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

• Abrikossoff Tumour of Vulva
• Granular Cell Tumour of Vulva
• Vulvar Granular Cell Tumor

What is Granular Cell Tumor of Vulva? (Definition/Background Information)

• Granular Cell Tumor (GCT) of Vulva is a common and ‘mostly’ benign tumor of the soft tissue that occurs in the vulva (area around the external opening of the vagina). About 15% of the GCTs are found in the vulva of middle-aged women, in a majority of cases
• Benign granular cell tumors are also found within the muscles, tendons, ligaments, soft tissues, and rarely within lymph nodes. Presence of GCT within the lymph nodes is a difficult problem for the doctors. This is because it is difficult to tell whether the presence of such tumors in the lymph nodes are due to a metastasis from a different body site, or if the GCT originated within the lymph nodes itself (primary site)
• In general, Granular Cell Tumor of Vulva forms as a slow-growing solitary mass on the vulva. Even though most are asymptomatic, some tumors may present with pain and itching in the vulvar region
• The treatment for Granular Cell Tumor of Vulva involves surgery. However, tumors with infiltrative margins can recur following their surgical removal
• The prognosis of Vulvar Granular Cell Tumor is typically excellent in a vast majority of cases, since it is a benign tumor. However, around 2% of the tumors are known to undergo malignant transformations

Who gets Granular Cell Tumor of Vulva? (Age and Sex Distribution)

• Granular Cell Tumor of Vulva is a rare tumor that is observed both in adult women and in young girls (to a lesser extent). Most tumors are observed in middle-aged women
• Generally, no preference for any race or ethnic group is noted

What are the Risk Factors for Granular Cell Tumor of Vulva? (Predisposing Factors)

• No documented risk factors have been reported for Granular Cell Tumor of Vulva
• Even though GCTs do not usually run in families, rare cases of increased incidence within families, have been reported

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 Granular Cell Tumor of Vulva? (Etiology)

• The exact cause of Granular Cell Tumor of Vulva is unknown. Some researchers note that GCT may be a tumor of neural origin (relating to a nerve)
• Researchers have documented certain genetic changes within the tumor. However, cases where these specific genetic mutations have been observed are rare. Thus, studies regarding genetic changes are limited
• Even though rare cases of familial granular cell tumors have been noted, the tumor is not associated with any known congenital syndrome

What are the Signs and Symptoms of Granular Cell Tumor of Vulva?

The signs and symptoms of Granular Cell Tumor of Vulva may include:

• Granular cell tumors are usually present as a slow-growing, generally subcutaneous mass in the vulva (commonly in the labium majus)
• GCT may be a solitary, firm, and well-circumscribed mass; some tumors may be locally infiltrative and poorly-circumscribed
• Some tumors can also be seen on the clitoris, the perineum, the perianal region, or at the pubic bone
• The tumor is not painful and is not associated with any significant signs and symptoms
• However, infrequently these tumors may be itchy and painful to touch
• In general, with GCT, about 1 in 10 individuals may simultaneously have multiple tumors in the body

How is Granular Cell Tumor of Vulva Diagnosed?

A Granular Cell Tumor of Vulva is diagnosed using the following tools and methods:

• Evaluation of the individual’s medical history and a thorough physical (pelvic) examination
• Ultrasound scan of the abdomen
• CT or CAT scan with contrast of the abdomen and pelvis may show a well-defined mass. This radiological procedure creates detailed 3-dimensional images of structures inside the body
• MRI scans of the abdomen and pelvis: Magnetic resonance imaging (MRI) uses a magnetic field to create high-quality pictures of certain parts of the body, such as tissues, muscles, nerves, and bones. These high-quality pictures may reveal the presence of the tumor
• Colposcopy:
  • The cervix (including the vagina and vulva) is examined with an instrument, called a colposcope. This helps the physician get a magnified view of the cervix
  • In order for this procedure to be performed, the individual has to lie on a table, as for a pelvic exam. An instrument, called the speculum, is placed in the vagina to keep the opening apart, in order to help the physician visualize the cervix. The colposcope is then used to get a magnified view of the inside

Although the above modalities can be used to make an initial diagnosis, a tissue biopsy of the tumor is necessary to make a definitive diagnosis to begin treatment. The tissue for diagnosis can be procured in multiple different ways which include:

• Fine needle aspiration (FNA) biopsy of the tumor: A FNA biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a FNA biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred
• Core biopsy of the tumor
• Open biopsy of the tumor

Tissue biopsy:

• A tissue 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

Note:

• A tissue biopsy cannot help definitively diagnose a benign GCT from a malignant GCT. A tissue biopsy may show overlapping features between a malignant granular cell tumor and a benign granular cell tumor, when examined under a microscope by a pathologist. Clinical correlation as regards the behavior of the tumor is often necessary for a definitive diagnosis of malignancy. A malignant GCT is diagnosed when the tumor metastasizes to structures away from the primary site of tumor origin
• The granular cell tumors should be clinically and histologically distinguished from other tumors. These tumors include rhabdomyoma, hibernoma, fibroxanthoma, neurofibroma and schwannoma.  A pathologist will help eliminate other tumor types
• Sometimes, the pathologist may perform special studies, which include immunohistochemical stains and histochemical stains. The common immuno stains used are S100 protein, neuron specific enolase (NSE), calretinin, peripheral myelin protein, myelin basic protein (MBP), alpha 1 antitrypsin protein, CD68, and vimentin. These immuno stains are usually positive in granular cell tumors. The GCTs are negative for neural filaments and GFAP immunostains
• The tumors are positive for PAS histochemical stains when examined by the pathologist under a microscope. Even though the tumors are positive for PAS stain, the tumors do not contain glycogen

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 Granular Cell Tumor of Vulva?

