Introduction

Pyogenic granuloma (Pyo-ge-nic gra-nu-lo-ma) is an abnormal growth which is a non-cancerous growth arising from blood channels occurring on the skin or the lining of internal organs called mucosa. Another name for it is a lobular capillary haemangioma.¹ The name does not correctly describe the condition because it does not arise from any infection, as depicted in ‘pyogenic’ and it is also not a ‘granuloma’.²

It was first described in the literature in 1897 by Ponce and Dor.³ It is sometimes called a pregnancy tumour or pyogenic granuloma gravidarum because of its common occurrence during pregnancy, seen in 5% pregnant women. The explanation for its common presence in pregnant women is that there is an excessive response from the mucosa in pregnancy to irritants due to the level of pregnancy hormones in the mother being higher than usual.⁴ 

Children and young adults commonly have pyogenic granuloma, while elderly patients rarely have it. It normally appears as a red fleshy mass that is prone to bleeding on trivial trauma, with the opening up of the skin called ulcers. It may occur following a trauma in 7-24% of cases, but for the majority of cases, there is no preceding history of an injury.^5,6

The average size is between 0.65 to 1.1 cm, and when it exceeds 2cm, it is called a giant pyogenic granuloma.^7,8 Sizes of up to 16cm long and 25cm wide have been reported.⁹ This giant form is rare, often appearing with an atypical type presentation and may be confused for more severe conditions, which can cause patient anxiety. 

The growth period varies from weeks to months; however, it grows rapidly. Despite this rapid growth, its growth is limited only to the surface, and it does not spread to other parts of the body as cancers do. No report has been made of it changing to cancer. It may, however, recur after treatment with a 15% recurrence rate when treated by surgical removal.⁹

Although rare, it is important to recognise this atypical presentation of pyogenic granuloma because it can be confused with other diagnoses. A high index of suspicion, as well as examination of the surgically removed mass in a histopathology laboratory, helps to identify the giant pyogenic granuloma. 

Etiology 

The cause of giant pyogenic granuloma is unknown. Giant pyogenic granulomas, just like the normal-sized or typical pyogenic granulomas, are thought to occur as a result of the rapid growth of epithelium and formation of new blood vessels (angiogenesis) in response to a stimulus.² The triggers, or risk factors for giant pyogenic granuloma, include the following;

•  Trauma or injury^10,11
•  Reaction of the body to foreign materials such as sutures used for closing wounds¹⁰
• Hormones, especially in pregnancy⁴
• Suppression of the immune system by the presence of HIV infection or cancer, or transplant patients on immunosuppressant medications^3,7,9
• In a majority of patients, no risk factor is identified¹² 

Other risk factors causing pyogenic granuloma in general include;

• Infections such as bacillary angiomatosis caused by Bartonella species⁵
• Medications such as docetaxel, capecitabine and rituximab

Clinical features of giant or atypical PG

Giant or atypical PG is commonly seen in children and young adults with no racial predisposition. They are large, more than 2 cm in dimension, with large reported lesions up to 25cm x 15 cm dimensions.⁹ They present as a single red fleshy mass which bleeds easily even following trivial trauma. Chandra et al. reported an atypical presentation where the lesion had a dirty white colour.¹⁰ Although it commonly occurs as a single lesion, it may sometimes be multiple, either of which appears with a narrow base or a wide base. 

It may occur on the mucosa or skin. The mucosa lesions are common in the head and neck, mainly the oral and nasal mucosa and occur more commonly in women. This is opposed to the skin lesions, which occur more commonly in men.

Common locations where the giant pyogenic granuloma has been described include the scalp,¹⁰ eye¹³, nose⁴, face, external auditory meatus¹⁴, finger,¹⁶ forearm⁷, genitals (penis),^12,15 thigh⁹ and ankle.³

It is mostly painless. Pain is present when there is an infection present. Common complaints leading to hospital visits are the poor cosmetic appearance of the mass and repeated bleeding episodes. 

Depending on the location, other symptoms could include 

• Nose - Difficulty in breathing, obstruction of the nose, alteration in smell 
• Hand- Pain and inability to use the affected digit
• Genitals- Inability to perform sexual intercourse due to pain and bleeding

In comparison with the typical pyogenic granuloma, although the size is the main differing characteristic, other risk factors such as immunosuppression are less prevalent in the typical type. 

