Definitive diagnosis of Merkel cell carcinoma (MCC) requires examination of biopsy tissue. An ideal biopsy specimen is either a punch biopsy or a full-thickness incisional biopsy of the skin including full-thickness dermis and subcutaneous fat. In addition to standard examination under light microscopy, immunohistochemistry (IHC) is also generally required to differentiate MCC from other morphologically similar tumors such as small cell lung cancer, the small cell variant of melanoma, various cutaneous leukemic/lymphoid neoplasms, and Ewing's sarcoma. Similarly, most experts recommend longitudinal imaging of the chest, typically a CT scan, to rule out that the possibility that the skin lesion is a cutaneous metastasis of an underlying small cell carcinoma of the lung.

It is important to exclude a tumor which is directly extending into the ear canal from the parotid salivary gland, especially when dealing with an adenoid cystic or mucoepidermoid carcinoma. This can be eliminated by clinical or imaging studies. Otherwise, the histologic differential diagnosis includes a ceruminous adenoma (a benign ceruminous gland tumor) or a neuroendocrine adenoma of the middle ear (middle ear adenoma).

There are many diagnostic methods that can be used to determine the type of salivary gland tumour and if it is benign or malignant. Examples of diagnostic methods include:

Physical exam and history: An exam of the body to check general signs of health. The head, neck, mouth, and throat will be checked for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.

Endoscopy: A procedure to look at organs and tissues inside the body to check for abnormal areas. For salivary gland cancer, an endoscope is inserted into the mouth to look at the mouth, throat, and larynx. An endoscope is a thin, tube-like instrument with a light and a lens for viewing.

MRI

Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.

Fine needle aspiration (FNA) biopsy: The removal of tissue or fluid using a thin needle. An FNA is the most common type of biopsy used for salivary gland cancer, and has been shown to produce accurate results when differentiating between benign and malignant tumours.

Radiographs: An OPG (orthopantomogram) can be taken to rule out mandibular involvement. A chest radiograph may also be taken to rule out any secondary tumours.

Ultrasound: Ultrasound can be used to initially assess a tumour that is located superficially in either the submandibular or parotid gland. It can distinguish an intrinsic from an extrinsic neoplasm. Ultrasonic images of malignant tumours include ill defined margins.

Carcinomas can be definitively diagnosed through biopsy, including fine-needle aspiration (FNA), core biopsy, or subtotal removal of single node. Microscopic examination by a pathologist is then necessary to identify molecular, cellular, or tissue architectural characteristics of epithelial cells.

Staging of carcinoma refers to the process of combining physical/clinical examination, pathological review of cells and tissues, surgical techniques, laboratory tests, and imaging studies in a logical fashion to obtain information about the size of the neoplasm and the extent of its invasion and metastasis.

Carcinomas are usually staged with Roman numerals. In most classifications, Stage I and Stage II carcinomas are confirmed when the tumor has been found to be small and/or to have spread to local structures only. Stage III carcinomas typically have been found to have spread to regional lymph nodes, tissues, and/or organ structures, while Stage IV tumors have already metastasized through the blood to distant sites, tissues, or organs.

In some types of carcinomas, Stage 0 carcinoma has been used to describe carcinoma "in situ", and occult carcinomas detectable only via examination of sputum for malignant cells (in lung carcinomas).

In more recent staging systems, substages (a, b, c) are becoming more commonly used to better define groups of patients with similar prognosis or treatment options.

Carcinoma stage is the variable that has been most consistently and tightly linked to the prognosis of the malignancy.

The criteria for staging can differ dramatically based upon the organ system in which the tumor arises. For example, the colon and bladder cancer staging system relies on depth of invasion, staging of breast carcinoma is more dependent on the size of the tumor, and in renal carcinoma, staging is based on both the size of the tumor and the depth of the tumor invasion into the renal sinus. Carcinoma of the lung has a more complicated staging system, taking into account a number of size and anatomic variables.

