What Is Spindle Cell Lipoma

Introduction

What is spindle cell lipoma?

Spindle cell lipoma, abbreviated as SCL, is an rare variety of tumour primarily located within the fatty tissues beneath the skin, commonly appearing in the neck and shoulder regions.

These growths, reassuringly, are classified as benign, signifying they are non-cancerous.¹ However, SCL has the potential for progression if left unattended, potentially leading to complications such as nerve compression akin to a pinched nerve.

Of note is the typical demographic affected by SCL. It most frequently arises within the age bracket of 50 to 70, with a greater prevalence among the population of those assigned male at birth (AMAB), accounting for approximately 90% of SCL cases.²

Why awareness matters

Understanding SCL is essential, as knowledge is a potent tool for safeguarding your health. Early detection can significantly impact the course of the condition, making timely recognition very important. To assist you, we have provided a practical checklist to help you identify possible warning signs:

1. Look for a singular lump located on your neck, upper back, or shoulders
2. Gently assess the lump by applying light pressure; if it moves, this is a positive sign
3. An SCL should be painless
4. The growth rate of SCL should be slow

However, it is crucial to seek professional evaluation for any growth, lump, or bump. An official diagnosis by a healthcare provider is a vital step, as SCL can sometimes bear a resemblance to more serious conditions like liposarcoma and other cancers.³ Ensuring a clear diagnosis allows for precise treatment decisions, highlighting the importance of timely healthcare assessments.

Causes and risk factors

As we mentioned before, spindle cell lipoma is most prevalent in AMABs aged 50 to 70, but did you know there are other risk factors that increase the likelihood of SCL? 

Researchers are yet to fully identify the exact cause of SCL, however, some key trends among patients has been noted.

Genetics

Some studies have suggested a genetic predisposition to SCL, meaning that spindle cell lipoma can run in families. It's important to understand that the genetics of SCL are likely to be complex and influenced by multiple genes and environmental factors, so a family member developing spindle cell lipoma rarely means you or other family members will. 

Scientific research into the genetics of SCL is ongoing, and some studies have attempted to identify specific genetic markers or mutations associated with this condition.⁴ If there is a strong family history of SCL or other related conditions, individuals may consider genetic counselling. Genetic counsellors can assess family history and provide information on the potential genetic risk factors associated with SCL.

Lifestyle and injury risk factors

Several risk factors have been associated with the development of SCL, and highlight the importance of a healthy, balanced lifestyle. Obesity, the overconsumption of alcohol, glucose intolerance, and liver disease have all been identified as possible attributors to lipoma growth. 

Additionally, some research supports a link between trauma or injury of SCL prone areas (the neck, back and shoulders) and the production of SCL.⁵

Diagnostic approaches

The diagnosis of spindle cell lipoma typically involves a combination of diagnostic approaches, including imaging studies (scans), biopsies, and histological examinations. These methods help healthcare professionals accurately identify and characterise SCL, differentiating it from other growths and allowing for the best course of treatment moving forward. 

Overall there are many methods that can be used to identify SCL, and oftentimes these methods are performed in conjunction with one another to better understand the SCL, its contents and positioning on the body. This includes imaging studies (such as ultrasounds, MRIs and CT scans) and biopsy and histoligcal examinations.

Imaging studies

Ultrasound imaging is often the initial step in evaluating a suspected SCL. It can help visualise the location, size, and density of the growth. SCL typically appears as a well-defined, encapsulated mass within the fatty tissues.²

SCL typically contain between 25-75% fat, however, a significant number of SCL are dubbed “low-fat” or “fat-free” which can give them an appearance of aggressive cancers.² MRI scans are used for the best detection of non-fatty tissues, and thus, differentiation from other tumours.

Computerised tomography (CT) scans can also be used to assess the location and density of the mass, and can give an insight into both the fatty and non-fatty tissues making up the tumour.²

Biopsy and histological examination

Fine needle aspiration (FNA) is a very effective method to determine the initial characteristics of an SCL. This is achieved through a small sample of tissue being extracted from the suspected SCL using a thin needle and sample then being examined under a microscope. The types of cells are identified, paying close attention to the spindle cells and their nuclei.⁶

After the biopsy, the collected tissue sample undergoes histological examination by a pathologist. This detailed analysis allows the pathologist to examine the tissue's cellular composition and structural characteristics. The presence of spindle cells, which are elongated cells with a distinct appearance, is a key feature that helps distinguish SCL from other soft tissue tumours.⁷

Treatment options

The treatment options for spindle cell lipoma will depend on various factors, including the size and location of the tumour, the patient's overall health, and whether the tumour is causing any symptoms. We will now explain the most common treatment options, and when they might be used.

