RESUMO
Our aim is to describe the association between colorectal cancer (CRC) and humoral hypercalcemia of malignancy (HHM). Causes of hypercalcemia of malignancy include parathyroid hormone-related peptide (PTHrP) secretion, local osteolysis, calcitriol production and ectopic parathyroid hormone (PTH) secretion. Hypercalcemia of malignancy in patients with CRCs is a rare scenario. A patient with anal squamous cell carcinoma was admitted with hypercalcemia, suppressed PTH and hypophosphatemia. He was found to have metastatic anal squamous cell carcinoma to the liver. Further evaluation revealed elevated PTHrP and 1,25-dihydroxyvitamin D and low 25-hydroxyvitamin D. Over a 5-month course, the hypercalcemia responded poorly to bisphosphonates, transiently to prednisone, but showed marked improvement with chemotherapy. A review of English language publications in Pubmed and a reference search of retrieved articles revealed 29 cases of CRC causing PTHrP-mediated hypercalcemia. Most patients were middle-aged men (mean ± SD: 56.7 ± 13.4 years), with advanced metastatic cancer (85% with hepatic metastasis) and severe hypercalcemia (mean ± SD: 15.6 ± 1.9 mg/dL, 62% with Ca > 14). This condition is associated with high mortality (79%) and short survival (median 54.5 days, CI: 21 - 168). Despite being uncommon, HHM (PTHrP-mediated) should be considered in patients with metastatic CRC presenting with hypercalcemia. Clinicians should be aware that combined etiologies may be present, particularly in cases of resistant hypercalcemia. Treatment of the underlying malignancy is essential for calcium control.
RESUMO
Fever of unknown origin (FUO) is not infrequently a diagnostic dilemma for clinicians. Common infectious causes include endocarditis and abscesses in adults, and noninfectious causes include neoplasms and certain collagen vascular diseases, for example, polymyalgia rheumatica, various vasculitides, and juvenile rheumatoid arthritis (adult Still's disease). Subacute thyroiditis is a rare cause of FUO. Among the infectious causes of FUO, typhoid fever is relatively uncommon. We present a case of FUO in a traveler returning from India whose initial complaints were that of left-sided neck pain and angle of the jaw pain, which initially suggested the diagnosis of subacute thyroiditis. After an extensive FUO workup, when typhoid fever is a likely diagnostic possibility, an empiric trial of anti- Salmonella therapy has diagnostic and therapeutic significance. The presence of relative bradycardia, and response to quinolone therapy, was the basis of the clinical diagnosis of typhoid fever as the explanation for this patients FUO. This case illustrates the diagnostic difficulties in assessing patients with FUO with few diagnostic findings.