Skin cancer, a case history

There are three major types of skin cancer. The deadliest is melanoma, followed by squamous cell carcinoma and basal cell carcinoma, the least dangerous. Other skin cancers are listed here.

In 2005, I had a small lesion removed from my upper back. I couldn’t see it but it felt like a pimple that bled and would not go away. The biopsy showed a basal cell carcinoma. The dermatologist excised it with a large margin of tissue around it and started me on annual skin checks.

Basal cell carcinoma on the arm, similar in appearance to that on my back

Basal cell carcinoma (not mine but likely similar). The tumor has a distinct border with the adjacent skin (“well circumscribed”) and is composed of large lobules of crowded cells with dark nuclei.

Although I have no family history of skin cancer, it may have been caused by a bad sunburn 25 years previous when I was a college student walking around Fort Lauderdale without a shirt.

During an annual skin check in December 2022, my dermatologist noticed the lesion below on my lower back and did a biopsy.

Lesion on the lower back, December 2022. Note the irregular borders, which are highly suspicious for skin cancer.

The biopsy and excision showed a squamous cell carcinoma in situ, also called Bowen disease or early squamous cell cancer.

These two images (not from my skin cancer) show atypical squamous cells (the usual cells in the skin) extended throughout the epidermis of the skin (“full thickness”), but with no invasion into the dermis or other deeper layers.

“In situ” means that the cells are malignant but do not yet have the properties to move; i.e. they cannot go deeper or metastasize elsewhere in the body. Excision is considered adequate treatment if the tumor is removed with a negative margin (i.e. there is no tumor at the edge of the excision).

No further treatment of this lesion is needed, but the annual checks should continue because any risk factors I have (sun exposure, possibly genetics) most likely affect other parts of the skin which may be developing skin cancers too.