80% of cases in the United States are diagnosed by mammography screening.

MASC is currently treated as a low-grade (i.e. Grade 1) carcinoma with an overall favorable prognosis. These cases are treated by complete surgical excision. However, the tumor does have the potential to recur locally and/or spread beyond surgically dissectible margins as well as metastasize to regional lymph nodes and distant tissues, particularly in tumors with histological features indicating a high cell growth rate potential. One study found lymph node metastasis in 5 of 34 MASC patients at initial surgery for the disease; these cases, when evidencing no further spread of disease, may be treated with radiation therapy. The treatment of cases with disease spreading beyond regional lymph nodes has been variable, ranging from simple excision to radical resections accompanied by adjuvant radiotherapy and/or chemotherapy, depending on the location of disease. Mean disease-free survival for MASC patients has been reported to be 92 months in one study.

The tyrosine kinase activity of NTRK3 as well as the ETV6-NTRK3 protein is inhibited by certain tyrosine kinase inhibitory drugs such as Entrectinib and LOXO-101; this offers a potential medical intervention method using these drugs to treat aggressive MASC disease. Indeed, one patient with extensive head and neck MASC disease obtained an 89% fall in tumor size when treated with entrectinib. This suppression lasted only 7 months due to the tumor's acquirement of a mutation in the "ETV6-NTRK3" gene. The newly mutated gene encoded an entrectinib-reisistant "ETV6-NTRK3" protein. Treatment of aggressive forms of MASC with NTRK3-inhibiting tyrosine kinase inhibiting drugs, perhaps with switching to another type of tyrosine kinase inhibitor drug if the tumor acquires resistance to the initial drug, is under study.STARTRK-2

While the histopathologic features and molecular features of ADH are that of (low-grade) DCIS, its clinical behaviour, unlike low-grade DCIS, is substantially better; thus, the more aggressive treatment for DCIS is not justified. In oncology in general, it is observed that tumour size is often strongly predictive of the clinical behaviour and, thus, a number of cancers (e.g. adenocarcinoma of the lung, papillary renal cell carcinoma) are defined, in part, on the basis of a minimum size.

Appearance and location of the tumor is enough to identify it as a mammary tumor. Biopsy will give type and invasiveness of the tumor. In addition, newer studies showed that certain gene expression patterns are associated with malignant behaviour of canine mammary tumors.

Surgical removal is the treatment of choice, but chest x-rays should be taken first to rule out metastasis. Removal should be with wide margins to prevent recurrence, taking the whole mammary gland if necessary. Because 40 to 50 percent of dog mammary tumors have estrogen receptors, spaying is recommended by many veterinarians. A recent study showed a better prognosis in dogs that are spayed at the time of surgery or that had been recently spayed. However, several other studies found no improvement of disease outcome when spaying was performed after the tumor had developed. Chemotherapy is rarely used.

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.

Cancer screening uses medical tests to detect disease in large groups of people who have no symptoms. For individuals with high risk of developing lung cancer, computed tomography (CT) screening can detect cancer and give a person options to respond to it in a way that prolongs life. This form of screening reduces the chance of death from lung cancer by an absolute amount of 0.3% (relative amount of 20%). High risk people are those age 55–74 who have smoked equivalent amount of a pack of cigarettes daily for 30 years including time within the past 15 years.

CT screening is associated with a high rate of falsely positive tests which may result in unneeded treatment. For each true positive scan there are about 19 falsely positives scans. Other concerns include radiation exposure and the cost of testing along with follow up. Research has not found two other available tests—sputum cytology or chest radiograph (CXR) screening tests—to have any benefit.

The United States Preventive Services Task Force (USPSTF) recommends yearly screening using low-dose computed tomography in those who have a total smoking history of 30 pack-years and are between 55 and 80 years old until a person has not been smoking for more than 15 years. Screening should not be done in those with other health problems that would make treatment of lung cancer if found not an option. The English National Health Service was in 2014 re-examining the evidence for screening.

As soon as a tumor is detected, diagnosing the type of cancer remains a primary objective, as it helps determine the best possible treatment by the analysis of the structure of the tumor and cancer cells.

