What are the other Names for this Condition? (Also known as/Synonyms)

• Solid Glomus Tumors
• Solitary Glomus Tumors

What are Glomus Tumors? (Definition/Background Information)

• Glomus Tumors are a group of uncommon tumors caused by the proliferation of glomus cells, which are found in the glomus body. The glomus body is a small organ found in large numbers all over the body. It controls and helps regulate the body temperature and blood flow. The origin of the Glomus Tumor is from these glomus bodies
• Based upon the histology features under the microscope, Glomus Tumors can be classified as:
  • Benign Glomus Tumor: It is the most common type, and most tumors occur on or just beneath the skin (superficial location)
  • Atypical Glomus Tumor: This type presents features that may be initially benign, but with time, turn malignant
  • Malignant Glomus Tumor: It is an extremely rare form of glomus tumor and are mostly found in the deep tissues of the body
• Superficial tumors are usually painful and the development of pain is the reason why many individuals seek a healthcare consultation. These tumors are mostly benign. Deep-seated tumors are diagnosed incidentally as a mass, when investigations are on for other medical conditions. Such tumors are usually atypical or malignant
• The exact cause of tumor formation is not known, though several genetic mutations have been identified. Most commonly, young adults are affected by Glomus Tumors
• Complete surgical excision and removal of the tumor is the treatment measure that is undertaken. Medical therapy or chemotherapy is not considered effective for malignant Glomus Tumors. Long-term follow-up is necessary in case of tumors that are malignant or show atypical features
• The prognosis of Glomus Tumors is based on a set of several factors including whether it is benign or malignant. Benign tumors have an excellent prognosis on suitable treatment, while the prognosis of malignant tumors are based upon the tumor stage, location, and overall health of the individual

Some of the (mostly benign) Glomus Tumor types include:

• Glomuvenous Malformation: It is usually benign and seen in multiple locations; a positive family history is often present. Occasionally, the tumor is mixed with smooth muscles, in which cases it is called a glomangioma. Most glomangiomas are benign tumors
• Symplastic Glomus Tumor: If a Glomus Tumor shows atypical nuclear features (nuclear pleomorphism), but does not show abnormal cell proliferation; is less than 2 cm in size and is not located deep in the body, and does not show tumor necrosis, it is called a symplastic Glomus Tumor

Who gets Glomus Tumors? (Age and Sex Distribution)

• Glomus Tumors are very rare tumors; these constitute less than 2% of all soft tissue tumor types
• Most commonly, Glomus Tumors are benign in nature. In very rare to extremely rare cases, they are known to be atypical or malignant
• It may affect individuals of any age, though it is frequently observed in young adults
• Solitary tumors are often found in slightly older adults than multiple tumors (which is found in younger adults)
• Glomus Tumors can occur in various parts of the body and both male and female genders are equally affected. However, tumors that form under the nail beds (subungual Glomus Tumors) are much more common in women than men
• All racial and ethnic groups may be affected and no preference is noted

What are the Risk Factors for Glomus Tumors? (Predisposing Factors)

Currently, the risk factors that contribute to Glomus Tumor development are unknown.

• A positive family history is seen when multiple lesions are present; in such cases, there is an autosomal dominant pattern of inheritance noted
• Neurofibromatosis type 1 (NF1, a genetic disorder) association is seen with Glomus Tumors that appear on the fingers and toes (subungual Glomus Tumors), typically when more than one digit is involved
• Bleb nevus syndrome are associated with glomus cell proliferation due to a condition called glomovenous malformation

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Glomus Tumors? (Etiology)

The exact cause and mechanism of formation Glomus Tumor is unknown.

• In general, Glomus Tumors are observed to have a variety of mutations
• Inherited tumors show gene mutations; the glomulin gene in chromosome 1 is involved in such cases
• Multiple Glomus Tumors are known to be inherited in an autosomal dominant manner
• Some research studies inform that Glomus Tumors may be malformations rather than true tumors

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of Glomus Tumors?

The following are the signs and symptoms of Glomus Tumors. They are based on the characteristic features of the tumor, including whether they are benign, atypical, or malignant.

Benign Glomus Tumor signs and symptoms may include:

• The tumors are superficial (occurring on or just below the skin) in a vast majority of cases; they may also be infrequently deep-seated and occur at several locations
• The common sites are the upper extremities, with involvement of the hand, wrist, and fingers. Also, the tumor is commonly seen to affect the foot and toes
• On the skin, the tumors are painful and may appear as blue nodules, usually 1 cm in size or less. The pain may increase on touch or on exposure to cold
• On the finger nail or toenail, the tumor may appear as a very painful, raised swelling with underlying skin discoloration. The nail may be deformed. These are known as subungual Glomus Tumors, and these are mostly benign
• Glomus Tumors on the arms and legs can be present as papules, or small raised swellings

Atypical and Malignant Glomus Tumor signs and symptoms may include:

