A 44-year-old woman comes to the emergency department due to acute-onset, severe, right lower quadrant abdominal pain, nausea, vomiting, and hematuria over the last 4 hours. She had a similar episode of acute pain a year ago, but it resolved in a few hours and she did not seek medical intervention. The patient has no other medical conditions and takes no medication. She smokes a pack of cigarettes daily. She is sexually active and has never been pregnant. Temperature is 36.9 C (98.4 F), blood pressure is 140/90 mm Hg, and pulse is 102/min. There is mild tenderness to deep palpation in the right lower quadrant. Laboratory results are as follows: Which of the following is the most likely cause of this patient's current condition?

Question

A 44-year-old woman comes to the emergency department due to acute-onset, severe, right lower quadrant abdominal pain, nausea, vomiting, and hematuria over the last 4 hours.  She had a similar episode of acute pain a year ago, but it resolved in a few hours and she did not seek medical intervention.  The patient has no other medical conditions and takes no medication.  She smokes a pack of cigarettes daily.  She is sexually active and has never been pregnant.  Temperature is 36.9 C (98.4 F), blood pressure is 140/90 mm Hg, and pulse is 102/min.  There is mild tenderness to deep palpation in the right lower quadrant.  Laboratory results are as follows:  Which of the following is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

11ec160b_3a3b_a015_9249_63502d16711f_MD0001_00 This patient has recurrent abdominal pain, vomiting, and hematuria. In conjunction with hypercalcemia and hypophosphatemia, this presentation suggests ureterolithiasis due to hyperparathyroidism. Most kidney stones are made up of calcium salts and are idiopathic, but conditions that increase calcium excretion increase the risk of stone formation. Primary hyperparathyroidism leads to increased bone resorption, decreased urinary phosphate reabsorption, and increased 1,25-dihydroxyvitamin D formation, all of which result in hypercalcemia and hypophosphatemia. Despite the increased fractional reabsorption of calcium induced by PTH, net urinary calcium excretion is elevated due to the increased filtered calcium load, raising the risk for stone formation. Pain from ureterolithiasis, which occurs when the stone obstructs renal drainage, typically waxes and wanes. Obstruction at the ureteropelvic junction normally presents with flank or upper abdominal pain, whereas an obstructing stone at the ureterovesical junction usually presents with lower abdominal or groin pain. Other common symptoms include hematuria, nausea, and vomiting. (Choices A and B) Appendicitis presents with acute periumbilical or right lower quadrant pain and tenderness, but it would not usually cause recurrent symptoms. Acute diverticulitis can cause recurrent lower abdominal symptoms but is much more common on the left and typically occurs in older (age >60) patients. Neither of these conditions are associated with hematuria or hypercalcemia. (Choice C) Glomerulonephritis is a category of kidney disorders characterized by hematuria, typically with red cell casts. Common associated features include hypertension, oliguria, and acute renal failure. Patients with various nephritic syndromes may have moderate flank pain, but acute, severe lower abdominal pain is not consistent with glomerulonephritis. (Choice D) Ovarian torsion can present with acute, severe lower abdominal or pelvic pain. It can be recurrent but would not cause hematuria. (Choice E) Renal cell cancer can cause hematuria and hypercalcemia; however, pain (if present) typically presents in the flank rather than the lower abdomen. (Choice F) Renal infarction typically occurs due to acute obstruction of the renal arteries (eg, cardiac thromboembolism, aortic dissection). Patients often develop abdominal pain and hematuria but also typically have fever and marked hypertension (due to renin release). In addition, renal infarction is not associated with hypercalcemia or hypophosphatemia. Educational objective: Most kidney stones are made of calcium salts and are idiopathic, but conditions that increase renal calcium excretion can increase the risk of stones. Hyperparathyroidism is a common cause of recurrent kidney stones and is typically associated with mild hypercalcemia and hypophosphatemia. __________ References: Renal stones and calcifications in patients with primary hyperparathyroidism: associations with biochemical variables. (http://www.ncbi.nlm.nih.gov/pubmed/22474170)

A 44-Year-Old Woman Comes to the Emergency Department Due to Acute-Onset