It is diagnosed based on tissue, e.g. a biopsy. Histomorphologically, it has architectural changes seen in low-grade ductal carcinoma in situ (DCIS), e.g. cribriform architecture, and like low-grade DCIS has minimal nuclear atypia and no necrosis.

CT-scans, MRIs, sonography (ultrasound), and endoscopy (including endoscopic ultrasound) are common diagnostic tools. CT-scans using contrast medium can detect 95 percent of tumors over 3 cm in size, but generally not tumors under 1 cm.

Advances in nuclear medicine imaging, also known as molecular imaging, has improved diagnostic and treatment paradigms in patients with neuroendocrine tumors. This is because of its ability to not only identify sites of disease but also characterize them. Neuronedocrine tumours express somatostatin receptors providing a unique target for imaging. Octreotide is a synthetic modifications of somatostatin with a longer half-life. OctreoScan, also called somatostatin receptor scintigraphy (SRS or SSRS), utilizes intravenously administered octreotide that is chemically bound to a radioactive substance, often indium-111, to detect larger lesions with tumor cells that are avid for octreotide.

Somatostatin receptor imaging can now be performed with positron emission tomography (PET) which offers higher resolution, three-dimensional and more rapid imaging. Gallium-68 receptor PET-CT is much more accurate than an OctreoScan.

Imaging with fluorine-18 fluorodeoxyglucose (FDG) PET may be valuable to image some neuroendocrine tumors. This scan is performed by injected radioactive sugar intravenously. Tumors that grow more quickly use more sugar. Using this scan, the aggressiveness of the tumor can be assessed.

The combination of somatostatin receptor and FDG PET imaging is able to quantify somatostatin receptor cell surface (SSTR) expression and glycolytic metabolism, respectively. The ability to perform this as a whole body study is highlighting the limitations of relying on histopathology obtained from a single site. This is enabling better selection of the most appropriate therapy for an individual patient.

Hürthle cell adenomas are most likely diagnosed much more frequently than Hürthle cell carcinomas. The female to male ratio for Hurthle cell adenomas is 8:1, while the ratio is 2:1 for the malignant version. Hürthle cell cancer tends to occur in older patients. The median age at diagnosis for Hürthle cell carcinomas is approximately 61 years old. Typically a painless thyroid mass is found in patients with this type of cancer. As expected, patients with carcinoma usually present larger tumors than patients with adenoma. Rarely, the cancer can spread to the lymph nodes. On few occasions, patients with Hürthle cell carcinoma have distant metastases in the lungs or surrounding bones. Hürthle cell neoplasms are somewhat difficult to differentiate between being benign or malignant. Since the size and growth pattern of the tumor cannot be used to determine malignancy, although larger tumors have higher incidence of malignancy, Hürthle cell adenomas and carcinomas have to be separated by the presence, in the case of carcinomas, or absence, in the case of adenomas, of both capsular invasion and vascular invasion. Tumors displaying only capsular invasion tend to behave less aggressively than those with vascular invasion. Hürthle cell carcinomas are characterized as either minimally invasive or widely invasive tumors. While the minimally invasive or encapsulated carcinoma is fully surrounded by a fibrous capsule, the widely invasive carcinoma shows extensive area of both capsular and vascular invasion with the leftover capsule typically difficult to identify. Classification is important since widely invasive tumors can have outcomes with a 55% mortality rate.

A non-minimally invasive Hürthle cell carcinoma is typically treated by a total thyroidectomy followed by radioactive iodine therapy. A Hürthle cell adenoma or a minimally invasive tumor can be treated by a thyroid lobectomy, although some surgeons will perform a total thyroidectomy to prevent the tumor from reappearing and metastasizing.

A modified radical neck dissection may be performed for clinically positive lymph nodes.

