A subcutaneous mass on the neck of a horse

A 25-year-old Arabian gelding was presented for investigation of a subcutaneous neck mass. Fine-needle aspirates and impression smears revealed mast cells with widely varying degrees of cytoplasmic granulation and scattered eosinophils. Histopathology revealed a poorly circumscribed mass composed of sheets and bundles of mast cells with a large population of eosinophils. The mast cells were separated into numerous lobules by a heavy collagenous stroma, and multifocal collagen necrosis was present. Strong reactivity of the tumor cells for both Giemsa and toluidine blue stains confirmed the diagnosis of a mast cell tumor, and a Luna stain accentuated the eosinophilic infiltrates. Cutaneous mast cell tumors are found in many domestic animals but are uncommonly encountered in horses. Equine cutaneous mast cell tumors are usually benign, and there are no reports of visceral metastasis. Surgical excision is thought to be curative.     

Splenic mast cell tumour and mastocytaemia in a cat: case study and literature review

Case: An 11-year-old female domestic shorthaired cat presenting with clinical signs of depression, anorexia, weight loss, fever, anaemia and a mid-abdominal mass was referred for abdominal ultrasound examination.

Clinical findings: Ultrasonography of the abdomen identified a markedly enlarged spleen. Ultrasound-guided fine- needle aspiration biopsy of the spleen revealed a uniform population of mast cells, 11% of which were observed to have phagocytosed erythrocytes. It is speculated that this may have been a contributing factor in the development of anaemia in this case. Mast cells were detected in a peripheral-blood smear and a diagnosis of systemic mastocytosis (splenic mast cell tumour together with mastocytaemia) was made. This diagnosis was subsequently confirmed by histopathology of the spleen.

Conclusion: Splenectomy and treatment with corticosteroids appears to have resulted in remission of clinical signs and anaemia. A reduction in the concentration of mast cells in the peripheral blood had not occurred 6 weeks post- splenectomy, but was evident by 10 months post-splenectomy.     

Moh’s micrographic surgery for the management of a periocular mast cell tumor in a dog

A 3‐year‐old neutered male boxer dog presented with a 6‐month history of a waxing and waning mass of the left dorsotemporal eyelid margin. Cytology and biopsy confirmed a diagnosis of mast cell neoplasia. Systemic staging of the dog failed to reveal any evidence of metastatic neoplasia. Owing to the location of the tumor within the eyelid margin and the wide surgical margins recommended for excision of mast cell tumors, Mohs micrographic surgery (MMS) was chosen for its potential to conserve tissues while providing intraoperative confirmation the tumor was completely excised. Utilizing MMS horizontal sectioning technique, 100% of the surgical margins were assessed prior to closure of the surgical wound. This represents the first time a comprehensive MMS protocol was used in a veterinary patient under general anesthesia.     

Multicentric mast cell tumors in a horse

Abstract: A 6‐year‐old female Rocky Mountain horse was presented for evaluation of draining tracts and distal limb subcutaneous edema on the left front and left hind limbs that had been present for 2 weeks. Direct smears of fluid collected by fine‐needle aspiration of subcutaneous fluid from both limbs were highly cellular with a predominance of eosinophils accompanied by numerous, moderately atypical, variably granulated mast cells. The cytologic diagnosis was mast cell tumor (MCT) with prominent eosinophilic infiltration with a differential diagnosis of eosinophilic granuloma. Histologic evaluation of surgical biopsies of lesions from both limbs was performed on sections stained with H&E, toluidine blue, and Luna stains. The histologic diagnosis was MCT, and staining with toluidine blue and Luna stains confirmed the presence of mast cells and eosinophils, respectively. In addition, the mast cells strongly expressed CD117. This is the first reported case of cutaneous mast cell neoplasia in a horse in which primary presenting complaints were draining tracts and distal limb subcutaneous edema involving multiple limbs. This case illustrates the utility of staining for CD117 expression in combination with traditional stains, such as toluidine blue and Luna, in differentiating MCTs from other eosinophilic lesions in horses.     

