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Indications nodule sous-cutané cancéreux.

How can you determine if a nodule under the skin is cancerous?

A subcutaneous nodule is an abnormal mass located beneath the skin. Generally benign, it can become cancerous. What are the signs? Let's discover together how to identify a potentially malignant nodule.

Published January 22, 2024, by Kahina, Scientific Editor — 5 min read

Nodules: some generalities.

A nodule is an abnormal growth of tissue, which can form just beneath the skin but also within deeper skin tissues or internal organs. It resembles a lump typically visible to the naked eye and palpable to touch. The nodule can be round or irregular in shape, hard or soft, with regular or irregular contours, be mobile or fixed, attached to the muscle or not. Areas where nodules can be observed include, among others, the armpits, groin, and the head and neck region.

  • Cysts : these round lumps, often filled with fluid and pus, can vary in size from a few millimetres to a few centimetres. There are different types of cysts:

    • Les kystes épidermoïdes qui se développent dans l'épiderme. Ils sont généralement congénitaux, c'est-à-dire présents dès la naissance, mais peuvent aussi être acquis après un accident.

    • Les kystes sébacés qui sont caractérisés par une accumulation de sébum sous la peau.

    • Les kystes ganglionnaires qui peuvent se trouver vers les articulations, comme le poignet ou les doigts.

    • Les kystes liés à l'acné qui sont des boutons typiques de l'acné nodulaire ou nodulo-kystique, et se caractérisent par des lésions inflammatoires allant vers l'abcédation, c'est-à-dire la rupture et la formation de cicatrices.

  • Lipomas: these refer to benign fatty tumours. They are typically a firm or soft nodule with a normal smooth surface, a few centimetres in diameter. Most are asymptomatic and are characterised by a fatty deposit under the skin. While the causes are not yet well understood, the origin could be genetic.

  • Histiocytoma (dermatofibroma): This is a lesion typically found on the lower limbs of adult women in particular. It presents as a rounded nodule of a few millimetres with a brownish surface. It is firm and painless. This lesion generally develops following a local trauma, such as an insect bite.

  • Warts : harmless and often not requiring treatment, warts are irregular surface growths caused by the human papillomavirus, following direct contact with an infected person or with the environment.

  • Skin tags: These are small brown papules that appear in skin folds. They can occur as a result of irritation caused by skin friction.

Benign or cancerous subcutaneous nodules: how to tell the difference?

Most subcutaneous nodules are benign. However, there are instances when they can become cancerous. Here is a comparison chart of possible symptoms to better guide you.

Characteristics of Benign NodulesCharacteristics of concerning nodules (potentially cancerous)
Slow development and rapid disappearanceRapid Development and Persistence
A rather soft nodule, moving beneath the skin with regular edgesFirm nodule, slightly mobile (or fixed) with irregular edges
No specific skin changes or painSkin changes such as the onset of redness or pain
No physiological symptomsNight sweats and itching accompanying the nodule
/Location within a beauty spot

Worrisome nodules can hide malignant tumours, such as basal cell carcinomas, squamous cell carcinomas or malignant melanomas of the skin. At the slightest doubt, do not hesitate to consult a dermatologist if you notice the presence of a subcutaneous lump on the skin. In this scenario, it is preferable to establish an accurate diagnosis.

How is it diagnosed?

Basic tests such as the "complete blood count" (CBC) and the "erythrocyte sedimentation rate" (ESR) are conducted in order to count and classify the various components of the blood and measure the degree of inflammation.

Subsequently, a urine analysis is necessary if the presence of inflammatory skin masses is suspected. Ultrasound can enhance the diagnosis for significant lesions. An excision biopsy may also be considered in order to analyse and determine the cause of the nodule.

How is it treated?

Following the diagnosis of a malignant tumour, radiotherapy or chemotherapy will be considered, depending on the case. Excision as part of primary care is not recommended.

Non-pathological subcutaneous nodules do not require treatment, and in some cases, may dissolve over time. However, depending on the patient's request, they can be removed by endoscopy, for aesthetic purposes for example.


  • SAURAT J.H., LIPSKER D., THOMAS L., BORRADORI L. and LACHAPELLE J.M. Dermatologie et infections sexuellement transmissibles. Elsevier Masson (2017).

  • TIDY C. Lipoma. Patient (2021).

  • TIDY C. Skin and subcutaneous nodules. Patient (2021).

  • HAZELL T. Skin tags. Patient (2022).

  • WILLACY H. Viral warts. Patient (2022).


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