Carcinoma in situ

Cutaneous carcinoma in situ (Bowen disease) is a clinical form of in situ squamous-cell carcinoma. Common in fair-skinned elderly on sun-exposed sites (especially face/legs); also trunk/vulva. Clinical: asymmetric, well-demarcated scaly erythematous plaque with clear borders. Slow progression, confined to epithelium for years. Pathology: full-thickness squamous atypia; loss of epithelial polarity; normal cells replaced by pleomorphic/multinucleated bizarre cells; mitoses/keratinization; intact basement membrane; follicular infundibulum often involved.

Common Symptoms

Pernicious anemia; anorexia; cachectic facies; chest tightness; weight loss

Causes and Pathogenesis

Carcinoma in situ = full-thickness epithelial atypia (severe) without basement-membrane breach (cervix/esophagus/skin). Epithelium covers body surfaces; below is stroma/dermis. Cancer cells confined to epithelium, no stromal invasion/distant metastasis; called 'pre-invasive' or 'stage 0' cancer.

Treatment

Cryotherapy, curettage/electrocautery, photodynamic therapy

Preventive Measures

Early signs subtle; slow-growing mass at limbus. Suspected cases: excise + pathology. Recurrence re-excised = curable. Early cancer; easy cure; excluded from critical-illness policies. Common: cervical in situ SCC, intraductal breast carcinoma, Paget disease, Bowen disease, bladder in situ transitional-cell carcinoma, laryngeal in situ SCC.

Department to Visit

It is recommended to visit the General department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.