Systemic mastocytosis with subcutaneous hemorrhage and edema in a Greyhound dog: case report and review of diagnostic criteria

Systemic mastocytosis, characterized by infiltration of multiple organs by neoplastic mast cells, is a well-described entity in human medicine with specific criteria for diagnosis, but is ill defined in veterinary literature. Hemostatic disorders are reported in humans affected by systemic mastocytosis but have not been well described in veterinary literature. A 5-y-old, spayed female Greyhound dog had a 1-mo history of progressive ventral cutaneous edema, hemorrhage, and pain. Cytology of an antemortem aspirate from the subcutis of the ventral abdomen was suggestive of mast cell neoplasia, but no discrete mass was present. The dog was euthanized and submitted for autopsy; marked subcutaneous edema and hemorrhage were confirmed. The ventral abdominal panniculus and dermis superficial to the panniculus carnosus were infiltrated by a dense sheet of neoplastic mast cells. The neoplastic cells contained toluidine blue–positive granules and formed aggregates within the bone marrow and several visceral organs, including the liver, spleen, heart, and kidney. Diffuse edema and hemorrhage is an unusual presentation of mast cell tumors in dogs. Antemortem tests, including complete blood count, coagulation profile, and viscoelastic coagulation testing, were suggestive of a primary hemostatic defect. We discuss here the diagnostic criteria used in humans, how these can be applied to veterinary patients, and the limitations of the current diagnostic framework.     

Ultrasonographic findings in abdominal mast cell disease: a retrospective study of 19 patients

A retrospective survey from January 1989 to January 1999 of Tufts University Foster Hospital for Small Animals radiology records of 12 dogs and seven cats with cytologically or histopathologically confirmed abdominal mast cell disease was performed. Ultrasound changes in hepatic mast cell infiltration in dogs included a subjective increase in size, a diffuse increase in echogenicity, and one or more hypoechoic nodules. Ultrasound findings in the affected canine spleen included one or more hypoechoic nodules and a subjective increase in size. Two ultrasonographically unremarkable canine livers and one unremarkable spleen were found to be infiltrated by mast cells. The mast cell-infiltrated feline spleen was subjectively increased in size, mottled, irregular, or contained nodules. The affected lymph nodes in both dogs and cats were hypoechoic or inhomogeneous, subjectively increased in size, and rounded. Gastrointestinal involvement in cats was characterized by a thickened ileocecocolic junction or colon with loss of wall layering. Mast cells were not found in the gastrointestinal tract in any dog. One dog with mast cell infiltrate of the kidneys had multiple hypoechoic nodules in the cortex that distorted the outer contour of the kidney. Although these findings are not specific to the disease in either species, abdominal ultrasound is considered a useful tool for determining the extent of disease in small-animal patients with mast cell tumor if used in conjunction with histopathology or cytology.     

Mast cell and plasma cell collision tumor in the spleen of a dog

A 9‐year‐old spayed female English Mastiff was referred for outpatient ultrasound due to a 3‐week history of weight loss, vomiting, and decreased appetite. Abdominal ultrasound showed multiple splenic masses of varying sizes and serum chemistry panel showed hyperglobulinemia. Cytologic examination of fine‐needle aspirates of the splenic masses indicated a mast cell and plasma cell collision tumor. Results of serum and urine protein electrophoresis and immunofixation indicated the plasma cell neoplasia was producing IgA immunoglobulins.     

Metastatic mast cell tumour in a dog presenting with spinal pain

The clinical, advanced imaging and surgical features of a case of canine extradural mast cell tumour are presented. This rare location has only been reported once before as a primary lesion, although the present case may be a metastatic lesion. Given the frequent occurrence and treatment of cutaneous mast cell tumours in dogs, the finding of spinal metastasis is an important reminder to consider metastatic neoplasia in cases of previously treated cancers presenting with spinal pain.     

