Historically, hematological malignancies have been most commonly divided by whether the malignancy is mainly located in the blood (leukemia) or in lymph nodes (lymphomas).

However, the influential WHO Classification (published in 2001) placed a greater emphasis on cell lineage.

Relative proportions of hematological malignancies in the United States

A needle aspiration biopsy of the tumor will typically show a large number of mast cells. This is sufficient to make the diagnosis of a mast cell tumor, although poorly differentiated mast cells may have few granules and thus are difficult to identify. The granules of the mast cell stain blue to dark purple with a Romanowsky stain, and the cells are medium-sized. However, a surgical biopsy is required to find the grade of the tumor. The grade depends on how well the mast cells are differentiated, mitotic activity, location within the skin, invasiveness, and the presence of inflammation or necrosis.

- Grade I – well differentiated and mature cells with a low potential for metastasis

- Grade II – intermediately differentiated cells with potential for local invasion and moderate metastatic behavior

- Grade III – undifferentiated, immature cells with a high potential for metastasis

However, there is a significant amount of discordance between veterinary pathologists in assigning grades to mast cell tumors due to imprecise criteria.

The disease is also staged according to the WHO system:

- Stage I - a single skin tumor with no spread to lymph nodes

- Stage II - a single skin tumor with spread to lymph nodes in the surrounding area

- Stage III - multiple skin tumors or a large tumor invading deep to the skin with or without lymph node involvement

- Stage IV – a tumor with metastasis to the spleen, liver, or bone marrow, or with the presence of mast cells in the blood

X-rays, ultrasound, or lymph node, bone marrow, or organ biopsies may be necessary to stage the disease.

Biopsy of affected lymph nodes or organs confirms the diagnosis, although a needle aspiration of an affected lymph node can increase suspicion of the disease. X-rays, ultrasound and bone marrow biopsy reveal other locations of the cancer. There are now a range of blood tests that can be utilised to aid in the diagnosis of lymphoma. Flow cytometry detects antibodies linked to tumour cell surface antigens in fluid samples or cell suspensions. Polymerase chain reaction (PCR) for antigen receptor rearrangements (PARR) identifies circulating tumour cells based on unique genetic sequences. The canine Lymphoma Blood Test (cLBT) measures multiple circulating biomarkers and utilises a complex algorithm to diagnose lymphoma. This test utilises the acute phase proteins (C-Reactive Protein and Haptoglobin). In combination with basic clinical symptoms, it gives in differential diagnosis the sensitivity 83.5% and specificity 77%. The TK canine cancer panel is an indicator of general neoplastic disease. The stage of the disease is important to treatment and prognosis. Certain blood tests have also been shown to be prognostic.

The stage of the disease is important to treatment and prognosis.

- Stage I - only one lymph node or lymphoid tissue in one organ involved.

- Stage II - lymph nodes in only one area of the body involved.

- Stage III - generalized lymph node involvement.

- Stage IV - any of the above with liver or spleen involvement.

- Stage V - any of the above with blood or bone marrow involvement.

Each stage is divided into either "substage a", those without systemic symptoms; or "substage b", those with systemic symptoms such as fever, loss of appetite, weight loss, and fatigue.

For the analysis of a suspected "hematological malignancy", a complete blood count and blood film are essential, as malignant cells can show in characteristic ways on light microscopy. When there is lymphadenopathy, a biopsy from a lymph node is generally undertaken surgically. In general, a bone marrow biopsy is part of the "work up" for the analysis of these diseases. All specimens are examined microscopically to determine the nature of the malignancy. A number of these diseases can now be classified by cytogenetics (AML, CML) or immunophenotyping (lymphoma, myeloma, CLL) of the malignant cells.

Treatment with chemotherapy has been used with some success, particularly using lomustine, prednisone, doxorubicin, and cyclophosphamide. Because of the rapid progression of this aggressive disease, the prognosis is very poor.

Removal of the mast cell tumor through surgery is the treatment of choice. Antihistamines, such as diphenhydramine, are given prior to surgery to protect against the effects of histamine released from the tumor. Wide margins (two to three centimeters) are required because of the tendency for the tumor cells to be spread out around the tumor. If complete removal is not possible due to the size or location, additional treatment, such as radiation therapy or chemotherapy, may be necessary. Prednisone is often used to shrink the remaining tumor portion. H2 blockers, such as cimetidine, protect against stomach damage from histamine. Vinblastine and CCNU are common chemotherapy agents used to treat mast cell tumors.

Toceranib and masitinib, examples of receptor tyrosine kinase inhibitors, are used in the treatment of canine mast cell tumors. Both were recently approved by the U.S. Food and Drug Administration (FDA) as dog-specific anticancer drugs.