Observation and monitoring

Spindle cell lipoma is usually small (less than 2.5 cm in diameter) and does not present any symptoms in the patient, and as such, a “watch and wait” approach may be taken.⁸ The SCL will be regularly monitored via the imaging studies outlined prior to ensure that it remains stable, does not grow, and remains asymptomatic. If a significant change does arise, or the SCL starts to cause the patient discomfort, another treatment method may be introduced to remove the growth.

Surgical excision

If the spindle cell lipoma is large, growing, causing the patient discomfort, or the patient wants it removed for cosmetic reasons, surgical excision will likely be recommended, as is currently the most common and effective treatment for the removal of SCL. This procedure involves the removal of the entire tumour alongside a small amount of normal tissue encapsulating it to ensure its complete removal. The surgery will take place either under local anaesthesia (an numbing injection at the site of surgery) or general anaesthesia (sleep inducing medicine) depending on the tumours size and location on the body. Surgery is generally considered curative, with the chances of the SCL coming back being low.

Liposuction

Another method, albeit a rarely used one, for removing spindle cell lipoma is liposuction. We all know liposuction in the context of cosmetic surgery but it can also be used to remove lipomas that are primarily composed of adipose (fatty) tissue. This can be beneficial to the patient as small SCL can be removed with minimal scarring, however, this treatment is very costly and complete lipoma removal is not possible.⁹

Recurrence management

Thankfully, there is a very small chance of recurrence of SCL after treatment. If a recurrence occurs, it is often managed by further surgical excision. Close follow-up and monitoring are essential to detect any recurrence early. One of the most common causes of recurrence is due to some tumour cells remaining after surgery, which will go on to develop into another full SCL. In some cases, if the recurrence is associated with symptoms or signs of aggressive behaviour, further evaluation and possible additional treatment may be necessary.

Prognosis and complications

As spindle cell lipoma is considered a benign tumour, it has no potential to metastasize (spread to other parts of the body). Additionally SCL does not pose a life-threatening risk in the vast majority of cases.

Whilst most SCL present as asymptomatic, some complications may arise due to its size and location. Nerve compression, commonly referred to as a “pinched nerve”, may occur when a tumour grows too close to a nerve, leading to pain, a tingling sensation in the limbs, or weakness in affected areas. If a SCL grows near or in muscles or joints it may cause functional impairment of the area, making mobility difficult. Additionally, depending on where the SCL grows, it may cause visible lumps and be a cosmetic concern for the patient.

FAQs

What is the difference between a spindle cell lipoma and a lipoma?

Spindle cell lipomas are a specific subtype of lipoma. They are composed of fat cells but have a significant component of spindle-shaped (elongated) cells. Additionally, SCL can be larger than common lipomas.

What are spindle cell lipoma characteristics?

Spindle cell lipomas are movable, small lumps located around the neck, shoulders and back. They are firmer than normal lipomas due to being composed of a mixture of mature fat cells (adipocytes) and spindle-shaped cells. They are asymptomatic, benign and easily removable with surgery.

Do liposarcomas have spindle cells?

Liposarcomas are malignant tumours predominantly made up of fat cells that can vary in their composition. The presence or absence of spindle cells will depend on the specific subtype of liposarcoma.

Summary

Spindle Cell Lipoma, or SCL, is a relatively rare, benign tumour that typically occurs in the fatty tissues beneath the skin, most commonly in the neck and shoulder areas. Although benign, SCL can progress and lead to complications like nerve compression or functional impairment. It is predominantly found in individuals aged 50 to 70, with a higher incidence in males, constituting about 90% of cases.

Early detection can allow for observation by healthcare practitioners, and subsequent treatment as soon as is necessary. Watch for a single, mobile, lump in the neck, upper back, or shoulders. SCLs are typically painless, and their growth is slow. However, consulting a healthcare provider for an official diagnosis is crucial because SCL can sometimes be mistaken for more serious conditions like liposarcoma.

Research into SCL's exact causes continues, but some risk factors have been identified, including genetics and lifestyle factors like obesity, alcohol abuse and trauma.

The diagnosis of SCL involves various methods, such as imaging studies, biopsy, and histological examinations. Effective treatment options include observation, surgical excision, liposuction, and recurrence management. Surgical excision is by far the most common method of treatment for a large SCL, and depending on the size and position, will be performed under local or general anaesthesia. Thankfully, after complete removal, the chances of an SCL recurring is low. 

The prognosis for SCL is generally positive, as it's non-metastatic and not life-threatening. Nevertheless, complications can arise due to the tumour's size and location, at which point the removal of the SCL is recommended.