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 metastasisHowever, 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 bloodX-rays, ultrasound, or lymph node, bone marrow, or organ biopsies may be necessary to stage the disease. Treatment and prognosis
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.
Individuals with ADHD are 4x more likely to develop and be diagnosed with an eating disorder (Anorexia, Bulimia, Binge Eating, ARFID) compared to those without ADHD. Individuals with diagnosed eating disorders are 2.6x more likely to have ADHD than those without eating disorders, though these numbers are likely much lower than actual rates, due to limitations with screening and diagnosis in marginalized populations. Trauma
ADHD, trauma, and Adverse Childhood Experiences are also comorbid, which could in part be potentially explained by the similarity in presentation between different diagnoses. The symptoms of ADHD and PTSD can have significant behavioral overlap with ADHD—in particular, motor restlessness, difficulty concentrating, distractibility, irritability/anger, emotional constriction or dysregulation, poor impulse control, and forgetfulness are common in both. This could result in trauma-related disorders or ADHD being mis-identified as the other. Additionally, traumatic events in childhood are a risk factor for ADHD - it can lead to structural brain changes and the development of ADHD behaviors. Finally, the behavioral consequences of ADHD symptoms cause a higher chance of the individual experiencing trauma (and therefore ADHD leads to a concrete diagnosis of a trauma-related disorder). Non-psychiatric
Some non-psychiatric conditions are also comorbidities of ADHD. This includes epilepsy, a neurological condition characterised by recurrent seizures. There are well established associations between ADHD and obesity, asthma  and sleep disorders, and an association with celiac disease. Children with ADHD have a higher risk for migraine headaches, but have no increased risk of tension-type headaches.