Breslow's thickness

Breslow's Thickness is a medical term used in the context of melanoma, a type of skin cancer. It is a measurement of the depth of invasion of the melanoma into the skin. Named after Dr. Alexander Breslow, a pathologist, who first proposed the measurement in 1970, Breslow's Thickness is a significant factor in the staging, prognosis, and treatment planning of melanoma.

Definition

Breslow's Thickness is defined as the total vertical height of the melanoma, measured from the top of the granular layer (or bottom of the ulcer) to the deepest point of tumor invasion. It is usually measured in millimeters and can range from less than 0.1 mm to greater than 4.0 mm.

Clinical Significance

The depth of invasion of melanoma, as measured by Breslow's Thickness, is a critical factor in determining the prognosis of the disease. Thinner melanomas generally have a better prognosis than thicker ones. Breslow's Thickness is also used to guide treatment decisions, including whether a sentinel lymph node biopsy should be performed.

Measurement

Breslow's Thickness is measured using an ocular micrometer in the microscope eyepiece when viewing the histological slide of the melanoma. The measurement is taken from the granular layer of the epidermis to the deepest part of the tumor.

Staging and Prognosis

The American Joint Committee on Cancer (AJCC) uses Breslow's Thickness as part of its staging system for melanoma. The AJCC staging system also takes into account other factors such as ulceration and mitotic rate.

Treatment

The treatment of melanoma is guided by the Breslow's Thickness. For thin melanomas (less than 1.0 mm), wide local excision of the tumor is usually sufficient. For thicker melanomas, additional treatments such as sentinel lymph node biopsy, systemic therapy, or radiation therapy may be considered.

See Also

• Melanoma
• Skin cancer
• Cancer staging
• Prognosis
• Pathology