Mast cell tumor 1624738 221099878 2008-06-23T01:32:22Z DOI bot 6652755 Citation maintenance. Initiated by [[User:Fconaway|Fconaway]]. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. {{Infobox_Disease | Name = {{PAGENAME}} | Image = | Caption = | DiseasesDB = 34450 | ICD10 = {{ICD10|C|96|2|c|81}}, {{ICD10|D|47|0|d|37}} | ICD9 = {{ICD9|238.5}} | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = derm | eMedicineTopic = 258 | MeshID = D034801 | }} A '''mast cell tumor''' is a type of [[tumor]] consisting of [[mast cell]]s that is found in many species of animals. It is also known as a '''mastocytoma''', which in human medicine can refer to an accumulation or [[nodule (medicine)|nodule]] of [[mast cell]]s that resembles a tumor. A mast cell originates from the [[bone marrow]] and is normally found throughout the [[connective tissue]] of the body. It is a normal component of the [[immune system]] and as it releases [[histamine]] it is associated with [[allergy|allergic reaction]]s. Mast cells also respond to tissue [[physical trauma|trauma]]. Mast cell [[granule]]s contain histamine, [[heparin]], [[platelet-activating factor]], and other substances. Disseminated [[mastocytosis]] is rarely seen in young dogs and cats, while mast cell tumors are a common [[malignant]] tumor of the skin in older dogs and cats. Up to 20 to 25 percent of skin tumors in dogs are mast cell tumors,<ref name=saph>{{cite journal |author=Brière C |title=Use of a reverse saphenous skin flap for the excision of a grade II mast cell tumor on the hind limb of a dog |journal=Can Vet J |volume=43 |issue=8 |pages=620–2 |year=2002 |pmid=12170840}}</ref> with a similar number in cats.<ref name=pathol>{{cite journal |author=Johnson T, Schulman F, Lipscomb T, Yantis L |title=Histopathology and biologic behavior of pleomorphic cutaneous mast cell tumors in fifteen cats |journal=Vet Pathol |volume=39 |issue=4 |pages=452–7 |year=2002 |pmid=12126148 |doi=10.1354/vp.39-4-452}}</ref> [[Image:Mast cell tumor side.JPG|thumb|Mast cell tumor on the side of a dog]] [[Image:Mast cell tumor inner thigh.JPG|thumb|Mast cell tumor on the inner thigh of a dog]] [[Image:Mast cell tumor of the toe.JPG|thumb|Mast cell tumor of the paw]] ==Commonly affected breeds== *[[Boxer (dog)|Boxer]] *[[Bulldog]] *[[Basset Hound]] *[[Weimaraner]] *[[Boston Terrier]] *[[Golden Retriever]] *[[Labrador Retriever]] *[[Beagle]] *[[German Shorthaired Pointer]] *[[Scottish Terrier]]<ref name=Morrison_1998>{{cite book|author=Morrison, Wallace B.|title=Cancer in Dogs and Cats|edition=1st ed.|publisher=Williams and Wilkins|year=1998|id=ISBN 0-683-06105-4}}</ref> *[[Pug]] *[[Rhodesian Ridgeback]]<ref name=Merck>{{cite web | title = Cutaneous Mast Cell Tumors | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/72231.htm | accessdate = 2007-01-27 }}</ref> ==Signs== Mast cell tumors are known amongst veterinary [[oncologist]]s as 'the great pretenders' because their appearance can be varied, from a [[wart]]-like nodule to a soft subcutaneous lump (similar on palpation to a benign [[lipoma]]) to an [[ulcer]]ated skin mass. All lumps should be checked by [[Needle aspiration biopsy|fine needle aspiration]]: palpation or visual inspection is never adequate. Most mast cell tumors are small, raised lumps on the skin. They may be hairless, [[ulcer]]ated, or itchy. They are usually solitary, but in about 6 percent of cases there are multiple mast cell tumors<ref name=Moore>{{cite web | last = Moore | first = Anthony S. | title = Cutaneous Mast Cell Tumors in Dogs | work = Proceedings of the 30th World Congress of the World Small Animal Veterinary Association | date = 2005 | url = http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2005&PID=10953&O=Generic | accessdate = 2006-08-19 }}</ref> (especially in Boxers and Pugs)<ref name=Merck/>. Manipulation of the tumor may result in redness and swelling from release of mast cell granules, also known as [[Darier's sign]], and prolonged local hemorrhage. In rare cases a highly malignant tumor is present, and signs may include loss of appetite, [[vomiting]], [[diarrhea]], and [[anemia]]. The presence of these signs usually indicates [[mastocytosis]], which is the spread of mast cells throughout the body. Release of a large amount of histamine at one time can result in ulceration of the [[stomach]] and [[duodenum]] (present in up to 25 percent of cases)<ref name=Merck/>, or [[disseminated intravascular coagulation]]. When [[metastasis]] does occur, it is usually to the [[liver]], [[spleen]], [[lymph node]]s and [[bone marrow]]. ==Diagnosis== [[Image:Mast cell tumor cytology 2.JPG|thumb|250px|Mast cell tumor cytology]] 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 [[cellular differentiation|differentiated]] mast cells may have few granules and thus difficult to identify. The granules of the mast cell stain blue to dark purple with a [[Romanowsky stain]], and the cells are medium sized.