Mammary analogue secretory carcinoma occurs somewhat more commonly in men (male to female ratio of <1.5:1.0). Patients with this disease have a mean age of 46 years although ~12% of cases occur in pediatric patients. Individuals typically present with symptomless tumors in the [[parotid|parotid salivary gland]] (68%), [[Oral mucosa#classification|buccal mucosa salivary glands]] (9%), [[Submandibular gland|submandibular salivary gland]] (8%) or in the small salivary glands of the lower lip (5%), upper lip (4%), and [[hard palate]] (4%). [[Histologically]], these tumors are described as have a morphology similar to secretory breast carcinoma; they typically having one or more of the following histological patterns: microcystic, papillary-cystic, follicular, and/or solid lobular. Other histological features of these tissues include: the presence of eosinophilic secretions as detected by staining strongly for [[eosin Y]]; positive staining with [[periodic acid-Schiff stain]] (often after [[diastase]]); the presence of vesicular oval nuclei with a single small but prominent [[nucleolus]]; and the absence of basophilic [[Haematoxylin]] or [[zymogen]] granules (i.e. vesicles that store enzymes near the cell's plasma membrane).

The cited histology features are insufficient to distinguish MASC from other [[Salivary gland neoplasm]]s such as [[acinic cell carcinoma]], low-grade cribriform cystadenocarcinoma, and adenocarcinoma not otherwise specified. MASC can be distinguished from these and other histologically similar tumors by either tissue identification of a) the "ETV6-NTRK3" fusion gene using [[Fluorescence in situ hybridization]] or [[reverse transcription polymerase chain reaction]] gene detection methods or b) a specific pattern of marker proteins as registered using specific antibody-based detection methods, i.e. MASC tissue should have detectable [[S100 protein|S100]] (a family of calcium binding proteins), [[Mammaglobin]] (a breast cancer marker, Keratin 7 (an intermediate filament found in epithelial cells), GATA3 (a transcription factor and breast cancer biomarker), SOX10 (a transcription factor important in neural crest origin cells and development of the peripheral nervous system), and STAT5A (a transcription factor) but lack antibody-detectable TP63 (a transcription factor in the same family as p53) and Anoctamin-1 (a voltage sensitive calcium activated chloride channel).

The diagnosis is based on examination under a microscope, by a pathologist. Radiologic findings may be suggestive, as these tumors are well-circumscribed and devoid of calcifications.

Because DCIS is normally found early and it is treated or managed, it is difficult to say what occurs if left untreated. About 2% of women who are diagnosed with this condition and treated died within 10 years. Biomarkers can identify which women who were initially diagnosed with DCIS are at high or low risk of subsequent invasive cancer.

Treatments of cancer in cats usually consists of diagnosis and observation of the tumor to determine its type and size, the development of a treatment plan, the associated goals on the part of the treatment methods, and the regular evaluation of the overall health of the pet.

Triple-negative breast cancer accounts for approximately 15%-25% of all breast cancer cases. The overall proportion of TNBC is very similar in all age groups. Younger women have a higher rate of basal or BRCA related TNBC while older women have a higher proportion of apocrine, normal-like and rare subtypes including neuroendocrine TNBC.

Among younger women, African American and Hispanic women have a higher risk of TNBC, with African Americans facing worse prognosis than other ethnic groups.

In 2009, a case-control study of 187 triple-negative breast cancer patients described a 2.5 increased risk for triple-negative breast cancer in women who used oral contraceptives (OCs) for more than one year compared to women who used OCs for less than one year or never. The increased risk for triple-negative breast cancer was 4.2 among women 40 years of age or younger who used OCs for more than one year, while there was no increased risk for women between the ages of 41 and 45. Also, as duration of OC use increased, triple-negative breast cancer risk increased.

Mammary tumors are the third most common neoplasia in cats, following lymphoid and skin cancers. The incidence of mammary tumors in cats is reduced by 91 percent in cats spayed prior to six months of age and by 86 percent in cats spayed prior to one year, according to one study. Siamese cats and Japanese breeds seem to have increased risk, and obesity also appears to be a factor in tumor development. Malignant tumors make up 80 to 96 percent of mammary tumors in cats, almost all adenocarcinomas. Male cats may also develop mammary adenocarcinoma, albeit rarely, and the clinical course is similar to female cats. As in dogs, tumor size is an important prognostic factor, although for tumors less than three centimeters the individual size is less predictive. According to one study, cats with tumors less than three cm had an average survival time of 21 months, and cats with tumors greater than three cm had an average survival of 12 months. About 10 percent of cat mammary tumors have estrogen receptors, so spaying at the time of surgery has little effect on recurrence or survival time. Metastasis tends to be to the lungs and lymph nodes, and rarely to bone. Diagnosis and treatment is similar to the dog. There is a better prognosis with bilateral radical surgery (removing the both mammary chains) than with more conservative surgery. Doxorubicin has shown some promise in treatment.