The microscopic and histologic appearance is, however, similar for all when viewed under a magnifying microscope. 

Histological characteristics

When a piece of the tissue removed is viewed under the magnifying microscope in a histopathology laboratory, giant or atypical PG appears as an excessive growth of capillaries (tiny blood vessels) with thinned-out surface lining, called epithelium.¹⁵ 

Differential diagnosis

A number of conditions may mimic giant pyogenic granuloma. They include the following;

1. Cancerous conditions such as amelanotic melanoma, squamous cell carcinoma, metastatic carcinoma, penile cancers, angiosarcoma, and kaposi sarcoma
2. Non-cancerous growths, which include vascular lesions, example hemangioma, dermatofibroma 
3. Infectious causes such as genital warts, bacillary angiomatosis, and verruga peruana 

Diagnosis of giant or atypical pyogenic granuloma

In order to make a diagnosis of atypical pyogenic granuloma, the following is required;

1. Obtaining a history of the lesion, including its duration, any preceding history of trauma, history of immunosuppression as related to the use of chemotherapeutic agents in cancer patients, HIV, or transplant patients. 
2. Physical examination of the lesion, noting its size, which is the diagnostic criterion of more than 2cm, location, and number, either single or multiple
3. Blood tests
4. Magnetic resonance imaging scans
5. CT (Computerised tomography) scans
6. Angiography
7. Tissue biopsy and histological examination
   1. This helps confirm the diagnosis and rule out the presence of differentials. The biopsy may be in the form of
   2. Punch biopsy - Taking a little chunk of the tissue using a punch biopsy forceps (punch biopsy) and subjecting it to histology examination
   3. Excision biopsy of the tyre lesion and histopathology

Imaging helps to identify deep-seated lesions in the mouth or nose. This aids in identifying the character of the lesion, its location, size and relation to other structures. Imaging modalities such as angiography help to identify the number of blood vessels contained in the mass or the vascularity of the lesion in preparation for embolisation. This is a form of treatment that reduces the blood entering the growth before surgery is done. This prevents excessive loss of blood when surgery is performed to remove the giant pyogenic granuloma.

Treatment 

The most common treatment for giant pyogenic granuloma is complete surgical excision with a margin of normal tissue to avoid recurrence. This is because the diagnosis is not often easily made, and it is confused with other diagnoses. The advantage of this method is that it serves both as an investigation to identify the diagnosis and a treatment because of its large size.

A recurrence rate of 15% is seen when a pyogenic granuloma is surgically removed. Other treatment options are the following 

• The use of systemic corticosteroids¹⁷
• Laser therapy after curettage is also a recommended treatment option. 
• Curettage and electrocautery an options in the medium-sized pyogenic granuloma, but the problem is recurrence and lack of tissue for pathologic examination 

Complications 

• Bleeding 
• Pain 
• Local disabilities related to their site of occurrence, such as loss of vision, poor sense of smell
• Cosmetic embarrassment due to the size of the lesion 

Frequently asked questions 

What is a giant pyogenic granuloma

A giant or atypical pyogenic granuloma is an abnormal growth of epithelium and capillaries, causing a swelling that exceeds 2 cm in dimension. 

How frequent is a giant pyogenic granuloma 

Giant pyogenic granulomas are rare, occurring infrequently when compared to the typical variant. 

Can a giant pyogenic granuloma bleed profusely 

Yes, a giant pyogenic granuloma can bleed profusely when it is hit or traumatised. This is because the growth itself contains rapidly dividing blood vessels called capillaries. 

Summary 

Giant pyogenic granuloma is are large, >2 cm diameter lesions which arise from abnormal growth of blood vessels and epithelium of capillaries in response to a trigger. The cause is unknown, although identified risk factors for its occurrence include trauma, immunosuppression due to the presence of a malignancy, use of chemotherapeutic agents and the presence of HIV. In most cases, however, no risk factor is identified.

It is a benign, non-cancerous condition. Because of its large size, however, it can be confused for cancer, causing panic or anxiety. Interventions such as clinical examination, sending the specimen for histopathological evaluation can clarify the diagnosis. This is an important diagnosis to consider when the risk factors mentioned above are present in a patient with a non-cancerous growth.