<ref>{{cite web | title = Common Cytology Results | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/150210.htm | accessdate = 2007-01-27 }}</ref> However, a surgical [[biopsy]] is required to find the [[grading (tumors)|grade]] of the tumor. The grade depends on how well the mast cells are differentiated, [[mitosis|mitotic]] activity, location within the skin, invasiveness, and the presence of [[inflammation]] or [[necrosis]].<ref>{{cite journal | last = Vandis | first = Maria | coauthors = Knoll, Joyce S. | title = Cytological examination of a cutaneous mast cell tumor in a boxer | journal = Veterinary Medicine | volume = 102 | issue = 3 | pages = 165–168 | publisher = Advanstar Communications | date = March 2007 }}</ref> *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<ref name=saph/> However, there is a significant amount of discordance between [[veterinary pathologist]]s in assigning grades to mast cell tumors due to imprecise criteria.<ref>{{cite journal |author=Strefezzi R, Xavier J, Catão-Dias J |title=Morphometry of canine cutaneous mast cell tumors |journal=Vet Pathol |volume=40 |issue=3 |pages=268–75 |year=2003 |pmid=12724567 |doi=10.1354/vp.40-3-268}}</ref> The disease is also staged. *Stage I - a single skin tumor with no spread to [[lymph node]]s *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, bone marrow, or with the presence of mast cells in the blood<ref name=Morrison_1998/> [[X-ray]]s, [[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. [[Antihistamine]]s 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-receptor antagonist|H2 blocker]]s such as [[cimetidine]] protect against stomach damage from histamine. [[Vinblastine]] and [[Lomustine|CCNU]] are common chemotherapy agents used to treat mast cell tumors.<ref name=Moore/> Mast cell tumors that are grade I or II that can be completely removed have a good [[prognosis]]. One study showed that about 23 percent of incompletely removed grade II tumors recurred locally.<ref>{{cite journal |author=Séguin B, Besancon M, McCallan J, Dewe L, Tenwolde M, Wong E, Kent M |title=Recurrence rate, clinical outcome, and cellular proliferation indices as prognostic indicators after incomplete surgical excision of cutaneous grade II mast cell tumors: 28 dogs (1994-2002) |journal=J Vet Intern Med |volume=20 |issue=4 |pages=933–40 |year=2006 |pmid=16955819 |doi=10.1892/0891-6640(2006)20[933:RRCOAC]2.0.CO;2}}</ref> 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.<ref name=Sfiligoi>{{cite journal |author=Sfiligoi G, Rassnick K, Scarlett J, Northrup N, Gieger T |title=Outcome of dogs with mast cell tumors in the inguinal or perineal region versus other cutaneous locations: 124 cases (1990-2001) |journal=J Am Vet Med Assoc |volume=226 |issue=8 |pages=1368–74 |year=2005 |pmid=15844431 |doi=10.2460/javma.2005.226.1368}}</ref> 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. Boxers have a better than average prognosis because of the relatively benign behavior of their mast cell tumors.<ref name=Morrison_1998/> Multiple tumors that are treated similarly to solitary tumors do not seem to have a worse prognosis.<ref>{{cite journal |author=Mullins M, Dernell W, Withrow S, Ehrhart E, Thamm D, Lana S |title=Evaluation of prognostic factors associated with outcome in dogs with multiple cutaneous mast cell tumors treated with surgery with and without adjuvant treatment: 54 cases (1998-2004) |journal=J Am Vet Med Assoc |volume=228 |issue=1 |pages=91–5 |year=2006 |pmid=16426175 |doi=10.2460/javma.228.1.91}}</ref> Mast cell tumors do not necessarily follow the histological prognosis. Further prognostic information can be provided by AgNOR stain of histological or cytological specimen. <ref>{{cite journal |author=Scase T, Edwards D, Miller J, Henley W, Smith K, Blunden A, Murphy S |title=Canine mast cell tumors: correlation of apoptosis and proliferation markers with prognosis |journal=J Vet Intern Med |volume=20 |issue=1 |pages=151–8 |year=2006 |pmid=16496935 |doi=10.1892/0891-6640(2006)20[151:CMCTCO]2.0.CO;2}}</ref> Even then there is a risk of unpredictable behaviour. ==Mast cell tumors in cats== Two types of mast cell tumors have been identified in cats, a mast cell type similar to dogs and a [[histiocyte|histiocytic]] type that appear as subcutaneous nodules and may resolve spontaneously. Young [[Siamese (cat)|Siamese cat]]s are at an increased risk for the histiocytic type,<ref name=pathol/> although the mast cell type is the most common in all cats and is considered to be benign when confined to the skin.