Squamous+Cell

A: Asymmetry (melanoma lesion more likely to be asymmetric) B: Border irregularity (melanoma more likely to have irregular borders) C: Color (melanoma more likely to be very dark black or blue and have variation in color than a benign mole which is more often uniform in color and light tan or brown) D: Diameter (mole < 6 mm in diameter usually benign) (most that are 6mm or greater need to be evaluated). In addition to the ABCD’s other signs should be observed.[6] The histologic hallmark of SCC is the presence of keratin or "keratin pearls." These are well-formed desmosome attachments and intracytoplasmic bundles of keratin tonofilaments. The term epidermoid can be substituted for squamous.[7] Conventional cutaneous SCC can be divided into 3 histologic grades based the degree of nuclear atypia and keratinization found. Well-differentiated cutaneous SCC is characterized by more normal-appearing nuclei with abundant cytoplasm and extracellular keratin pearls.[7] In contrast, poorly differentiated cutaneous SCC shows a high degree of nuclear atypia with frequent mitoses, a greater nuclear-cytoplasmic ratio, and less keratinization, and it may be difficult to distinguish from mesenchymal tumors, melanoma, or lymphoma. Moderately differentiated cutaneous SCC shares exhibits features of both well-differentiated and poorly differentiated lesions.[7] See the following images. [7] || I. Intraepidermal tumor only II. Tumor present in but does not fill and expand papillary dermis III. Tumor fills and expands papillary dermis IV. Tumor invades into reticular dermis V. Tumor invades subcutis || High risk features of tumors that are used to distinguish T1 and T2 || [].
 * **Epidemiolgy:** || Of the approximately one million newly diagnosed non melanoma skin cancers diagnosed in the United States in 2005, 20% were squamous cell carcinoma. It is the second most common skin cancer in the US. The incidence has increased over the past 20 years. This is possibly related to higher levels of sun exposure, tanning beds, an increase in the elderly, and improved detection. In addition, geographic location and ethnicity influence the risk. [1] ||
 * **Etiology:** || * UV radiation exposure
 * Tanning bed usage
 * Fair complexion
 * DNA repair failure
 * Iatrogenic immunosuppression
 * Non-iatrogenic immunosuppression
 * Tobacco use
 * Alcohol use
 * Age older than 50 years
 * Familial and genetic predisposition
 * Nutritional status
 * Exposure to industrial products and heavy metals
 * Chronic inflammation and irritation
 * Viruses
 * Exposure to ionizing radiation [2] ||
 * **Signs & Symptoms:** || Although SCC can from anywhere on the body the majority of these tumor sites arise in the heavily exposed area of the body (head, ears, shoulders, face, etc.). The accepted rules of early detection of non-melanoma skin cancers can be summed up in the “ABCD’s”[6]
 * Change in color. (Red, white, blue/black)
 * Change in surface. (scaly, flaky, bleeding or moles that don’t heal)
 * Change in texture. (hard or lumpy moles)
 * Change in surrounding skin. (skin near mole that pigmentation is changing)
 * Change in sensation. (painful or tender mole)
 * Change in previously normal skin. ||
 * **Diagnostic Procedures:** || Self-inspection is the earliest form of detections and if any of the factors from the ABCD or irregular mole observations are noticed than a clinical evaluation should be done.[6]
 * Physical exam focusing on changes in normal skin appearance
 * Notation of (mole, freckle or blemish) size, diameter and symmetry
 * Depth of invasion of tumor must be defined with a “dermatoscope” or other “epiluminescence microscopy” (ELM).
 * Once the diagnosis of SCC has been established and due to rapid growth of this type of cancer the course of action can include.[6]
 * Full physical exam to establish other sites
 * Motor skill assessment to detect brain involvement
 * Chest x-ray for lung involvement
 * Liver function test for liver involvement
 * CBC count
 * Alkaline phosphatase levers and bone scan
 * Biopsy of site
 * Surgical excision or resection
 * Also (PET, CT, MR) if involvement has been established. ||
 * **Histology:** || Pathologic analyses may be completed by a dermatologist or a general pathologist, but they are preferably completed by a dermatopathologist with extensive experience in squamous cell carcinoma (SCC).[7] Most SCCs have a gelatinous surface on gross inspection, which frequently is permeated by fibrovascular cores, giving it a papillomatous appearance.[7]
 * **Lymph node drainage:** || For Lymphatic drainage squamous cell carcinoma is dependent of the location on the initial site findings.[7] ||
 * **Metastatic spread:** || The overall risk of metastatic spread for squamous cell carcinoma skin cancers is 2-6%. However, rates have been as high as 47% for cases with extensive perineural invasion.[7] ||
 * **Grading:** || Depth and thickness are the greatest prognostic indicators along with anatomic location and differentiation. Depth and thickness are rated on anatomic levels called “Clark Levels”. [5]
 * **Staging:** || The American Joint Committee on Cancer’s (AJCC) TNM system is used to stage basal and squamous cell skin cancers. ** T ** = tumor size, location, and spread in to nearby tissues.[3]
 * TX: primary tumor can’t be assessed.
 * TO: no evidence of primary tumor
 * Tis: Carcinoma in situ
 * T1: Tumor is 2cm across or smaller and has only one high risk feature.
 * T2: larger than 2cm across or has 2 or more high risk features.
 * T3: Invades facial bones
 * T4: invades bones of the body or base of skull
 * Thicker than 2mm
 * Invaded in to lower dermis or subcutis
 * Invaded tiny nerves if the skin
 * Originates from the ear or hair-bearing lip
 * Poorly differentiated or undifferentiated under microscope
 * N ** = Nodal involvement
 * NX: nearby nodes can’t be assessed
 * NO: No spread to nearby nodes
 * N1: 1 nearby node on the same side of the body as the primary and 3cm or less across
 * N2a: 1 node same side as primary and between 3 and 6cm across
 * N2b: more than 1 node on the same side as the primary, none larger than 6cm
 * N2c: spread to nodes on the opposite side of the body and none larger than 6cm
 * N3: any node is larger than 6cm across
 * M ** = Metastasis or spread to distant organs
 * M0: no spread to organs
 * M1: spread to organs
 * **Radiation side effects:** || * Erythema of the treated area is the earliest side effect
 * Dermatitis dependent of the dosage and energy used
 * Dry desquamation
 * Moist desquamation
 * Burning and itching symptoms
 * Radiation necrosis(usually in higher fractional doses)[4] ||
 * **Prognosis:** || Although most patients do not die from squamous cell carcinoma, these tumors can cause significant morbidity. overall the 5 year survival rate is >90, however, patients with lymph node involvement have a 25-45% 5 year survival rate. [8] ||
 * **Treatments:** || [[image:uwlmedicaldosimetry2012/squamous_cell_carcinoma_2.jpg]]

