Renal Hemorrhagic Actinomycotic Abscess in Pregnancy
A 20-year-old Puerto Rican woman, G2P0101, was referred to us at 24 weeks gestation for evaluation of an 11 cm right upper quadrant mass and anemia. She reported a history of cholelithiasis, childhood seizure disorder, left upper extremity embolectomy and a laparoscopic appendectomy in prior pregnancy at six weeks gestation, although operative and imaging records were unavailable. Her previous delivery was a Cesarean section. She had no history of poor dentition or intrauterine device (IUD) use. One month before admission to our hospital, she reported fatigue, 25 pound weight loss over six months, and severe right-sided pain. At another hospital, she underwent right upper quadrant and renal ultrasound revealing stones and sludge in the gallbladder. Ultrasound noted an 8×9×11 cm hemorrhagic mass in the right renal subcapsular area extending to the right diaphragm. At this time, differential diagnosis included angiomyolipoma with hemorrhagic rupture, renal carcinoma, lymphoma, metanephric adenoma and renal/pelvic tuberculosis. Chest radiograph was within normal limits. Her hemoglobin was initially 7 g/dL and increased to 12 g/dL after 2 units packed red blood cells. Creatinine was 0.6 mg/dL. Tuberculin skin test was negative. Urology and medical oncology consultations were obtained. She was managed with nil per os (NPO) status, analgesics, and additional two units of packed red blood cells after her hemoglobin decreased to 8.8 g/dL over four days.\nA non-contrast magnetic resonance imaging (MRI) of the abdomen and pelvis was obtained to further characterize the mass and to identify any possible renal vasculature anomalies. MRI showed an 11.2×7.7 cm right renal mass (). She developed preterm contractions and received nifedipine and a betamethasone course for fetal lung maturity. Her cervical exam remained unchanged. An ultrasound-guided right kidney biopsy of medulla and cortex revealed mild to moderate patchy interstitial inflammation with no evidence of malignancy. Immunochemical staining for kappa and lambda light chain and periodic acid Schiff staining demonstrated lymphoplasmacytic infiltrate, indicating acute interstitial nephritis, however renal function was normal. Differential diagnosis based on pathological studies included angiomyolipoma and interstitial inflammation secondary to unbiopsied renal mass with less likely possibility of renal carcinoma, lymphoma and metanephric adenoma. Given the inconclusive biopsy with no indication of malignancy, stable hemodynamic status and advanced gestation, the multi-disciplinary team recommended expectant management with close monitoring for mass size change and hemodynamic status. On hospital day 19, patient was discharged home. Interval MRIs showed stable size of the mass throughout her pregnancy. At 35 weeks gestation, the patient was admitted for preterm labor. She underwent a vacuum assisted vaginal delivery of a 2595-gram male infant. Placenta pathology showed mature third trimester placenta without evidence of inflammation or infection. The presumptive diagnosis of the mass was angiomyolipoma with hematoma as there are many reports of ruptured angiomyolipoma with hemorrhage in the obstetric literature; the plan was to repeat the MRI study six weeks post-partum.\nTwelve days after delivery, the patient returned with fever, right flank pain and leukocytosis of 19.7 K/UL. She was taken to the operating room where she underwent a right renal exploration, resection of retroperitoneal mass and partial nephrectomy. The pathology report revealed xanthogranulomatous pyelonephritis with occasional clusters of actinomyces infection (). Her operation was complicated by an unsuspected duodenal injury necessitating exploratory laparotomy and repair two days later. Pathology from resection of duodenal mass showed abscess, granulation tissue and xanthogranulomatous inflammation without evidence of actinomycotic infection. Multiple pelvic fluid collections were treated with percutaneous drains inserted by interventional radiology. She was started on piperacillin/ tazobactam then switched to amoxicillin/clavulanate for six months. Subsequent computerized tomography (CT) imaging showed complete resolution of mass.