Basal cell carcinoma of oral cavity

PPT done using text from schafer and pictures from Neville

1. MALIGNANT TUMORS OF THE EPITHELIAL TISSUE ORIGIN Basal Cell Carcinoma (Basal cell epithelioma , BCC, rodent ulcer)

2. Introduction The most common malignancy in humans Develops most frequently on the exposed surfaces of the skin,the face and the scalp in middle-aged or elderly persons People with fair complexion (often victims)spending time in the sun Slow growing Rarely metastasizes significant local destruction and disfigurement if neglected or treated inadequately

3. Etiology Ultraviolet radiation - most important andcommon cause of BCC Shorter wavelength ultraviolet (UV) radiation (290–320 nm, sunburn rays) Thus chronic sun exposure is important in the development of BCC A long latency period of 20–50 years. Other causes - X-ray exposure, chemical like arsenic, immunosuppression Syndromes like xeroderma pigmentosum (due to an inability to repair UV-induced DNA damage), and nevoid BCC syndrome are characterized by multiple basal cell carcinomas occurring in early age.

4. Etiology Arises from the pluripotential stem cell compartments of the basal layer of epidermis as well as follicular structures (hair follicle stem cells residing just below the sebaceous gland duct)

5. Clinical Features fourth decade of life or later male-to-female ratio is approximately 3:2. white individuals, especially those with very fair skin rare in individuals with dark skin Middle third of the face, but may occur anywhere on the sun-exposed part of skin does not arise from oral mucosa

6. Subtypes The subtypes of basal cell carcinoma are: Nodular basal cell carcinoma Pigmented basal cell carcinoma Cystic basal cell carcinoma Superficial basal cell carcinoma Micronodular basal cell carcinoma Morpheaform and infiltrating basal cell carcinoma

7. Nodular basal cell carcinoma most common begins as a small, slightly elevated papule with a central depression which ulcerates, heals over and then breaks down again Very mild trauma may cause bleeding One or more telangiectatic blood vessels are usually seen coursing over the borders around the central depression It enlarges, but still evidences periods of attempted healing Eventually, develops a smooth, rolled border representing tumor cells spreading laterally beneath the skin Untreated lesions continue to enlarge, infiltrate adjacent and deeper tissues and may even erode deeply into cartilage or bone.

8. Pigmented basal cell carcinoma In addition to features seen in lesions of nodular basal cell carcinoma, lesions of pigmented BCC contain increased brown or black pigment seen more commonly in individuals with dark skin

9. Cystic basal cell carcinoma Translucent blue-gray cystic nodules may mimic benign cystic lesions.

10. Superficial basal cell carcinoma scaly patches or papules pink to red-brown in color , often with central clearing A thread like border is common Erosion is less common than in nodular variety trunk has little tendency to become invasive Mimic psoriasis or eczema but are slowly progressive and not prone to fluctuate in appearance may indicate arsenic exposure

11. Micronodular basal cell carcinoma aggressive variety less prone to ulceration may appear yellow white when stretched firm to touch seemingly well-defined border

12. Morpheaform and infiltrating basal cell carcinoma aggressive basal cell carcinoma subtypes with sclerotic(scar like) plaques or papules border - not well defined and often extends well beyond clinical margins Ulceration, bleeding, and crusting - uncommon mistaken for scar tissue

13. Differential Diagnosis actinic keratosis Bowen’s disease keratoacanthoma melanocytic nevi sebaceous hyperplasia seborrheic keratosis squamous cell carcinoma

14. H/P NODULAR BASAL CELL CARCINOMA Tumor cells of nodular basal cell carcinoma, sometimes called basalioma cells large, hyperchromatic , oval nuclei with little cytoplasm arranged in nests of varying size Cells appear rather uniform mitotic figures - few in number The cells at the periphery - palisading . Early lesions - connection to the overlying epidermis, may be difficult to appreciate in more advanced lesions Increased mucin is often present in the surrounding dermal stroma

15. H/P Cleft formation (retraction artifact ) occurs between BCC nests and stroma because of shrinkage of mucin during tissue fixation and staining Some lobules - areas of pseudoglandular change In the nodulocystic variant, larger tumor lobules may degenerate centrally, forming pseudocystic spaces filled with mucinous debris

16. H/P PIGMENTED BASAL CELL CARCINOMA benign melanocytes in and around the tumor produce large amounts of melanin These melanocytes contain many melanin granules in their cytoplasm and dendrites

17. H/P SUPERFICIAL BASAL CELL CARCINOMA buds of basaloid cells attached to the undersurface of the epidermis Nests of various sizes - upper dermis -show typical palisading periphery

18. H/P MORPHEAFORM AND INFILTRATING BASAL CELL CARCINOMAS more aggressive exhibit growth patterns resulting in strands of cells rather than round nests Thin strands of tumor cells that are embedded in a dense fibrous stroma The strands of infiltrating type tend to be somewhat thicker than those seen in morpheaform basal cell carcinoma, and have a spiky irregular appearance Infiltrating basal cell carcinoma usually does not exhibit the scar like stroma seen in morpheaform type Peripheral palisading and retraction are much less pronounced in morpheaform and infiltrating basal cell carcinoma subclinical involvement is often extensive

19. H/P MICRONODULAR BASAL CELL CARCINOMA aggressive appears as small nodular aggregates of basaloid cells Retraction artifact tends to be less pronounced subclinical involvement is often significant

20. Treatment & Prognosis Surgical excision of the tumor or X-ray radiation number of failures or recurrences subsequent to each type of treatment The prognosis of basal cell lesions is good, since the neoplasm grows slowly, does not tend to metastasize and responds well to treatment