Tuberculosis of the Tibial Plateau Mimicking a Giant Cell Tumor: A Case Report.

Tuberculous osteomyelitis is infrequent and occurs most often in the femur, the tibia, and the small bonne of hands and feet. Herein, we report a 39-year-old female who presented with chronic pain and motion range reduction of the left knee joint for two years. A knee radiograph revealed a geographic lytic lesion of the epiphyseal and diaphyseal region of the tibia mimicking giant cell tumor (GCT). A minimally invasive biopsy of the lytic lesion was performed, and pathological assessment revealed granulomatous inflammation made of numerous caseating necrotizing epithelioid and giant cells granulomas, diagnostic of tibial plateau tuberculosis. This case underscores the importance of taking tuberculosis into consideration in lesions mimicking GCTs in the tibial plateau, especially in endemic regions.

Late Diagnosis of Primary Hyperoxaluria in an Adult Patient With End-Stage Renal Disease and Bicytopenia.

Primary hyperoxaluria (PH) is a rare genetic condition that disrupts the normal process of glyoxylate metabolism, resulting in an overproduction of oxalate. This excessive oxalate production leads to the accumulation of calcium oxalate (known as oxalosis) throughout various organs in the body. The urinary tract, specifically the renal parenchyma, is the first location where the deposition of calcium oxalate begins in PH. These deposits are responsible for nephrocalcinosis and tubule­interstitial nephritis which leads to end­stage renal failure. This is then followed by the accumulation of oxalate in other organs including the bone marrow. Herein, we report the case of a 22-year-old male patient who presented with bicytopenia; he had a history of end-stage renal disease preceded by recurrent urolithiasis and nephrolithiasis episodes since the age of 3 years. A bone marrow biopsy was performed for evaluation of the bicytopenia which led to the diagnosis of PH.

Acute pyelonephritis revealing a rare renal collision tumor of papillary and chromophobe cell carcinoma with sarcomatoid features.

A 59-year-old male patient was admitted to the emergency room with febrile right flank pain. The computed tomography scan and the magnetic resonance imaging had objectified lesion image occupying the upper half of the right kidney, measuring 82 mm, suggesting an infectious origin without excluding the infected tumor. He was put under antibiotics. A percutaneous biopsy revealed renal cell carcinoma with suppurative tumor necrosis. He underwent a right radical nephrectomy. The histopathological study revealed a collision tumor of papillary, chromophobe renal cell carcinoma and sarcomatoid dedifferentiation. It is the second case reported in English literature to date.