Thyroid & Adrenal
Histology of lip carcinoma
|B||Squamous cell carcinoma|
a. The lips represent a transition from external skin to internal mucous membrane that occurs at the vermilion border.
b. The underlying musculature of the orbicularis oris, innervated by the facial nerve, creates a circumferential ring that allows the mouth to have a sphincter-like function.
c. Cancer of the lip is most commonly seen in white men from the ages of 50 to 70 years, but can be seen in younger patients, particularly those with fair complexions. Risk factors include prolonged exposure to sunlight, fair complexion, immunosuppression, and tobacco use.
d. The majority of lip malignancies present on the lower lip (88 to 98%), followed by the upper lip (2 to 7%) and oral commissure (1%).
e. The histology of lip cancers is predominantly squamous cell carcinoma; however, other tumors, such as keratoacanthoma, verrucous carcinoma, basal cell carcinoma, malignant melanoma, minor salivary gland malignancies, and tumors of mesenchymal origin (e.g., malignant fibrous histiocytoma, leiomyosarcoma, and rhabdomyosarcoma), may also present in this location.
f. Basal cell carcinoma does disproportionately present more frequently on the upper lip than lower.
g. Clinical findings in lip cancer include an ulcerated lesion on the vermilion or cutaneous surface, or, less commonly, on the mucosal surface .
h. A nodular or sclerotic lesion may be palpable within the deeper tissues and careful palpation is important in determining the actual size of these lesions.
i. The presence of paresthesias or dysesthesias in the area adjacent to the lesion may indicate mental nerve involvement