Acute compartment syndrome due to skeletal muscle metastases from poorly differentiated upper gastrointestinal adenocarcinoma: a case report.

Background: Acute compartment syndrome (ACS) is characterized by increased pressure within the fascial network of any muscle, leading to impaired circulation and potential myonecrosis. Very rarely, soft tissue infiltration by metastatic disease can cause localized swelling that increases intercompartmental pressures. We report an unusual case of invasive, poorly differentiated upper gastrointestinal adenocarcinoma presented by acute compartment syndrome of the lower extremity and subsequent acute kidney injury (AKI) caused by myonecrosis-induced cast nephropathy.