Search results
Results from the WOW.Com Content Network
New and more precisely defined entities include malignant melanotic nerve sheath tumor (formerly known as melanotic schwannoma) and hybrid nerve sheath tumors. [4] [5] The majority of peripheral nerve tumors are benign tumors of the nerve sheath (usually schwannomas); on rare occasions, they are metastatic tumors or originate from the nerve cells.
The symptoms depend on the tumor's location and degree of invasion. For example, tumors in the gastrointestinal tract may cause vomiting, diarrhea, or weight loss. Tumors in the mouth may cause bad breath, difficulty swallowing, or lack of appetite. Tumors arising in the peripheral nerves may cause pain, lameness, or neurological symptoms.
A malignant peripheral nerve sheath tumor (MPNST) is a form of cancer of the connective tissue surrounding peripheral nerves. Given its origin and behavior it is classified as a sarcoma. About half the cases are diagnosed in people with neurofibromatosis; the lifetime risk for an MPNST in patients with neurofibromatosis type 1 is 8–13%. [2]
Each nerve sheath tumor type has a few different associated features on MRI imaging. Neurofibromas and malignant peripheral nerve sheath tumors can be difficult to distinguish from each other and may require additional testing, including PET scans (18 FDG-PET). [1] Image-guided needle biopsies may be performed if there is concern for malignancy ...
Mammary gland tumors are the third common type of cancer in older female cats, with the most common symptom manifesting as a lump in the breast tissue. [3] Domestic short-haired cats and Siamese appear to have a higher incident rates. [10] The tumor is typically firm and nodular, and adheres to the overlying skin. [11]
Malignant melanotic nerve sheath tumor (previously known as melanotic schwannoma) is a rare aggressive peripheral nerve sheath tumor that typically develops in conjunction with spinal or visceral autonomic nerves, consisting uniformly of Schwann cells displaying melanocytic differentiation.
Because soft tissue is relatively elastic, tumors can grow rather large, pushing aside normal tissue, before they are felt or cause any problems. The first noticeable symptom is usually a painless lump or swelling. As the tumor grows, it may cause other symptoms, such as pain or soreness, as it presses against nearby nerves and muscles.
A vaccine-associated sarcoma (VAS) or feline injection-site sarcoma (FISS) is a type of malignant tumor found in cats (and, often, dogs and ferrets) which has been linked to certain vaccines. VAS has become a concern for veterinarians and cat owners alike and has resulted in changes in recommended vaccine protocols.