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

Smoking prevention and smoking cessation are effective ways of preventing the development of lung cancer.

Based on a survey of >800, surgical removal of the entire involved kidney plus the peri-renal fat appeared curative for the majority of all types of mesoblastic nephroma; the patient overall survival rate was 94%. Of the 4% of non-survivors, half were due to surgical or chemotherapeutic treatments. Another 4% of these patients suffered relapses, primarily in the local area of surgery rare cases of relapse due to lung or bone metastasis.. About 60% of these recurrent cases had a complete remission following further treatment. Recurrent disease was treated with a second surgery, radiation, and/or chemotherapy that often vincristine and actinomycin treatment. Removal of the entire afflicted kidney plus the peri-renal fat appears critical to avoiding local recurrences. In general, patients who were older than 3 months of age at diagnosis or had the cellular form of the disease, stage III disease, or involvement of renal lymph nodes had a higher recurrence rate. Among patients with these risk factors, only those with lymph node involvement are recommended for further therapy.

It has been suggested that mesoblastic nephroma patients with lymph node involvement or recurrent disease might benefit by adding the ALK inhibitor, crizotinib, or a tyrosine kinase inhibitor, either larotrectinib or entrectinib, to surgical, radiation, and/or chemotherapy treatment regimens. These drugs inhibit NTRK3's tyrosine kinase activity. Crizotinib has proven useful in treating certain cases of acute lymphoblastic leukemia that are associated with the "ETV6-NTRK3" fusion gene while larotrectinib and entrectinib have been useful in treating various cancers (e.g. a metastatic sarcoma, papillary thyroid cancer, non-small-cell lung carcinoma, gastrointestinal stromal tumor, mammary analog secretory carcinoma, and colorectal cancer) that are driven by mutated, overly active tyrosine kinases. Relevant to this issue, a 16-month-old girl with infantile fibrosarcoma harboring the "ETV6–NTRK3" fusion gene was successfully trated with larotrectinib. The success of these drugs, howwever, will likely depend on the relative malignancy-promoting roles of ETV6-NTRK3 protein's tyrosine kinase activity, the lose of ETV6-related transcription activity accompanying formation of ETV6-NTRK3 protein, and the various trisomy chromosomes that populate mesoblastic nephroma.

Symptoms from secreted hormones may prompt measurement of the corresponding hormones in the blood or their associated urinary products, for initial diagnosis or to assess the interval change in the tumor. Secretory activity of the tumor cells is sometimes dissimilar to the tissue immunoreactivity to particular hormones.

Given the diverse secretory activity of NETs there are many other potential markers, but a limited panel is usually sufficient for clinical purposes. Aside from the hormones of secretory tumors, the most important markers are:

- chromogranin A (CgA), present in 99% of metastatic carcinoid tumors

- urine 5-hydroxyindoleacetic acid (5-HIAA)

- neuron-specific enolase (NSE, gamma-gamma dimer)

- synaptophysin (P38)

Newer markers include N-terminally truncated variant of Hsp70 is present in NETs but absent in normal pancreatic islets. High levels of CDX2, a homeobox gene product essential for intestinal development and differentiation, are seen in intestinal NETs. Neuroendocrine secretory protein-55, a member of the chromogranin family, is seen in pancreatic endocrine tumors but not intestinal NETs.

Hürthle cell adenoma is the benign analogue of Hürthle cell carcinoma. This adenoma is extremely rare; when it occurs, it usually occurs in women. Often the adenoma is harmless but is removed after detection because its future course cannot be trusted. This mass can be detected and removed before transformation and metastasis. The tumor is often detected by imaging such as ultrasound. The location and size of the tumor may cause pressure and pain to the patient. But often the tumor goes undetected. After detection, the mass is tested using an invasive fine-needle aspiration biopsy.