• In general, malignant tumors are more common in deep tissue locations than superficial locations
• Deep-seated tumors may occur in the digestive tract, urinary bladder, male genitals, chest cavity, lungs, and bones. They may occur at any location in the body and infiltrate the surrounding tissues
• Tumors present inside the body tissues may be irregularly-shaped and have fewer specific signs and symptoms. It may also depend upon the location of the tumor
• Tumors present in deep body tissues are about or over 2 cm in size

Several body sites may be affected, though infrequently, by atypical and malignant tumors. Based on the location, the tumors are known as:

• Gastrointestinal Tract Glomus Tumor
• Glomus Tumor of Urinary Bladder
• Glomus Tumor of Penis
• Mediastinal Glomus Tumor
• Pulmonary Glomus Tumor
• Glomus Tumor of Bone

How is Glomus Tumors Diagnosed?

A diagnosis of Glomus Tumor may include the following:

• A thorough physical exam and complete evaluation of medical history
• The following classical triad of symptoms may be noted for superficial tumors:
  • Severe pain
  • Point tenderness
  • Cold sensitivity
• The following tests may be used for superficial tumors, but are not applicable for deep-seated tumors:
  • Hildreth’s test: The limb with the tumor is elevated to drain blood away from the site of the tumor. After elevation, a tourniquet is tied and subsequently, the tumor is touched. The pain upon touch should be significantly reduced. But when the tourniquet is removed, the pain on touch suddenly increases
  • Love’s pin test: Individuals should experience severe pain and subsequent decrease in pain, when the skin on top of the tumor is pushed using a fine object, such as a paper-clip, a pinhead, a toothpick, or a ball-point pen tip
• CT scan or MRI scan of the affected region, for deep-seated tumors
• Tissue biopsy of tumor specimen:
  • A biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
  • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
  • Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies, to assist in the diagnosis

Atypical Glomus Tumors are classified as tumors that do not have all the criteria of malignancy, but have some atypical features. During a diagnostic work-up of a tissue biopsy by a pathologist, the following features may be observed under a microscope that is indicative of malignancy:

• The tumor cells have atypical features in the nucleus
• The tumor has an increased cell division activity (mitotic activity) with atypical mitotic forms
• Parts of the tumor may have a completely benign appearance; this means that the tumor may have a malignant features in one area with some areas that are entirely benign

Note:

• Tumors that are deep-seated are generally difficult to diagnose due to their non-specific nature
• For most benign tumors that do not cause significant signs and symptoms, the diagnosis is often delayed

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Glomus Tumors?

Glomus Tumors may be associated with the following complications:

• Complications from benign tumors are generally not noted
• Superficial lesions may present severe pain
• The tumor can recur locally after its surgical removal
• Malignant tumors are often aggressive and are known to metastasize to various body parts

How is Glomus Tumors Treated?

The treatment of Glomus Tumor depends on whether the tumor is benign, atypical, or malignant. The treatment may involve the following measures:

• The healthcare provider may recommend a ‘wait and watch’ approach for small, asymptomatic and benign tumors in superficial locations
• Simple excision and complete removal of the tumor: It is the most effective treatment available for most of the tumors
• Multiple tumors may be treated through any of the following means:
  • Laser therapy
  • Injection of hypertonic saline
  • Sclerotherapy
• Generally, chemotherapy or medical therapy (treatment using medications) is not effective for treating Glomus Tumors
• Long-term follow-up care with regular screening and check-ups are important

How can Glomus Tumors be Prevented?

Currently, there are no effective preventative methods available for Glomus Tumor. Avoiding exposure to severe cold may reduce aggravation of the signs and symptoms.

What is the Prognosis of Glomus Tumors? (Outcomes/Resolutions)

• With appropriate treatment, the prognosis of benign Glomus Tumor is typically excellent
• The prognosis of atypical tumors depend on whether they are benign or malignant
• The prognosis of malignant tumor depends upon a set of several factors, which include: 
  • Stage of tumor: With lower-stage tumors, when the tumor is confined to site of origin, the prognosis is usually excellent with appropriate therapy. In higher-stage tumors, such as tumors with metastasis, the prognosis is poor
  • Location of tumor: Tumors at locations with potential to damage vital organs, such as tumors in the chest and GI tract, have poor prognosis than tumors that are located in the extremities (arms or legs)
  • The surgical resectability of the tumor (meaning if the tumor can be removed completely)
  • Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
  • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
  • Whether the tumor is occurring for the first time or is a recurrent tumor. Recurring tumors have worse prognosis compared to tumors that do not recur
  • Response to treatment: Tumors that respond to treatment have better prognosis compared to tumors that do not respond to treatment

Additional and Relevant Useful Information for Glomus Tumors:

Please visit our Cancer & Benign Tumor Health Center for more physician-approved health information:

https://www.dovemed.com/diseases-conditions/cancer/