SQUAMOUS CELL CARCINOMA

<|> Squamous cell carcinoma -

Squamous cell carcinoma may arise in any part of the skin or mucous
membrane lined by squamous epithelium but it is more common on sun-
exposed parts of older people.

Predisposing conditions include :

1. Xeroderma pigmentosum
2. Solar keratosis
3. Chronic ulcers
4. Draining osteomyelitis
5. Marjolin's ulcers (old burn scars)
6. Chemical burns
7. Psoriasis
8. HIV infection
9. Ionizing radiation
10. Industrial carcinogens
11. Chewing betel nuts and tobacco in case of cancer of oral cavity.

Common locations :

Face, pinna of ear, back of hands and mucocutaneous junctions such as
lips, anal canal, glans penis.

General appearance :

1. More commonly, an ulcerated growth with elevated and indurated margin.
2. Less often, a raised fungating or polypoid verrucous lesion without
ulceration.

Microscopic features :

1. Irregular downward proliferation of epidermal cells into the dermis.

2. Variation in cell size and shape, nuclear hyperchromatism, atypical mitotic figures, absence of inter-cellular bridges.

3.Whorled arrangement of malignant squamous cells forming "horn pearls". Centers of these horn pearls laminated keratin material.

4. Inflammatory reaction between the collection of tumor cells.

5. Uncommonly, spindle shaped tumor cells and adenoid changes may be seen.

Grading :

Broder's grading system for squamous cell carcinoma :

Grade I - less than 25% anaplastic (tumor) cells
Grade II - 25-50% anaplastic cells
Grade III - 50-75% anaplastic cells
Grade IV - more than 75% anaplastic cells