Key Difference – Nodule vs Cyst
The key difference between nodule and cyst is that the nodules contain solid materials while the cysts contain fluid. Skin lesions are a common manifestation of many benign and sinister pathological processes taking place inside the human body. Nodules and cysts are two such skin lesions that appear in different disease conditions. Although commonly arising on the skin, it is also possible for these lesions to occur within the internal organs of the body. A nodule is a solid mass in the skin, usually greater than 0.5cm in diameter, both width and depth, and it can appear as elevated from the skin or palpated. Whereas, cysts are nodular lesions containing fluid.
CONTENTS
1. Overview and Key Difference
2. What is a Nodule
3. What is a Cyst
4. Similarities Between Nodule and Cyst
5. Side by Side Comparison – Nodule vs Cyst in Tabular Form
6. Summary
What is a Nodule?
A nodule is a solid mass in the skin, usually greater than 0.5cm in diameter, both width and depth which can appear as elevated from the skin or palpated.
Conditions that can give rise to nodular skin lesions include,
- Repair mechanisms that are involved in the heal of injuries to body organs can give rise to nodular lesions such as keloid scars.
- Nodules can develop even within the internal body organs. In inflammatory conditions such as rheumatoid arthritis, patients can get pulmonary nodules. Granulomas occurring in certain diseases such as TB are also a type of nodules.
Figure 01: Subcutaneous rheumatoid nodules
- Malignancies can also give rise to nodules.
- Thyroid nodules are one of the commonest variety of nodular lesions and are due to a spectrum of pathological conditions including iodine deficiency and thyroiditis.
What is a Cyst?
Cysts are nodular lesions containing fluid. Different types of cysts commonly encountered during clinical practice are,
- Sebaceous cysts – these have a bluish discoloration on the overlying skin along with a punctum. Surgical excision of them is necessary in order to prevent them from getting an infection.
- Dermoid cysts
- Cysts in the internal organs such as thyroid gland, ovaries, and kidney
- Painful Bartholin cysts in Bartholin glands of females
Figure 02: Ultrasound Appearance of the Renal Cysts
What are the Similarities Between Nodule and Cyst?
- Nodule and cyst are more than 0.5cm in diameter.
- Moreover, both have margins that are elevated from the skin level and are palpable.
What is the Difference Between Nodule and Cyst?
Nodules are solid masses in the skin that can appear to be elevated from the skin or palpated whereas cysts are nodular lesions containing fluid. Therefore, the key difference between nodule and cyst is that the nodules contain solid materials while the cysts contain fluids.
The table below further summarizes this difference between nodule and cyst.
Summary – Nodule vs Cyst
A nodule is a solid mass in the skin, usually greater than 0.5cm in diameter, both width and depth. It can appear to be elevated from the skin or palpated. Cysts also are nodular lesions containing fluid. Accordingly, the major difference between nodule and cyst is that nodules are filled with solid materials whereas the liquids are filled with fluids.
Reference:
Image Courtesy:
1. “Subcutaneous rheumatic nodules on the ears and knee Wellcome L0062023” By Welcome Gallery (CC BY 4.0) via Commons Wikimedia
2. “Renal cyst ultrasound 110316115548 1208010” By © Nevit Dilmen (CC BY-SA 3.0) via Commons Wikimedia
