A 25 year-old female presents with right lower quadrant pain, right flank pain, nausea, and vomiting. Her temperature is 39.6 degrees C. There is right CVA tenderness and RLQ tenderness. Pelvic exam is unremarkable. Urinalysis reveals pH 7.0, trace protein, negative glucose, negative ketones, positive blood, and positive nitrates. Specific gravity is 1.022. Microscopic shows 102 RBCs/HPF, 50-75 WBCs/HPF, rare epithelial cells, and WBC casts. The most likely diagnosis is
A. acute salpingitis.
B. nephrolithiasis.
C. acute pyelonephritis.
D. appendicitis. EXPLANATIONS (u) A. Pheochromocytoma may lead to hypercalcemia but the patient does not have any signs or symptoms suggestive of pheochromocytoma, such as hypertension, headache, profuse sweating,or weight loss. (u) B. Adrenal insufficiency, Addison's disease, would reveal, in addition to the hypercalcemia,anorexia, nausea and vomiting, weight loss, and cutaneous hyperpigmentation, none of which areevident in this patient. (c) C. The majority of patients with hyperparathyroidism are asymptomatic. Recurrent nephrolithiasis may be one of the presentations of primary hyperparathyroidism. Measurement of parathyroid levels would be the initial laboratory test for the evaluation of hypercalcemia. (a) D. Hypercalcemia may be the earliest manifestation of a malignancy and this must be investigated. Most often the signs and symptoms of a malignancy will cause the patient to seek medical care. Malignancy is the second leading cause of hypercalcemia, behind hyperparathyroidism. Nulliparity is a risk factor for breast cancer and the most common presenting sign in a breast mass. Explanations (u) A. Paget's disease of bone presents with bone pain, kyphosis, bowed tibias, large head, and deafness. The initial lesions are destructive and radiolucent. Paget's disease has a normal serum calcium and phosphate, but the serum alkaline phosphatase is elevated. (c) B. Osteoporosis presents with varying degrees of back pain and loss of height is common. The serum calcium, parathyroid hormone, phosphorus, and alkaline phosphatase are normal. Xray findings demonstrate demineralization in the spine and pelvis. (u) C. Chondrocalcinosis is the presence of calcium-containing salts in articular cartilage and is commonly seen in hyperparathyroidism, diabetes, hypothyroidism, and gout. (u) D. Hyperparathyroidism is frequently asymptomatic. Serum parathyroid hormone and serum calcium are elevated. X-ray findings include demineralization, subperiosteal resorption of bone especially in the radial aspects of the fingers.