Myofibroblastoma of the breast, first described by Wargotz et al. {Am J Surg Pathol. 1987 Jul;11(7):493-502} consist of bland spindle cells arranged in fascicles with interspersed thick bundles of collagen. They typically stain with CD34 and desmin.

In extra-mammary sites the tumour is known as a "mammary-type myofibroblastoma", and may immunohistochemically and histomorphologically overlap with spindle cell lipoma.

Diagnosis of mesoblastic nephroma and its particular type (i.e. classic, mixed, or cellular) is made by histological examination of tissues obtained at surgery. Besides its histological appearance, various features of this disease aid in making a differential diagnosis that distinguish it from the following childhood neoplasms:

- Wilm's tumor is the most common childhood kidney neoplasm, representing some 85% of cases. Unlike mesoblastic nephroma, 3 years of age. Bilateral kidney tumors, concurrent birth defects, and/or metastatic disease at presentation favor a diagnosis of Wilm's tumor.

- congenital infantile sarcoma is a rare aggressive sarcoma typically presenting in the lower extremities, head, or neck of infants during their first year of life. The histology, association with the "ETV6-NRTK3" fusion gene along with certain chromosome trisomies, and the distribution of markers for cell type (i.e. cyclin D1 and Beta-catenin) within this tumor are the same as those found in cellular mesoblastic nephroma. Mesoblastic nephroma and congenital infantile sarcoma appear to be the same diseases with mesoblastic lymphoma originating in the kidney and congenital infantile sarcoma originating in non-renal tissues.

- Rhabdoid tumor, which accounts for 5-510% of childhood kidney neoplasms, occurs predominantly in children from 1 to 2 years of age. Unlike mesoblastic nephroma, rhabdoid tumors may present with tumors in other tissues including in ~13% of cases, the brain. Rhabdoid tumors have a distinctive histology and abnormalities (i.e. loss of heterozygosity, single nucleotide polymorphism, and deletions) in chromosome 22.

- Clear cell sarcoma of the kidney, which is responsible for 5-10% of childhood pediatric tumors, occurs predominantly in children from 2 to 3 years of age. Unlike meoblastic nephorma, clear cell sarcoma of the kidney presents with metastasis, particularly to bone, in 5-6% of cases; it histology is diverse and has been mistaken for mesoblastic nephroma. One chromosomal translocations t,(10;17)(q22;p13), has been repeatedly reported to be associated with clear cell sarcoma of the kidney.

- Infantile myofibromatosis is a fibrous tumor of infancy and childhood most commonly presenting during the first 2 years of life as a single subcutaneous nodule of the head and neck region or less commonly as multiple lesions of skin, muscle, bone, and in ~33% of these latter cases, visceral organs. All of these lesions have an excellent prognosis and can regress spontaneously except for those in which there is visceral involvement where the prognosis is poor. While infantile myofibromatosis and classic mesoblastic nephroma have been suggested to be the same diseases because of their very similar histology, studies on the distribution of cell-type markers (i.e. cyclin D1 and Beta-catenin) indicate that they have different cellular origins.

For localization of both primary lesions and metastasis, the initial imaging method is Octreoscan, where indium-111 labelled somatostatin analogues (octreotide) are used in scintigraphy for detecting tumors expressing somatostatin receptors. Median detection rates with octreoscan are about 89%, in contrast to other imaging techniques such as CT scan and MRI with detection rates of about 80%. Gallium-68 labelled somatostatin analogues such as Ga-DOTA-Octreotate (DOTATATE), performed on a PET/CT scanner is superior to conventional Octreoscan.

Usually, on a CT scan, a spider-like/crab-like change is visible in the mesentery due to the fibrosis from the release of serotonin. F-FDG PET/CT, which evaluate for increased metabolism of glucose, may also aid in localizing the carcinoid lesion or evaluating for metastases. Chromogranin A and platelets serotonin are increased.