A cyst is a closed sac structure that develops in the body, typically filled with a fluid, air, or semi-solid material. These sacs can form in various tissues, and when they occur near the hip joint, they often present as a noticeable lump or cause internal joint pain. Most cysts found in the hip area are benign, meaning they are non-cancerous and not immediately life-threatening. However, any new or growing lump near a joint requires a medical evaluation to determine its exact nature. A professional diagnosis is necessary to distinguish a harmless fluid collection from a potentially more serious solid mass.
Types of Benign Hip Cysts
Cysts around the hip are frequently related to the joint itself or the soft tissues surrounding it, and they are usually slow-growing. One common type is the synovial cyst, which often forms near the hip joint capsule as a result of increased fluid pressure within the joint. This increased pressure, often linked to underlying conditions like osteoarthritis or a labral tear, pushes the lubricating synovial fluid out to create a sac-like structure. Synovial cysts may enlarge and cause pain or compression on nearby nerves or vessels when they become distended.
Another category is the subchondral cyst, a fluid-filled cavity that forms within the bone just beneath the cartilage surface. These cysts are a common feature of degenerative joint disease, like osteoarthritis, where cracks in the joint cartilage allow fluid to seep into the underlying bone.
Epidermal inclusion cysts are skin-related, originating from the implantation of surface skin cells into the dermis. This type is filled with keratin and presents as a firm lump just beneath the skin, rarely causing deep hip pain unless it becomes infected. It is also common for people to mistake an inflamed bursa, a fluid-filled sac that reduces friction near a joint, for a cyst; this condition, known as bursitis, can present with similar tenderness and swelling.
Signs That Indicate a Serious Concern
While most hip cysts are harmless, certain signs should prompt immediate medical attention as they may suggest a serious underlying problem, such as an infection or a malignant tumor. A lump that exhibits rapid growth over a short period is a significant red flag, contrasting with the typically slow progression of benign cysts. Intense, unrelenting, or rapidly worsening pain that is not relieved by rest or over-the-counter medication also suggests a more aggressive process.
Changes in the skin overlying the lump, such as pronounced redness, heat, or swelling, can indicate an infection within the cyst or surrounding tissue. An infection may also be accompanied by systemic symptoms, including a fever or chills. Furthermore, any cyst or mass that causes a sudden loss of mobility or function, or is associated with new neurological symptoms like numbness, tingling, or weakness, warrants urgent evaluation. These symptoms can signal that the mass is compressing a major nerve.
Medical Procedures for Diagnosis
A physician will begin the diagnostic process with a thorough physical examination, assessing the size, mobility, and tenderness of the lump, and evaluating the hip’s range of motion. Following the physical exam, imaging techniques are necessary to determine the exact composition and location of the mass.
Ultrasound is often the initial imaging tool of choice because it is quick, non-invasive, and effective at confirming whether the mass is a simple, fluid-filled cyst or a solid structure. For a more detailed assessment, a Magnetic Resonance Imaging (MRI) scan is considered the standard, providing high-resolution images of soft tissues, cartilage, and bone. The MRI helps differentiate between a synovial cyst, a subchondral cyst, and other potential masses, and it can reveal associated joint damage, such as a labral tear.
Computed Tomography (CT) scans are used to provide high-resolution views of the bone structure, which is particularly helpful for evaluating cysts that have formed within the bone. If imaging suggests the mass is solid, or if there is any suspicion of a tumor, a definitive biopsy may be required, which involves taking a small tissue sample for laboratory analysis.
Treatment Options Based on Severity
The management of a hip cyst is directly determined by its diagnosis, size, and the severity of the symptoms it causes. For many benign, small, and asymptomatic cysts, the recommended approach is simply observation, often called the “wait-and-see” strategy, with periodic imaging to monitor for growth or changes. Conservative measures like rest, anti-inflammatory medications, and physical therapy are the first line of treatment for mildly symptomatic cysts, particularly those associated with underlying conditions like osteoarthritis.
If a cyst is causing significant pain or compressing a nerve, a procedure called aspiration may be performed, involving the use of a needle, guided by ultrasound or fluoroscopy, to drain the fluid and reduce the pressure. Aspiration is frequently effective for synovial or paralabral cysts, but recurrence is possible since the underlying cause may not have been addressed.
Surgical excision is typically reserved for cysts that are severely symptomatic, recur after aspiration, are very large, or are causing neurological compromise. If the mass is confirmed to be a malignant or aggressive tumor, surgical removal will be performed alongside other treatments, such as radiation or chemotherapy.