Grade I or II mast cell tumors that can be completely removed have a good prognosis. One study showed about 23 percent of incompletely removed grade II tumors recurred locally. Any mast cell tumor found in the gastrointestinal tract, paw, or on the muzzle has a guarded prognosis. Previous beliefs that tumors in the groin or perineum carried a worse prognosis have been discounted. Tumors that have spread to the lymph nodes or other parts of the body have a poor prognosis. Any dog showing symptoms of mastocytosis or with a grade III tumor has a poor prognosis. Dogs of the Boxer breed have a better than average prognosis because of the relatively benign behavior of their mast cell tumors. Multiple tumors that are treated similarly to solitary tumors do not seem to have a worse prognosis.

Mast cell tumors do not necessarily follow the histological prognosis. Further prognostic information can be provided by AgNOR stain of histological or cytological specimen. Even then, there is a risk of unpredictable behavior.

Due to the high risk of recurrence and ensuing problems, close monitoring of dogs undergoing chemotherapy is important. The same is true for dogs that have entered remission and ceased treatment. Monitoring for disease and remission/recurrence is usually performed by palpation of peripheral lymph nodes. This procedure detects gross changes in peripheral lymph nodes. Some of the blood tests used in diagnosing lymphoma also offer greater objectivity and provide an earlier warning of an animal coming out of remission.

Complete cure is rare with lymphoma and treatment tends to be palliative, but long remission times are possible with chemotherapy. With effective protocols, average first remission times are 6 to 8 months. Second remissions are shorter and harder to accomplish. Average survival is 9 to 12 months. The most common treatment is a combination of cyclophosphamide, vincristine, prednisone, L-asparaginase, and doxorubicin. Other chemotherapy drugs such as chlorambucil, lomustine (CCNU), cytosine arabinoside, and mitoxantrone are sometimes used in the treatment of lymphoma by themselves or in substitution for other drugs. In most cases, appropriate treatment protocols cause few side effects, but white blood cell counts must be monitored.

Allogeneic and autologous stem cell transplantations (as is commonly done in humans) have recently been shown to be a possible treatment option for dogs. Most of the basic research on transplantation biology was generated in dogs. Current cure rates using stem cell therapy in dogs approximates that achieved in humans, 40-50%.

When cost is a factor, prednisone used alone can improve the symptoms dramatically, but it does not significantly affect the survival rate. The average survival times of dogs treated with prednisone and untreated dogs are both one to two months. Using prednisone alone can cause the cancer to become resistant to other chemotherapy agents, so it should only be used if more aggressive treatment is not an option.

Isotretinoin can be used to treat cutaneous lymphoma.

Acute mast cell leukemia is extremely aggressive and has a grave prognosis. In most cases, multi-organ failure including bone marrow failure develops over weeks to months. Median survival after diagnosis is only about 6 months.

The disease in the lungs is characterized by enlargement of the tracheobronchial lymph nodes and infiltration of the lungs, sometimes leading to lung lobe consolidation and pleural effusion. Signs and symptoms include cough, loss of appetite, weight loss, anemia, and difficulty breathing. Seizures and rear limb weakness can be seen. Invasion of the bone marrow can cause pancytopenia. Diagnosis requires a biopsy.

Cytochemical properties of the leukemic cells must be typical of mast cell derivation (presence of metachromatic granules staining with alpha-naphthyl chloroacetate esterase, but not with peroxidase). Mast cell tryptase is an enzyme contained in mast cell granules. Mast cell numbers are best estimated by tryptase immunostaining because very poorly granulated cells may stain very weakly if at all for alpha-naphthol chloroacetate esterase.

On X-ray, giant-cell tumors (GCTs) are lytic/lucent lesions that have an epiphyseal location and grow to the articular surface of the involved bone. Radiologically the tumors may show characteristic 'soap bubble' appearance. They are distinguishable from other bony tumors in that GCTs usually have a nonsclerotic and sharply defined border. About 5% of giant-cell tumors metastasize, usually to a lung, which may be benign metastasis, when the diagnosis of giant-cell tumor is suspected, a chest X-ray or computed tomography may be needed. MRI can be used to assess intramedullary and soft tissue extension.

Interdigitating dendritic cell sarcoma is a form of malignant histiocytosis affecting dendritic cells.

It can present in the spleen. It can also present in the duodenum.

Mast cell sarcoma is an extremely aggressive form of sarcoma made up of neoplastic mast cells. A sarcoma is a tumor made of cells from connective tissue. Mast cell sarcoma is an extremely rare tumor. Only 3 cases are reported so far. Prognosis is extremely poor. People with a mast cell sarcoma have no skin lesions, and pathology examination of the tumor shows it to be very malignant with an aggressive growth pattern. Mast cell sarcoma should not be confused with

extracutaneous mastocytoma, a rare benign mast cell tumor without destructive growth. In the cases observed, mast cell sarcoma terminated quickly as mast cell leukemia; one of the most aggressive human cancers.

Current medical treatments result in survival of some longer than 10 years; in part this is because better diagnostic testing means early diagnosis and treatments. Older diagnosis and treatments resulted in published reports of median survival of approximately 5 years from time of diagnosis. Currently, median survival is 6.5 years. In rare instances, WM progresses to multiple myeloma.