The UICC/AJCC TNM systems are most often used. For some common tumors, however, classical staging methods (such as the Dukes classification for colon cancer) are still used.

The prognosis of EMECL is relatively good, and considerably better than most other forms of NSCLC. The skull and dura are possible sites for metastasis from pulmonary EMC. The MIB-1 index is a predictive marker of malignant potential.

According to the NIH Consensus Conference , if DCIS is allowed to go untreated, the natural course or natural history varies according to the grade of the DCIS. Unless treated, approximately 60 percent of low-grade DCIS lesions will have become invasive at 40 years follow-up. High-grade DCIS lesions that have been inadequately resected and not given radiotherapy have a 50 percent risk of becoming invasive breast cancer within seven years. Approximately half of low-grade DCIS detected at screening will represent overdiagnosis, but overdiagnosis of high-grade DCIS is rare. The natural history of intermediate-grade DCIS is difficult to predict. Approximately one-third of malignant calcification clusters detected at screening mammography already have an invasive focus.

The prognosis of IDC depends, in part, on its histological subtype. Mucinous, papillary, cribriform, and tubular carcinomas have longer survival, and lower recurrence rates. The prognosis of the most common form of IDC, called "IDC Not Otherwise Specified", is intermediate. Finally, some rare forms of breast cancer (e.g., sarcomatoid carcinoma, inflammatory carcinoma) have a poor prognosis. Regardless of the histological subtype, the prognosis of IDC depends also on tumor size, presence of cancer in the lymph nodes, histological grade, presence of cancer in small vessels (vascular invasion), expression of hormone receptors and of oncogenes like HER2/neu.

These parameters can be entered into models that provide a statistical probability of systemic spread. The probability of systemic spread is a key factor in determining whether radiation and chemotherapy are worthwhile. The individual parameters are important also because they can predict how well a cancer will respond to specific chemotherapy agents.

Overall, the 5-year survival rate of invasive ductal carcinoma was approximately 85% in 2003.

EMECL is staged in the same manner as other non-small cell lung carcinomas, based on the TNM (Tumor-Node-Metastasis) staging system.

The first step to diagnosing tonsil carcinoma is to obtain an accurate history from the patient. The physician will also examine the patient for any indicative physical signs. A few tests then, maybe conducted depending on the progress of the disease or if the doctor feels the need for. The tests include:

Fine needle aspiration, blood tests, MRI, x-rays and PET scan.

The basis of deciding the T stage depends on physical examination and imaging of the tumor.

This type of carcinoma is commonly managed by local resection, cryotherapy, topical chemotherapy, and radiotherapy. Multimodal therapy has been shown to improve both visual prognosis and survival.

Mohs micrographic surgery has become the treatment of choice for this form of cancer. When used as the primary treatment modality for sebaceous carcinoma of the eyelid, Mohs surgery is associated with significantly lower local and distant recurrence rates.

This form of cancer is often seen in those who chew tobacco or use snuff orally, so much so that it is sometimes referred to as "Snuff dipper's cancer." Chewing betel nuts is an additional risk factor commonly seen in Taiwan.

a) Surgical resection is mainstay of treatment, whenever possible. If tumor is completely removed, post-operative radiation therapy is typically not needed since acinic cell is considered a low-grade histology. Post-operative radiation therapy for acinic cell carcinoma is used if: 1) margins are positive, 2) incomplete resection, 3) tumor invades beyond gland, 4) positive lymph nodes.

b) Neutron beam radiation

c) Conventional radiation

d) Chemotherapy

LCIS (lobular neoplasia is considered pre-cancerous) is an indicator (marker) identifying women with an increased risk of developing invasive breast cancer. This risk extends more than 20 years. Most of the risk relates to subsequent invasive ductal carcinoma rather than to invasive lobular carcinoma.

While older studies have shown that the increased risk is equal for both breasts, a more recent study suggests that the ipsilateral (same side) breast may be at greater risk.

