Squamous cell carcinoma in situ is a superficial squamous cell neoplasm. Diagnosis is by biopsy. Treatment depends on the tumor’s characteristics and may involve curettage and electrodesiccation, surgical excision, topical chemotherapeutics, electrocautery, or cryosurgery.
(See also Overview of Skin Cancer.)
Squamous cell carcinoma in situ (formerly called Bowen disease) is most common in sun-exposed areas but may arise at any location.
Symptoms and Signs of Squamous Cell Carcinoma in Situ
Lesions can be solitary or multiple. They are red-brown and scaly or crusted, with little induration; they frequently resemble a localized thin plaque of psoriasis or dermatitis or a dermatophyte infection.
DR P. MARAZZI/SCIENCE PHOTO LIBRARY
Diagnosis of Squamous Cell Carcinoma in Situ
Biopsy
Squamous cell carcinoma in situ is often suspected when a rash secondary to a disorder such as psoriasis or atopic dermatitis fails to respond to treatment.
Diagnosis is by biopsy, which shows full-thickness epidermal dysplasia but no dermal involvement.
Treatment of Squamous Cell Carcinoma in Situ
Treatment with topical chemotherapeutics
Removal or ablation via local methods
Treatment of squamous cell carcinoma in situ depends on the lesion’s characteristics and may involve topical chemotherapeutics, curettage and electrodesiccation, surgical excision, electrocautery, or cryosurgery.
Prevention of Squamous Cell Carcinoma in Situ
Because many skin cancers seem to be related to ultraviolet (UV) exposure, a number of measures are recommended to limit exposure.
Sun avoidance: Seeking shade, minimizing outdoor activities between 10 AM and 4 PM (when sun's rays are strongest), and avoiding sunbathing and the use of tanning beds
Use of protective clothing: Long-sleeved shirts, pants, and broad-brimmed hats
Use of sunscreen: At least sun protection factor (SPF) 30 with broad-spectrum UVA/UVB protection, used as directed (ie, reapplied every 2 hours and after swimming or sweating); should not be used to prolong sun exposure