The International Prognostic Scoring System for Waldenström’s Macroglobulinemia (IPSSWM) is a predictive model to characterise long-term outcomes. According to the model, factors predicting reduced survival are:

- Age > 65 years

- Hemoglobin ≤ 11.5 g/dL

- Platelet count ≤ 100×10/L

- B2-microglobulin > 3 mg/L

- Serum monoclonal protein concentration > 70 g/L

The risk categories are:

- Low: ≤ 1 adverse variable except age

- Intermediate: 2 adverse characteristics or age > 65 years

- High: > 2 adverse characteristics

Five-year survival rates for these categories are 87%, 68% and 36%, respectively. The corresponding median survival rates are 12, 8, and 3.5 years.

The IPSSWM has been shown to be reliable. It is also applicable to patients on a rituximab-based treatment regimen. An additional predictive factor is elevated serum lactate dehydrogenase (LDH).

The diagnosis of giant-cell tumors is based on biopsy findings. The key histomorphologic feature is, as the name of the entity suggests, (multinucleated) giant cells with up to a hundred nuclei that have prominent nucleoli. Surrounding mononuclear and small multinucleated cells have nuclei similar to those in the giant cells; this distinguishes the lesion from other osteogenic lesions which commonly have (benign) osteoclast-type giant cells. Soap-bubble appearance is a characteristic feature.

Medical imaging techniques such as X-rays, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) are often used in evaluating animals with suspected liver tumors. Ultrasound-guided fine-needle aspiration or needle-core biopsy of liver masses are useful diagnostic tools that are minimally invasive to obtain samples for histopathological analysis.

Diagnosis is by complete blood count (CBC). However, in some cases, a more accurate absolute eosinophil count may be needed. Medical history is taken, with emphasis on travel, allergies and drug use. Specific test for causative conditions are performed, often including chest x-ray, urinalysis, liver and kidney function tests, and serologic tests for parasitic and connective tissue diseases. The stool is often examined for traces of parasites (i.e. eggs, larvae, etc.) though a negative test does not rule out parasitic infection; for example, trichinosis requires a muscle biopsy. Elevated serum B or low white blood cell alkaline phosphatase, or leukocytic abnormalities in a peripheral smear indicates a disorder of myeloproliferation. In cases of idiopathic eosinophilia, the patient is followed for complications. A brief trial of corticosteroids can be diagnostic for allergic causes, as the eosinophilia should resolve with suppression of the immune over-response. Neoplastic disorders are diagnosed through the usual methods, such as bone marrow aspiration and biopsy for the leukemias, MRI/CT to look for solid tumors, and tests for serum LDH and other tumor markers.

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.

In the absence of symptoms, many clinicians will recommend simply monitoring the patient; Waldenström himself stated "let well do" for such patients. These asymptomatic cases are now classified as two successively more pre-malignant phases, IgM monoclonal gammopathy of undetermined significance (i.e. IgM MGUS) and smoldering Waldenström's macroglobulinemia.

But on occasion, the disease can be fatal, as it was to the French president Georges Pompidou, who died in office in 1974. Mohammad Reza Shah Pahlavi, the Shah of Iran, also suffered from Waldenström's macroglobulinemia, which resulted in his ill-fated trip to the United States for therapy in 1979, leading to the Iran hostage crisis.

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.

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.

DSRCT is frequently misdiagnosed. Adult patients should always be referred to a sarcoma specialist. This is an aggressive, rare, fast spreading tumor and both pediatric and adult patients should be treated at a sarcoma center.

There is no standard protocol for the disease; however, recent journals and studies have reported that some patients respond to high-dose (P6 Protocol) chemotherapy, maintenance chemotherapy, debulking operation, cytoreductive surgery, and radiation therapy. Other treatment options include: hematopoietic stem cell transplantation, intensity-modulated radiation Therapy, radiofrequency ablation, stereotactic body radiation therapy, intraperitoneal hyperthermic chemoperfusion, and clinical trials.

Second most common primary anterior mediastinal mass in adults. Most are seen in the anterior compartment and rest are seen in middle compartment. Hodgkin's usually present in 40-50's with nodular sclerosing type (7), and non-Hodgkin's in all age groups. Can also be primary mediastinal B-cell lymphoma with exceptionally good prognosis. Common symptoms include fever, weight loss, night sweats, and compressive symptoms such as pain, dyspnea, wheezing, Superior vena cava syndrome, pleural effusions (10,11). Diagnosis usually by CT showing lobulated mass. Confirmation done by tissue biopsy of accompanying nodes if any, mediastinoscopy, mediastinotomy, or thoracotomy. FNA biopsy is usually not adequate. (12,13,14) Treatment of mediastinal Hodgkin's involves chemotherapy and/or radiation. 5 year survival is now around 75%. (15) Large-cell type may have somewhat better prognosis. Surgery is generally not performed because of invasive nature of tumor.

Of all cancers involving the same class of blood cell, 2% of cases are mediastinal large B cell lymphomas.

JCT often is described as benign, however one case of metastasis has been reported, so its malignant potential is uncertain. In most cases the tumor is encapsulated.

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.