Basal cell carcinoma: Clinical sciences

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Introduction0:00–0:50

Basal cell carcinoma, or BCC for short, is the most common type of skin cancer. It develops on parts of the skin exposed to high levels of sunlight or ultraviolet radiation, such as the head, neck and the upper extremities.
BCC arises from basal cells, which are stem cells responsible for producing new skin cells. They are located in the deepest layer of the epidermis.
Most BCCs are slow growing, so they can go unnoticed for a long period of time, and they rarely metastasize. Treatment is based on risk of recurrence rate, and can be surgical or medical.
Alright, when a patient presents with a chief concern suggesting a BCC, the first step is to obtain a focused history and physical.

History and Physical Exam0:50–2:29

Typically, patients notice a skin lesion that has been changing gradually in size or color, or one that won’t heal. Additionally, they might have risk factors like fair skin complexion and prolonged sun exposure.
Patients may have a family history of cancers, or personal history of genetic disorders or immunosuppression. Here’s a high yield fact!
Xeroderma Pigmentosum is a rare autosomal recessive genetic condition characterized by impaired DNA repair mechanisms. When the UV rays from the sunlight cause damage to the skin cell DNA, the body is not able to repair the damage.
As a result, these patients are at increased risk of developing skin cancers like BCC.Now, on physical exam, you can expect to see a skin lesion that looks like a small raised bump or non-healing sore.
The nodule can be translucent, shiny, waxy, or “pearly” in appearance, or it can appear as an ulcer with central depression and raised, rolled or elevated edges.
Occasionally, you might see surrounding telangiectasia, which is evidence of abnormal angiogenesis associated with skin malignancies.In the late stages, BCCs can become quite large, with a fungating appearance indicating local invasion.
These findings should lead you to suspect BCC. The best way to confirm your diagnosis is to biopsy the lesion.

Biopsy2:29–4:22

Depending on the size, location, and appearance of the lesion, you can perform a punch, shave biopsy, incisional or excisional biopsy.The biopsy results showing nests and island cells, peripheral palisading, fibrosis, clefting, increased mitotic activity, multinucleated cells or hyperchromatic nuclei, cystic spaces, ulceration or deep invasion into the subcutaneous tissueThese findings confirm your diagnosis of BCC.
If biopsy findings are not consistent with BCC then consider an alternative diagnosis.The three most common types of BCC are nodular, superficial, and infiltrative.
Nodular BCC is the most prevalent subtype, comprising over 60% of cases. It usually presents with the classic raised, pearly, or waxy appearance with rolled edges.
Some might have central ulceration. Superficial BCC is the second most common, and often appears red and scaly.
It can be difficult to differentiate it from other lesions like squamous cell carcinoma, eczema, or psoriasis. On the other hand, infiltrative BCC are flat, white, scar-like in appearance.
This is the most aggressive subtype of the three. Other rare forms of BCC include morpheaform, micronodular, basosquamous, nodulocystic, follicular, infundibulocystic, neurotropic, and pleomorphic.DMT 3 Okay, let's move on and talk about treatment.

Assess Recurrence Risk4:22–4:49

The management of BCC is guided by first assessing the risk of recurrence. This is calculated by several factors, including size and location of the lesion, clinical characteristics as well as histological features.
Here’s a clinical pearl! Unlike other cancers, TNM staging is not typically used in BCC because they grow slowly and do not tend to metastasize.Okay, so a lesion is considered to be a low recurrence risk if it’s a primary lesion smaller than 20 mm in size, with well defined borders, and it’s located on the trunk or extremities.

Low Recurrence Risk 4:49–6:15

Histopathology shows a nonaggressive growth pattern like nodular or superficial subtypes. The treatment of these lesions include curettage and electrodesiccation if they’re small.
This procedure removes the lesion by scraping it with a curette, then using an electric current to destroy any remaining tumor cells.
For larger lesions, surgical excision can be performed to remove the entire lesion. Surgical excision can be done with wide local excision or Mohs micrographic surgery if wide local excision is not feasible or if the lesion is in an area that’s highly visible for cosmetic reasons.
A number of medical treatment options are also available for patients who are not candidates for an excision. 5-Fluorouracil, also known as 5-FU, and imiquimod are topical therapies that stimulate the body’s immune response to promote destruction of the tumor cells.
Other options include cryotherapy with liquid nitrogen, photodynamic therapy, and primary radiation therapy. Once the treatments are complete, patients should return for routine skin exams every 6 to 12 months.Alright, now let’s go back and talk about high recurrence risk lesions.

High Recurrence Risk 6:15–7:25

These are tumors greater than or equal to 20 mm in diameter located on the trunk or extremities, or lesions of any size located on the head, neck, hands, feet or genitalia.
Lesions will also have poorly defined borders. Patients who are immunocompromised or have recurrent lesions are also considered to be at high risk.
On histopathology, high risk lesions are- micronodular, morpheaform, sclerosing, mixed infiltrative, basosquamous, or carcinosarcomatous.
Additionally there can be perineural involvement.The mainstay of treatment for high risk lesions is surgical excision, which can be wide local excision or Mohs micrographic surgery.
For patients who are not surgical candidates, non-surgical options can be offered, including radiation therapy, or systemic therapies like chemotherapy or immunotherapy.
Lastly, after successful treatment, patients should return for routine skin exams every 3 to 6 months.Alright, as a quick recap… Basal cell carcinoma is one of the most common types of skin cancer, and it’s caused by exposure to sunlight and UV radiation.

Review7:25–8:12

Classically, it looks like a shiny waxy nodule with central ulceration and rolled borders. Diagnosis is confirmed with a biopsy, and treatment is based on the risk of recurrence.
Low recurrence risk lesions can be treated with curettage and electrodessication, surgical excision, topical medical therapy, cryotherapy, and photodynamic or radiation therapy.
For high risk lesions, surgical excision is highly recommended, but non-surgical therapies such as radiation, chemotherapy or immunotherapy can be offered for patients who are
Basal cell carcinoma: Video, Causes, and Symptoms | Osmosis