nl: 1.12-1.32); phosphorus: 3.0 mg/dL (nl: 2.5-4.3); blood urea nitrogen: 21 mg/dL (nl: 7-20); creatinine: 0.8 mg/dL (nl: 0.5-1.1). Intact PTH: undetectable; 25-hydroxyvitamin D: 18 ng/mL (nl: 30-80); 1,25-dihydroxyvitamin D: 11 pg/mL (nl: 15-75); alkaline phosphatase activity: 130 U/L (nl: 33-96). PTHrP was 40 pg/mL (nl: 14-27). CT of the pelvis showed the posterior decubitus ulceration; bony destruction of the medial aspect of the left ilium and ischial bones, left posterolateral aspect of the vertebral body of L5, and bilateral femoral heads; and lytic lesions in the bilateral iliac bones and lower lumbar spine. CT of the chest showed no evidence of nodal or pulmonary parenchymal metastatic disease. A sacral skin biopsy and right inguinal lymph node biopsy were performed. Pathology revealed invasive moderately differentiated squamous cell carcinoma.

Conclusion:  While past case reports have proposed humoral hypercalcemia of malignancy as a possible mechanism, to our knowledge, this is one of the first reports to document an elevated PTHrP as the likely etiology.  Acute hypercalcemia in the setting of a large, chronic ulcer should raise suspicion for an underlying Marjolin’s ulcer and a PTHrP-mediated mechanism.

Disclosure: JPB: Ad Hoc Consultant, Amgen, Investigator, Amgen, Ad Hoc Consultant, Lilly USA, LLC, Investigator, NPS, Ad Hoc Consultant, NPS, Ad Hoc Consultant, Johnson &Johnson, Ad Hoc Consultant, GlaxoSmithKline. Nothing to Disclose: DAF, PMR, MDW, SJS

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