Keratoacanthoma abbreviated as KA is considered as a common skin tumor of low intensity. This tumor does not tend to invade or metastasize. The tumor in this case is believed to have developed from the hair follicle neck. Many experts consider the condition to be SCC or Squamous Cell Carcinoma. It is described that Keratoacanthoma is a variant of distinguished squamous cell carcinoma this is because approximately 6% of KA can manifest in form of SCC if left untreated. The condition found commonly on skin region which is exposed to sun mostly; it is observed on face, hands and forearms.
Keratoacanthoma is characterized through its dome shape which is symmetrical and surrounded by smooth lining of inflamed skin. It is often capped with debris and scales of keratin. It grows rapidly and may turn larger in size in few days or weeks. If the condition is left untreated it may starve, undergo necrosis, shed and then heal leaving a scar. Though it is declared that KA is non-malignant distinct tumor, but some experts indicated that it can be invasive and aggressive progressing to squamous cell cancer; hence, timely treatment of the condition is crucial.
It is difficult to confirmedly determine the intensity of KA as only a minute fragment of larger Keratoacanthoma is obtained as sample for pathologic evaluation. No diagnosis can be conducted if keratin debris is submitted. Squamous cell carcinoma is often detected through deep core of the tumor or peripheral deep wedge. A true and correct diagnosis can be made only when the entire structure of the Keratoacanthoma is submitted.
Types of Keratoacanthoma
There are different types of Keratoacanthoma which are as follows:
- Giant Keratoacanthoma is a cutaneous variation of Keratoacanthoma and may reach to dimension measuring in centimeters.
- Keratoacanthoma centrifugum marginatum is another cutaneous variant of Keratoacanthoma characterized through multiple tumor development in localized region
- Multiple Keratoacanthoma also called Fergusone Smith syndrome which is a self healing KA. This condition is characterized with hundreds of KA
- Solitary Keratoacanthoma is also referred to as Subungual Keratoacanthoma. It is benign but fast growing aggressive tumor which may sometimes occur in nail apparatus
- Generalized eruptive keratoacanthoma or Generalized Eruptive Keratoacanthoma of Grzybowski is a condition wherein hundreds of thousands of minute follicular keratotic papules occur over entire body.
Keratoacanthoma occurs from hair follicles neck but the reason is not determined. Some experts hypothesize that KA tumor often occurs in people who are over age. Studies indicate that ultraviolet light emitted from sun stimulates development of KA, similar as in case of squamous cell cancer. Similar to SCC some sporadic cases indicate co-infection of HPV or Human Papilloma Virus.
Diagnosis of Keratoacanthoma
Keratoacanthoma diagnosis is primarily done through examination in clinical settings and evaluating medical history of the affected individual. To determine whether the condition is KA doctor would focus on certain characteristics of the condition which usually includes fleshy elevated nodule with uneven crater shape and hyperkeratotic core. The patient often experience fast rising dome shape tumor on skin mostly exposed to sun light.
To confirm the diagnosis a skin biopsy is often suggested to the patient. Often a shave biopsy will only reveal keratin shards. Performing deep punch biopsy will help in determine a distinguished, unusual squamous cell of actinic keratosis or carcinoma of squamous cell. A correct and confirmed diagnosis can only be done if the pathologist can perform evaluation of the entire lesion which is rarely the case. It is practically believed that diagnosis should be “well distinguished SCC, Keratoacanthoma variant”. This would also allow surgeon to deal with tumor in proper respect using margin controlled invasive treatments such as Mohs Surgery.
Correct diagnosis of Keratoacanthoma often needs appropriate communication between the surgeon and pathologist. Some experts still believe that the condition may not require any surgical intervention. Unfortunately when the condition appears on facial skin it tends to grow into a marble-size tumor before it undergoes necrosis and dies away. It leaves a crater or usually a scar on the affected area. It is said that the morbidity of this tumor is considerable higher than that of basal cell carcinoma.
Treatment of Keratoacanthoma
The treatment of Keratoacanthoma can be obtained through a certified doctor. In general cases wherein the KA tumor has developed on torso, arms and leg Electrodesiccation and Curettage is usually sufficient to treat the condition. In case if one wants to confirm diagnosis of the condition the excision of the entire tumor to provide as a sample may be required. Good margin control treatment can be ensured through Mohs surgery if the condition occurs on facial skin. This also allows minimal tissue removal. Unfortunately, many insurance companies ask the patient to confirm diagnosis before going for such procedures. When Electrodesiccation and curettage technique is adopted there are chances of recurrence of the condition. However, it can be treated through another curettage procedure or excision.