The 1973 WHO grading system for TCCs (papilloma, G1, G2 or G3) is most commonly used despite being superseded by the 2004 WHO grading (papillary neoplasm of low malignant potential [PNLMP], low grade, and high grade papillary carcinoma).

Tumor size staging and node involvement staging can be combined into a single clinical staging number.

This type of cancer occurs most often in Caucasians between 60 and 80 years of age, and its rate of incidence is about twice as high in males as in females. There are roughly 1,500 new cases of MCC diagnosed each year in the United States, as compared to around 60,000 new cases of melanoma and over 1 million new cases of nonmelanoma skin cancer. MCC is sometimes mistaken for other histological types of cancer, including basal cell carcinoma, squamous cell carcinoma, malignant melanoma, lymphoma, and small cell carcinoma, or as a benign cyst. Researchers believe that exposure to sunlight or ultraviolet light (such as in a tanning bed) may increase the risk of developing this disease. Similar to melanoma, the incidence of MCC in the US is increasing rapidly.

Immunosuppression can profoundly increase the odds of developing Merkel-cell carcinoma. Merkel-cell carcinoma occurs 30 times more often in people with chronic lymphocytic leukemia and 13.4 times more often in people with advanced HIV as compared to the general population; solid organ transplant recipients have a 10-fold increased risk compared to the general population.

Surgical excision or laser therapy are possible treatments. Surgical excision alone was effective for controlling VC, but elective neck dissection was not necessary even in patients in the advanced stages.

Prognosis is good for acinic cell carcinoma of the parotid gland, with five-year survival rates approaching is 90%, and 20-year survival exceeding 50%. Patients with acinic cell carcinomas with high grade transformation (sometimes also called dedifferentiation) have significantly worse survival.

The prognosis of an acinic cell carcinoma originating in the lung is much more guarded than cases of this rare histotype occurring in most other organs, but is still considerably better than for other types of lung cancer.

The differential for OSSN includes pterygium, pingueculum, papilloma, solar keratosis, lipoma, lymphoma, chronic blepharoconjunctivitis, inflammation, melanoma, ocular pannus, pyogenic granuloma, kaposi sarcoma, keratocanthoma, mucoepidermoid carcinoma, pseudoepitheliomatous hyperplasia, and adenocarcinoma. While confocal microscopy can be used for diagnosis, biopsy is considered the standard, especially before treatment with a cytotoxic medication.

The diagnosis of renal medullary carcinoma is typically made after individuals with sickle cell trait present with the typical signs and symptoms outlined above, in combination with radiographic imaging (usually abdominal/pelvic CT scan) studies and ultimately surgical biopsy and pathological examination of the tumor. Findings on radiographic examination are non-specific and can reveal a mass deep within the kidney. Histopathology studies show a distinctive pattern that can be distinguished from other renal tumors.

Wide, radical, complete surgical excision is the treatment of choice, with free surgical margins to achieve the best outcome and lowest chance of recurrence. Radiation is only used for palliation. In general, there is a good prognosis, although approximately 50% of patients die from disease within 3–10 years of presentation.

The following methods are employed in the treatment of basal-cell carcinoma (BCC):

Basal-cell carcinoma is a common skin cancer and occurs mainly in fair-skinned patients with a family history of this cancer. Sunlight is a factor in about two-thirds of these cancers; therefore, doctors recommend sunscreens with at least SPF 30. One-third occur in non-sun-exposed areas; thus, the pathogenesis is more complex than UV exposure as "the" cause.

The use of a chemotherapeutic agent such as 5-Fluorouracil or imiquimod, can prevent development of skin cancer. It is usually recommended to individuals with extensive sun damage, history of multiple skin cancers, or rudimentary forms of cancer (i.e., solar keratosis). It is often repeated every 2 to 3 years to further decrease the risk of skin cancer.

Treatment may include the following:

- Surgery with or without radiation

- Radiotherapy

Fast neutron therapy has been used successfully to treat salivary gland tumors, and has shown to be significantly more effective than photons in studies treating unresectable salivary gland tumors.

- Chemotherapy