resembles Bowen disease, presents as reddish papules. Prostate When associated with the prostate, squamous-cell carcinoma is very aggressive in nature. It is difficult to detect as no increase in prostate-specific antigen levels is seen, meaning that the cancer is often diagnosed at an advanced stage. Vagina and cervix Squamous-cell carcinoma of the vagina spreads slowly and usually stays near the vagina, but may spread to the lungs and liver. This is the most common type of vaginal cancer. Bladder Most bladder cancer is transitional cell, but bladder cancer associated with schistosomiasis is often SCC. Diagnosis Medical history, physical examination and medical imaging may suggest a squamous-cell carcinoma, but a biopsy for histopathology generally establishes the diagnosis. TP63 staining is the main histological marker for squamous-cell carcinoma. In addition, TP63 is an essential transcription factor to establish identity of the squamous cells. Classification Cancer can be considered a very large and exceptionally heterogeneous family of malignant diseases, with squamous-cell carcinomas comprising one of the largest subsets. All SCC lesions are thought to begin via the repeated, uncontrolled division of cancer stem cells of epithelial lineage or characteristics. SCCs arise from squamous cells, which are flat cells that line many areas of the body. Some of which are keratinocytes. Accumulation of these cancer cells causes a microscopic focus of abnormal cells that are, at least initially, locally confined within the specific tissue in which the progenitor cell resided. This condition is called squamous-cell carcinoma in situ, and it is diagnosed when the tumor has not yet penetrated the basement membrane or other delimiting structure to invade adjacent tissues. Once the lesion has grown and progressed to the point where it has breached, penetrated, and infiltrated adjacent structures, it is referred to as "invasive" squamous-cell carcinoma. Once a carcinoma becomes invasive, it is able to spread to other organs and cause the formation of a metastasis, or "secondary tumor". 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