Abstract
Background
Bladder cancer is one of the more common urologic cancers that stems from the lining of the bladder. Muscle-invasive forms of bladder cancer are less common but considered more aggressive, typically leading to metastases across the body. Bone is the second most common site of metastasis following lymph nodes in the setting of bladder cancer. Despite this, metastasis to the tibia is uncommon. Detection and thorough management of this pathology is incredibly important.
Methods
We present a single case study of a 76-year-old male who presented with lower extremity pain, erythema and ambulatory dysfunction who was found to have a pathologic distal tibial fracture secondary to metastasis from a primary bladder cancer.
Discussion
Early recognition and proper treatment of bone metastasis in the lower extremity is vital. Skeletally-related events such as pathologic fracture, as we illustrate in our case, as well as continued pain and loss of function are important considerations to be aware of. We provide a review of literature, current concepts in management and important things to consider for the foot and ankle surgeon when managing patients with this condition.
Introduction
Bladder cancer is a relatively common urologic cancer that stems from the lining of the bladder. This form of cancer is the ninth most diagnosed cancer globally, and ranks thirteenth in mortality rate with an increased incidence in males. Of those cases diagnosed, 75% are non-muscle invasive while 25% are muscle-invasive and carry risk of metastasis. Cognizance of the associated risks for morbidity and mortality, especially with regards to the osseous components of the lower extremity, is important. Cases of bladder carcinoma with bone metastases are associated with decreased quality of life and survival, with an heightened risk of skeletally-related events including pathologic fracture, spinal cord compression and hypercalcemia. , In a study by Shinagare et al., of 392 patients diagnosed with muscle-invasive bladder cancer, bone was noted to be the second most common site of metastasis at 47%, following lymph nodes. Bone is the most common site for distal metastasis and is found in 30–40% of metastatic bladder cancer cases. The one-year survival rate of patients with bladder cancer has been reported as 84%, however, in those with bone metastases the survival rate was substantially reduced to 21% with a median survival time of 4 months.
Although there are currently no formal guidelines for screening of bone metastases in the setting of bladder cancer, early detection is vital for preventing further skeletal complications. Identification of possible bone involvement relies primarily on sign and symptom recognition and obtaining PET-CT and bone scans. The most common site of bone metastasis is the pelvis, followed by the ribs, skull, femur and proximal humerus. Metastasis to the tibia has been infrequently published in the literature. There are select case reports in the literature that describe a common presentation of rapidly progressing leg pain, sometimes accompanied by loss of function, deformity, fracture or skin manifestations such as edema and erythema. Although atypical, one must keep a high suspicion of potential tibial bone involvement as a secondary site from primary bladder cancer if a patient presents with this constellation of symptoms. In the following case report, we discuss the rare diagnosis of distal tibial metastasis from primary muscle-invasive bladder cancer from the musculoskeletal perspective, and emphasize pearls for early recognition and prompt management.
Case report
The patient was a 76-year-old male with a past medical history of hyperlipidemia, gastroesophageal reflux disorder, hypertension, chronic kidney disease, bladder cancer status post radical cystoprostatectomy, ileal conduit with bowel anastomosis with right inguinal hernia repair presented to the emergency department with a primary complaint of left lower leg pain and erythema. The patient was initially diagnosed with bladder cancer after presenting with a history of gross hematuria and 20-pound weight loss. Ultrasound revealed a bladder mass, and CT imaging confirmed a bladder tumor with right hydronephrosis. Patient subsequently underwent transurethral resection of the bladder tumor (TURBT) which was noted to be 6 cm on resection with invasion into muscularis propria. He was then placed on a 1-year course of Nivolumab immunotherapy. He subsequently presented 7 weeks following initiation of immunotherapy with left lower leg pain. On an outpatient basis, his oncologist treated the patient with Keflex and a Prednisone taper for presumed pre-tibial cellulitis. He began to develop ambulatory dysfunction which prompted his presentation to the emergency department, at which time our service was consulted. Plain radiographs of the left tibia were obtained which showed multifocal destructive lytic cortical lesions throughout the distal tibial diaphysis with a non-displaced pathologic fracture through the medial distal tibia ( Fig. 1 ). This was concerning for osteomyelitis versus lytic lesion associated with malignancy. The patient was admitted for further workup. He did receive a single dose of IV vancomycin and cefepime in the emergency department, then infectious disease recommended monitoring his condition off of antibiotics as he was hemodynamically stable with normal vitals and relevant lab work.
Ankle radiographs showing multifocal destructive lytic cortical lesions throughout the distal tibial diaphysis with a non-displaced associated pathologic fracture.
An MRI of left lower extremity was obtained which showed bone marrow infiltration with low T1 signal and high STIR signal in the left tibia extending from mid tibial shaft through tibial metaphysis, with extensive cortical erosion circumferentially around the distal tibia ( Fig. 2 ). The MRI also showed a soft tissue extension measuring up to 13.5 mm in thickness and 11.1 mm in length around in the mid tibia, possibly representing neoplasm ( Fig. 3 ). A bone scan was obtained which showed uptake to the mid and lower tibia most concerning for an aggressive process ( Fig. 4 ). Interventional Radiology performed a CT-guided deep bone core biopsy of the distal tibia ( Fig. 5 ). The pathology report was finalized which confirmed metastatic carcinoma to the tibia, most consistent with urothelial origin. During his hospital course he also developed nausea and vomiting. A CT scan confirmed multiple hepatic metastases, and an EGD was performed which showed duodenal malignancy as well. At this point the patient was offered surgical intervention for metastasis tumor resection as well as open reduction with internal fixation of the pathologic tibial fracture, however he deferred further intervention. He had persistently low oral intake with worsening fatigue and weakness, therefore palliative care was consulted. The patient was soon transitioned to hospice care with comfort measures only, and subsequently passed away a couple of days later.