There are usually no complications arising from a benign Granular Cell Tumor of Vulva. However, some complications could include:

• Stress and anxiety due to cancer concerns
• The granular cell tumor may become malignant, which is observed in 1 in 50 cases
• A malignant GCT can metastasize to other regions of the body. Extensive metastasis may result in fatalities
• Incompletely removed tumors are known to recur in some cases. The recurrence rate is seen to vary from 2-8%.  The chances of recurrence of a completely excised tumor is very less

How is Granular Cell Tumor of Vulva Treated?

The treatment measures for Granular Cell Tumor of Vulva include:

• Pain medications, in case of tumors causing pain
• Surgical intervention with complete excision results in a complete cure, in a majority of cases. Occasionally, the tumor can recur after its surgical removal
• It is easier to completely remove tumors that are well-circumscribed. Poorly-circumscribed tumors with infiltrative margins make complete surgical tumor removal more difficult
• Often, it is difficult to distinguish between a benign GCT and a malignant GCT, based upon the tissue examination by a pathologist under a microscope. Hence, a complete removal of the tumor is recommended
• Radiation therapy and chemotherapy are not usually required, unless a malignant transformation of the Vulvar GCT is observed
• Post-operative care is important: Minimum activity level is to be ensured until the surgical wound heals
• Follow-up care with regular screening and check-ups are important

How can Granular Cell Tumor of Vulva be Prevented?

• The cause of Granular Cell Tumor of Vulva is unknown; hence, there are no known methods to prevent the tumor occurrence
• Medical screening at regular intervals with scans and physical examinations are important and are advised

What is the Prognosis of Granular Cell Tumor of Vulva? (Outcomes/Resolutions)

• The prognosis of a benign Granular Cell Tumor of Vulva is excellent with adequate treatment. If the tumor is incompletely removed, a benign tumor may have local recurrence
• Even though 98% of the GCTs are benign, malignant transformations and metastasis have been noted in 2% of the tumors. In such cases, the prognosis of the tumor depends upon a set of factors including the stage of the tumor, age of the individual, and the response to appropriate therapy

Additional and Relevant Useful Information for Granular Cell Tumor of Vulva:

There are two variants of granular cell tumor (GCT) and these include:

Granular cell epulis of infancy:

• Granular cell epulis of infancy. This is a rare tumor that occurs on the gums of the newborn. It is more common in females. A pathologist would be able to arrive at a diagnosis of granular cell epulis of infancy after examination under microscope and also after performing a variety of special studies called immunostains. This tumor is negative for S100 protein, neuron specific enoloase (NSE), laminin and, myelin basic protein (MBP), CD-57 and alpha-1 antitrypsin protein. The above stains show a pattern that is different from the staining pattern of a classical granular cell tumor. This difference in staining pattern helps in the correct diagnosis
• This tumor is usually slow-growing. The tumor does not grow after birth and there is no tendency for local recurrence. In majority of cases a congenital granular cell tumor would either stop to grow or completely disappear without treatment
• This type of tumor tend to be smaller size compared to traditional soft tissue tumor (about 1 cm along the larger dimension)
• There are no documented cases of a congenital granular cell tumor undergoing a malignant transformation to develop into a malignant granular cell tumor

Malignant granular cell tumor:

• Malignant granular cell tumor is a very rare variant of the granular cell tumor. Less than 1 in 50 GCTs would have tendency to become malignant. Malignant granular cell tumor can occur at any age, but is more commonly seen in ages between 30-50 years. It is also more common in females, than males. Unlike benign granular cell tumor, which is more common in head and neck region; the malignant variant of GCT is more common in the arms and legs (particularly common in the thigh region). Unlike benign granular cell tumors, the malignant tumors grow more rapidly
• The skin over the malignant granular cell tumor could often break, causing ulceration. The tumor can spread to the surrounding areas through infiltration, and spread to other distant regions of the body too (metastasis)
• When examining a biopsy of the tumor, a pathologist and would be able to distinguish benign GCT from a malignant one, after examination under a microscope. Normally, a malignant granular cell tumor would have a higher amount of abnormal cells and increased proliferation (growth). Clinical correlation is very important to arrive at a diagnosis of malignant granular cell tumor. A malignant granular cell tumor may show the following features: Size greater than 3 cm (along the larger dimension), ulceration of overlying skin, and a rapid increase in size