Vitamin D-Resistant Rickets Diagnostics and Treatment Challenges at Muhimbili National Hospital, Tanzania.

Introduction. Rickets is softening of bones caused by defective mineralization of the cartilage in the epiphyseal growth plate, causing widening of the ends of long bones, growth retardation, and skeletal deformities in children. It can be classified into calciopenic and phosphopenic, each type with various subclasses. Case Presentations. We presented 2 cases, first of a 1 year and 4-month-old male, with a history of recurrent episodes of cough for 8 months and bowing of the legs 6 months prior to admission. Clinical and laboratory investigation was suggestive of vitamin D-dependent rickets, and he started vitamin D treatment with minimal response. The second case is of a 4 years and 7-month-old male who presented with developmental delay, poor weight gain, and recurrent chest infection and worsening of bone pain since 9 months of age. Laboratory investigation was suggestive of phosphopenic rickets, and he was started on treatment at 9 months of age with little improvement and at 4 years, he sustained multiple fractures and succumbed to severe respiratory tract infection and died at 4 years and 7 months of age. CONCLUSION: Rickets pose a diagnostic and treatment challenge in resource-limited countries, and clinical judgment and early initiation of treatment are important.

Case report: Xanthogranulomutous pyelonephritis presenting as "Wilms' tumor".

BACKGROUND: Xanthogranulomatous pyelonephritis (XGP) is a rare renal tumor that arises as a complication of chronic obstructive pyelonephritis of uncertain etiology. It is primarily an adult tumor seen occasionally in children associated with urinary tract obstruction due to congenital urological anomalies, nephrolithiasis, and recurrent urinary tract infections. Radiologically, it may show neoplastic features such as those seen in common pediatric renal malignancies like wilms' tumor and renal cell carcinoma. This overlap in radiological manifestation frequently leads to misdiagnosis and delay in appropriate intervention. We report a case of a 3 years old boy who presented with history of recurrent urinary tract infections and a left renal mass initially thought to be Wilms' tumor. CASE PRESENTATION: We present a case of a 3 years old boy admitted to the Pediatric oncology unit at Muhimbli National Hospital in Dar es Salaam, Tanzania with one year history of recurrent fever and urinary tract infection signs and symptoms refractory to antibiotic therapy. He was eventually found to have a left kidney mass detected at the District hospital by abdominal ultrasound performed to evaluate a flank mass that was felt by his mother. He was then referred to our unit for a suspicion of Wilms' tumor which finally turned out  to be a left kidney Xanthogranulomatous pyelonephritis. He underwent a successful left nephrectomy and was discharged from hospital in a stable clinical condition and remains asymptomatic at the time of submission of this case report. CONCLUSION: This case report underscores the need for clinicians attending a febrile child with a renal mass that can be confused with common pediatric renal malignancies such as Wilms' tumor to broaden their differential diagnosis. The case also underlines the significance of individualized patient evaluation because this patient would have otherwise received preoperative chemotherapy under the International Society of Pediatric Oncology (SIOP) guidelines if the diagnosis of Wilms tumor was not ruled out.