Abstract

Unilateral leg swelling poses a diagnostic challenge with a myriad of potential differential diagnosis, including deep vein thrombosis (DVT), Baker's cyst, and cellulitis. As some of these causes can be benign and easily treatable, other causes may be more severe and even life threatening. This article highlights the critical need for healthcare professionals to expand their differential diagnosis when common causes have been excluded, recognizing that some rare etiologies may signify severe underlying conditions. We present the case of a 55-year-old female with a two-month history of right leg swelling, initially attributed to erysipelas due to negative DVT findings. Upon closer examination, an abdomino-pelvic CT scan revealed diffuse peritoneal carcinomatosis, obstructing the right external iliac vein and elucidating the unilateral lower limb edema. This case focuses the importance of considering atypical causes, especially in patients with a history of cancer, and the potential life-threatening nature of rare etiologies. The article emphasizes the significance of a multidisciplinary approach, comprehensive laboratory assessments, and advanced imaging techniques in achieving accurate and timely diagnoses, ultimately guiding effective patient management.