Tubercular Popliteal Cyst as a Primary Presentation in an Adult: A Case Report and Review of the Literature.

Abstract

A popliteal cyst is the most common cystic lesion around the knee and is also known as a popliteal synovial cyst or a Baker cyst1,2. A popliteal synovial cyst results from the collection of synovial joint fluid through a synovial defect in the posterior capsule of the knee joint. It was first described by Adams in 1840, and subsequently popularized by Dr. William Morrant Baker in 18771,2. These cystic swellings in the popliteal region have been evaluated with anatomical cadaveric studies and magnetic resonance imaging (MRI)3, which has helped us to understand the underlying pathology. Although noninfectious conditions like degenerative joint disease, internal derangements of the knee, and inflammatory conditions of the knee are commonly associated with a Baker cyst, infective arthritis can also present as a popliteal cyst3-6. However, an infected popliteal cyst without knee joint involvement is a rare presentation. This case report describes a patient with a tubercular popliteal cyst. The patient was informed that data concerning the case would be submitted for publication, and he provided consent. A twenty-two-year-old man presented with pain of two weeks’ duration in the upper leg. The pain was dull aching and continuous, regardless of the nature of the activity. He had no history of trauma, no constitutional symptoms, and no prior contact with a patient with active tuberculosis. The patient was well nourished and of moderate build. Local examination of the right leg revealed edema over the anteromedial aspect of the upper leg, with diffuse fullness over the proximal aspect of the calf. No warmth of the area was detected but there was induration. Deep palpation showed no underlying focal or diffuse osseous tenderness, thickening, or irregularity. The circumference of the calf was increased compared with …