Lump on the Back of the Neck Hairline

In this article, we will take a close look at the various conditions that could result in a lump on the back of the neck at the hairline. We will discuss benign cysts, infections, cancers, and other serious issues, emphasising the importance of consulting a healthcare professional for an accurate diagnosis and early treatment.

Author - Jakub Hantabal

Postgraduate student of Precision Cancer Medicine at the University of Oxford, and a data scientist.

Jakub used MediSearch to find sources for this blog.

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Lump on the Back of the Neck Hairline: Possible Causes

A lump on the neck can be a cause for concern. However, fortunately, evidence suggests that most lumps on the neck are harmless, and can be resolved with cosmetic surgery if needed. In this blog, we review the conditions possibly manifesting as a lump on the neck at the hairline, as well as the diagnostic and therapeutic pathways.

Sebaceous cyst

A sebaceous cyst is a common type of cyst (an encapsulated formation of pus or foreign material) that is filled with oily material called sebum. Sebum is produced by glands that moisturise the skin [1]. These cysts are non-cancerous and usually do not cause symptoms except for the presence of the lump.

Epidermal inclusion cysts

These are cysts similar to sebaceous cysts, however they contain different material to sebum. Both sebaceous cysts and epidermal inclusion cysts are very similar in appearance, as well as treatment.

Ingrown hairs

Ingrown hair forms when a hair grows into the skin rather than out. This results in a pimple-like bump forming around the hair follicle. These formations are common in areas where hair is regularly removed, such as the hairline at the back of the neck [1].

Boils

Boils (also referred to as furuncles) are pus-filled bumps that form under the skin due to bacteria entering the hair follicles. These commonly form in areas with hair that are exposed to sweat and friction, making the hairline at the back of the neck very vulnerable [1].

Lipomas

Lipomas are lumps of fat that appear between the skin and muscle underneath. These are non-cancerous growths that are soft to the touch (with a dough-like consistency), and move under the skin when pressure is applied through the skin [1].

Acne keloidalis nuchae

Acne keloidalis nuchae is an imflammation of the hair follicle that presents as small bumps that specifically presents on the back of the scalp at the hairline. It is very common in young black males, and begins as an acne-like breakout that leads to the formation of bumps made of scar tissue in the area [1].

Swollen lymph nodes

Swollen posterior cervical lymph nodes, located near the back of the neck, can also present as a lump that is visible and palpable. The most common cause of swollen lymph nodes is a viral infection, such as a cold or the flu, however, this may be a sign of more serious infections such as HIV or even cancer [1].

Can a neck lump be cancer?

Several types of cancer can manifest with a lump on the neck. These include:

Lymphomas - a type of cancer that originates from the cells of the lymphatic system, which is a component of the immune system. Lymphomas are a very diverse group of cancers, of which some present as lumps on the body, particularly on the neck given the close proximity to the lymph nodes in the back. Lymphomas can be very aggressive, and require a rapid therapeutical interventions [2].
Thyroid cancers - these originate in the thyroid gland, which is an organ in the front of the neck which produces hormones that regulate the body's metabolism. This cancer is often observed in middle-aged individuals, and is more common in females. While thyroid cancer typically presents as a lump in the front of the neck on or around the gland itself, additional lumps can develop in the back of the neck as well [3].
Head and neck cancers - a collective term used to describe cancers of the mouth, throat, and salivary glands [2]. Squamous cell carcinoma is a very common type of head and neck cancer. Some of these can present with a lump on the neck, which is fast-growing.
Leukaemias - cancers of blood-forming tissues. Some leukaemias present with a lump on the neck, particularly around the lymph nodes [4].
Metastases of other cancers elsewhere - metastasis is an occurrence where cancer cells detach from the primary tumour, travels around the body in the bloodstream and starts growing another tumour - the metastasis. Most cancers can metastasise to the neck and form a lump, including lung, breast, and skin cancers, such as basal cell carcinoma, squamous cell carcinoma, and melanoma [2].

Neck Lump: Diagnostic process

The diagnostic pathway for a lump on the neck involves several steps.

Firstly, a physical examination is the most important part of the diagnostic process. The doctor will examine the lump visually for redness or presence of pus visible through the skin, as well as by touch (palpation) for firmness, temperature (hot may be a sign of infection) and mobility.

Importantly, the doctor will collect history and ask about how the lump appeared and whether it has grown recently [2].

If the lump is deemed to be at a risk of malignancy (potentially cancerous), imaging studies such as X-ray, neck computed tomography (CT) or magnetic resonance imaging (MRI) with contrast may be indicated [5].

In some cases, a fine-needle aspiration biopsy may be performed. This is an in-office procedure where the tissue is numbed with local anaesthesia and a needle is inserted into the mass. Cells or material from the lesion are then aspirated and examined under the microscope [5].

Treatment of a Neck Lump at the Hairline

The treatment choice for a lump on the back of the neck relies on the underlying cause.

Lumps that are acne, abscesses or ingrown hairs are often removed for cosmetic reasons. These are usually drained of fluid and the capsule that holds the contents of the cyst is removed. The wound is then closed by stitches. This is a fast and safe procedure done in office, performed under local anaesthesia [1, 6]. Lipomas are removed this way as well. Antibiotics may be administered to manage any possible infections.

If the lump is due to cancer, the focus is on removal of the lesion and subsequent management of the patient. The lump is removed with margins (pieces of healthy tissue removed to ensure that all potentially cancerous cells are removed). Additional options include radiation to the tumour site, however this needs to be planned carefully and meticulously to minimise damage to the surrounding structures in the neck such as the vocal chords, spinal cord and the thyroid gland. If the lump is a metastasis, systemic cytotoxic chemotherapy is needed [2, 6].