Carcinoma in situ

ICD-11

2E64

Synonyms

Bowen’s disease (skin), erythroplasia of Queyrat (glans penis), leukoplakia (mucous epithelia).

Epidemiology

Incidence 15/100,000/year in persons with white skin.

Definition

Carcinoma in situ (intraepidermal and intraepithelial carcinoma).

Aetiology & Pathogenesis

UV exposure, immunosuppression, HPV, tobacco, betel nut.

Signs & Symptoms

Circumscribed erythematous (sometimes scaly) patch or plaque, persistent whitish mucosal lesions.

Localisation

Sun-exposed skin, genitalia, buccal mucosa.

Classification

Grade 1 to 3 according to progression and involvement by histology.

Laboratory & other workups

None

Dermatopathology

Orthohyperkeratosis (pink) alternating with parakeratosis (blue). Abnormal keratinocytes. Pseudopod-like proliferation of the epidermis. Solar elastosis in the upper dermis.

Complications

Transition to invasive cutaneous or mucosal squamous cell carcinoma.

Diagnosis

Diagnosis relies on clinical picture and histology.

Differential diagnosis

Depending on localisation (lips, buccal or genital mucosa): superficial basal cell carcinoma, bowenoid papulosis, extramammary Paget’s disease. Confirmation by histology.

Prevention & Therapy

Depends on localisation and histological type. For example: excision, cryosurgery, photodynamic therapy, radiotherapy, 5-fluorouracil or imiquimod cream.

3.3.2 Carcinoma in situ