bubble_chart Overview

Basal cell epithelioma, previously known as basal cell carcinoma, is a malignant skin tumor originating from the basal layer of the epidermis or skin appendages, composed of tumor cells resembling basal cells. This disease progresses slowly and rarely metastasizes.

bubble_chart Etiology

Disease cause: May be related to sun exposure, excessive X-ray irradiation, frequent contact with tar and other substances. It can also occur secondary to burn scars, chronic ulcers, seborrheic keratosis, and actinic keratosis.

Histopathology: Tumor cell nests are located in the dermis, with tumor cells resembling basal cells, featuring large, oval nuclei, scant cytoplasm, indistinct cell boundaries, and inconspicuous intercellular bridges. The peripheral cells of the tumor nests are columnar and arranged in a palisade pattern, while the central tumor cells are round, oval, or spindle-shaped. Occasionally, abundant pigment granules may be observed, and the tumor cell nests are separated from the surrounding stroma.

bubble_chart Clinical Manifestations

This disease is more common in men over 40 years old, particularly among outdoor workers. In 75% of cases, the skin lesions occur on the face and neck, and clinically, they are usually solitary, with the following types:
(1) **Nodular ulcer type**: Most commonly seen on the face. Initially, it presents as a small, firm nodule with a waxy sheen and superficial telangiectasia. The nodule slowly expands peripherally, forming a round or oval, yellowish or grayish-white lesion. After several years, an ulcer develops in the center, covered with a brown crust. The edges roll inward, appearing shiny, hard, and steep, forming a raised, dike-like border. The base consists of red granulation tissue covered by a thin crust, which bleeds easily upon touch. The ulcer gradually extends deeper and wider, causing significant destruction, hence also referred to as **rodent ulcer** (Figure 17).

(2) **Pigmented type**: Similar to the nodular ulcer type, but the nodules are flatter, and the ulcer is shallow, with dark brown or black-brown pigmentation. It is sometimes mistaken for melanoma.
(3) **Morphea-like or fibrosing type**: In the early stage, a flat papule or depression appears on the face, which later expands into a sclerotic, yellowish patch with a smooth, shiny surface and indistinct borders. It remains intact for a long time before eventually ulcerating.
(4) **Superficial type**: Mostly seen on the chest, presenting as scaly erythema. The lesions may be multiple, slightly infiltrated, and slowly expanding. The ulcer is superficial, resembling erosion, and heals with atrophic scarring. A few lesions may have linear or pearl-like borders.
(5) **Fibroepithelioma type**: Often occurs on the back and abdomen. The nodules are raised, moderately firm, and smooth with a pinkish hue. The lesions may be multiple, resembling fibromas.

**Diagnosis**: Based on clinical manifestations and histopathology, the diagnosis is not difficult.

bubble_chart Treatment Measures

Treatment: Different measures are taken based on the location and size of the tumor. (1) **Radiation Therapy** Radiation has shown satisfactory efficacy for this condition. (2) **Surgical Treatment** Surgical excision is performed, followed by X-ray irradiation. If metastasis is present, lymph nodes are cleared. (3) **Physical Therapy** For small tumors, carbon dioxide laser therapy, cryotherapy, or electrocautery can be used, all of which yield good results. (4) **Topical Medication** A 5% fluorouracil ointment can be applied externally twice daily for four consecutive weeks.

bubble_chart Complications

[Efficacy Evaluation]

bubble_chart Differentiation

[Epidemiology]