Tissue of origin
The International Classification of Diseases for Oncology (ICD-O) system lists a number of morphological subtypes and variants of malignant squamous cell neoplasms, including:
Papillary thyroid carcinoma (code 8050/3)
Verrucous squamous cell carcinoma (code 8051/3)
Papillary squamous cell carcinoma (code 8052/3)
Squamous cell carcinoma (code 8070/3)
Large-cell keratinizing squamous cell carcinoma (code 8071/3)
Large-cell nonkeratinizing squamous cell carcinoma (code 8072/3)
Small-cell keratinizing squamous cell carcinoma (code 8073/3)
Spindle-cell squamous cell carcinoma (code 8074/3) It is also known as spindle-cell carcinoma, and is a subtype characterized by spindle-shaped atypical cells. Adenoid/pseudoglandular squamous cell carcinoma (code 8075/3)
Intraepidermal squamous cell carcinoma (code 8081/3)
Lymphoepithelial carcinoma (code 8082/3)Other variants of SCCs are recognized under other systems, such as keratoacanthoma. Other histopathologic subtypes
Erythroplasia of Queyrat
Marjolins ulcer is a type of SCC that arises from a nonhealing ulcer or burn wound. More recent evidence, however, suggests that genetic differences exist between SCC and Marjolins ulcer, which were previously underappreciated.One method of classifying squamous cell carcinomas is by their appearance under microscope. Subtypes may include:

Adenoid squamous cell carcinoma (also known as pseudoglandular squamous cell carcinoma) is characterized by a tubular microscopic pattern and keratinocyte acantholysis. Basaloid squamous cell carcinoma is characterized by a predilection for the tongue base. Clear-cell squamous cell carcinoma (also known as clear-cell carcinoma of the skin) is characterized by keratinocytes that appear clear as a result of hydropic swelling. Signet ring-cell squamous cell carcinoma (occasionally rendered as signet ring-cell squamous cell carcinoma) is a histological variant characterized by concentric rings composed of keratin and large vacuoles corresponding to markedly dilated endoplasmic reticulum.
Centrifugal abdominal lipodystrophy is a skin condition characterized by areas of subcutaneous fat loss that slowly enlarge. : 496–7

See also
Lipodystrophy
List of cutaneous conditions
Skin lesion


== References ==