Squamous cell carcinomas are treated with surgery, chemotherapy, and radiation therapy. They are given 50-60 Gy of radiation in 15-30 fractions. Small lesions are treated with a 1 cm margin, larger lesions have a 2 cm margin. A bolus is used to give more of a surface dose. [4]

[]. || ||
 * **TD 5/5:** || The TD 5/5 for a skin dose is: [9]
 * **References:** || # Lim JL, Asgari M. Epidemiology and risk factors for cutaneous squamous cell carcinoma. Wolters Kluwer Health. UpToDate. []. Accessed July 2, 2012.
 * 1) Drugs, Diseases & Procedures. Medscape. http://emedicine.medscape.com/article/. Accessed June 27, 2012.
 * 2) Cancer staging/ grading. Available at: []. Accessed on July 2,2012
 * 3) Chao KS, Perez CA, Brady LW. Radiation Oncology: Management Decisions. Philadelphia, PA: Lippincott Williams & Wilkins; 2002
 * 4) Protocol for Examination of Specimens from Patients With Squamous cell Carcinoma of the Skin. Available at: __[|http://www.cap.org]__. Accessed on July 5th, 2012.
 * 5) Washington, Charles, and Dennis Leaver. Principles and Practices of Radiation Therapy.St. Louis,Missouri: Mosby Elsevier, 2010
 * 6) Monroe, M.Head and Neck Cutaneous Squamous Cell Carcinoma Workup.Medscape.July 2012. Available at: [|http://emedicine.medscape.com/article/1965430-workup#aw2aab6b5b8aa]. Accessed on July 5, 2012.
 * 7) Head and neck cutaneous squamous cell carcinoma. Medscape. Available at: [|http://emedicine.medscape.com/article/1965430-overview#aw2aab6b2b6aa]. Accessed on July 2, 2012.
 * 8) Emami B, Lyman J, Brown A, et al. Tolerance of normal tissue to therapeutic irradiation. //Int J Radiat Oncol Biol Phys. // 1991;109-122. ||

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