<ref name=Merck/> Mast cell tumors of the skin are usually located on the head or trunk.<ref>{{cite journal |author=Litster A, Sorenmo K |title=Characterisation of the signalment, clinical and survival characteristics of 41 cats with mast cell neoplasia |journal=J Feline Med Surg |volume=8 |issue=3 |pages=177–83 |year=2006 |pmid=16476559 |doi=10.1016/j.jfms.2005.12.005}}</ref> Gastrointestinal and [[spleen|splenic]] involvement is more common in cats than in dogs; 50 percent of cases in cats primarily involved the spleen or intestines.<ref name=Takahashi>{{cite journal |author=Takahashi T, Kadosawa T, Nagase M, Matsunaga S, Mochizuki M, Nishimura R, Sasaki N |title=Visceral mast cell tumors in dogs: 10 cases (1982-1997) |journal=J Am Vet Med Assoc |volume=216 |issue=2 |pages=222–6 |year=2000 |pmid=10649758 |doi=10.2460/javma.2000.216.222}}</ref> Gastrointestinal mast cell tumors are most commonly found in the [[Muscularis mucosae|muscularis layer]] of the [[small intestine]] but can also be found in the [[large intestine]].<ref>{{cite web | title = Gastrointestinal Neoplasia | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/23307.htm | accessdate = 2007-01-27 }}</ref> It is the third most common intestinal tumor in cats, after [[lymphoma in animals|lymphoma]] and [[adenocarcinoma]].<ref>{{cite journal | last = Moriello | first = Karen A. | title = Clinical Snapshot | journal = Compendium on Continuing Education for the Practicing Veterinarian | volume = 29 | issue = 4 | pages = 204 | publisher = Veterinary Learning Systems | date = April 2007 }}</ref> Diagnosis and treatment are similar to the dog. Cases involving difficult to remove or multiple tumors have responded well to [[strontium-90]] [[radiation therapy|radiotherapy]] as an alternative to surgery.<ref>{{cite journal |author=Turrel J, Farrelly J, Page R, McEntee M |title=Evaluation of strontium 90 irradiation in treatment of cutaneous mast cell tumors in cats: 35 cases (1992-2002) |journal=J Am Vet Med Assoc |volume=228 |issue=6 |pages=898–901 |year=2006 |pmid=16536702 |doi=10.2460/javma.228.6.898}}</ref> The prognosis for solitary skin tumors is good, but guarded for tumors in other organs. Histological grading of tumors has little bearing on prognosis.<ref>{{cite journal |author=Molander-McCrary H, Henry C, Potter K, Tyler J, Buss M |title=Cutaneous mast cell tumors in cats: 32 cases (1991-1994) |journal=J Am Anim Hosp Assoc |volume=34 |issue=4 |pages=281–4 |year=1998 |pmid=9657159}}</ref> ==Mast cell tumors in other animals== Mast cell tumors are an uncommon occurrence in [[horse]]s. They usually occur as benign, solitary masses on the skin of the head, neck, trunks, and legs. Mineralization of the tumor is common.<ref>{{cite journal |author=Cole R, Chesen A, Pool R, Watkins J |title=Imaging diagnosis--equine mast cell tumor |journal=Vet Radiol Ultrasound |volume=48 |issue=1 |pages=32–4 |year=2007 |pmid=17236357 |doi=10.1111/j.1740-8261.2007.00200.x}}</ref> In [[pig]]s and [[cattle]] mast cell tumors are rare. They tend to be solitary and benign in pigs and multiple and malignant in cattle.<ref name=Merck/> Mast cell tumors are found in the skin of cattle most commonly, but these may be metastases from tumors of the [[viscus|viscera]].<ref>{{cite journal |author=Smith B, Phillips L |title=Congenital mastocytomas in a Holstein calf |journal=Can Vet J |volume=42 |issue=8 |pages=635–7 |year=2001 |pmid=11519274}}</ref> Other sites in cattle include the spleen, muscle, gastrointestinal tract, [[omentum]], and uterus.<ref>{{cite journal |author=Ames T, O'Leary T |title=Mastocytoma in a cow: a case report |journal=Can J Comp Med |volume=48 |issue=1 |pages=115–7 |year=1984 |pmid=6424914}}</ref> ==References== {{reflist}} ==External links== *[http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=1600 ''Mast Cell Tumors'' from The Pet Health Library] *[http://www.petcancercenter.org/Cancer_Types_mast_cell_dog.html ''Mast Cell Tumors in Dogs'' from Pet Cancer Center] *[http://www.petcancercenter.org/Cancer_Types_mast_cell_cat.html ''Mast Cell Tumors in Cats'' from Pet Cancer Center] *[http://www.vetspecialists.co.uk/06_Animal_Welfare/Oncology_Facts/Canine_MastCell_Tumour.html ''Canine Mast Cell Tumour'' from Davies Veterinary Specialists] {{Hematological malignancy histology}} [[Category:Dog diseases]] [[Category:Cat diseases]] [[Category:Horse diseases]] [[Category:Swine diseases]] [[Category:Bovine diseases]]