Unilateral intraocular mastocytosis and anterior uveitis in a dog with subcutaneous mast cell tumors

A 9‐year‐old male castrated Scottish terrier was referred to the Radiation Oncology Service at the William R. Pritchard Veterinary Medical Teaching Hospital for palliative radiation therapy of an incompletely excised, recurrent subcutaneous mast cell tumor (MCT) located over the right scapula, and surgical removal of a perianal MCT. Three weeks after initial presentation and prior to the fifth radiation treatment, the patient was presented with cloudiness of the left eye of 3–7 days duration. Ophthalmic consultation revealed 3+ aqueous flare with a dependent, swirling component filling approximately one‐third of the anterior chamber. Aqueocentesis was performed under general anesthesia. Cytology revealed mast cells with highly atypical morphology and considered most consistent with neoplasia. The patient died 7 months after pathologic diagnosis of MCT on the right shoulder and 2 months after the cytologic diagnosis of malignant mast cells in the left anterior chamber. To the authors' knowledge, this is the first report of intraocular involvement in a mammal with MCTs, described here as intraocular mastocytosis.     

Mastocytemia in dogs with acute inflammatory diseases

Nineteen dogs were identified that had mastocytemia (mast cells in venous blood samples) not associated with mast cell neoplasia. The first 10 dogs were identified by examination of blood films from dogs with suspected parvovirus enteritis (8), fibrinous pericarditis and pleuritis secondary to thoracic lacerations (1), and renal insufficiency of unknown cause (1). Because of the apparent association with acute enteritis, blood films from 52 suspected canine parvovirus cases were examined retrospectively and 8 mastocytemic dogs were found. An additional 52 canine blood films were randomly selected from the same retrospective time period and 1 mastocytemic dog was found that had pneumothorax, pelvic fractures, and hemorrhagic septic abdominal effusion secondary to renal hemorrhage and traumatized intestines. All mastocytemic dogs had acute inflammatory leukograms the day that mast cells were first detected: neutropenia with toxic neutrophils (4), neutropenia with a left shift (8), total neutrophil count within reference interval but with a left shift (5), or neutrophilia with a left shift (2). All dogs except the renal insufficiency case had circulating toxic neutrophils. Five dogs were mastocytemic on more than 1 day. The pathogenesis of the mastocytemia associated with the acute inflammatory disease was not determined.     

Mast cell tumor invading the cornea in a horse

A 3‐year‐old Marwari mare was presented for evaluation of an irregular, reddish mass protruding from behind the right third eyelid. The mass appeared to arise at the ventral limbal area, involved the perilimbal bulbar conjunctiva and widely extended into corneal tissue. No other ocular or systemic abnormalities were detected at the time of presentation. The mass was surgically removed by lamellar keratectomy, with defocused CO₂ laser used as adjunctive therapy to treat the surgical exposed area and its surroundings. Histopathologic evaluation showed sheets of densely packed, well‐differentiated neoplastic mast cells separated by fibrovascular connective tissue. Nuclear staining for Ki‐67 was performed, and an average of 370 cells were positive per 1000 counted cells. Two months postoperatively, the surgical site was filled with flat fibrovascular and pigmented tissue, while the surrounding cornea was transparent with no superficial vascularization around the fibrotic scar. Thirty‐two months after treatment, no recurrence of the neoplasia was reported.     

Mast cell tumour in the third eyelid of a mare

A 4‐year‐old Missouri Fox Trotter mare was referred to the Veterinary Teaching Hospital, Koret School of Veterinary Medicine with a reddish mass protruding from the third eyelid and adjacent palpebral conjunctiva of the left eye. On ophthalmic examination, the mare showed mild blepharospasm, mild mucopurulent discharge and mild corneal oedema in the left eye. Menace response, pupillary light reflexes and intraocular examination were normal. A rounded, fleshy red ulcerated mass, approximately 3 cm in diameter, expanded the edge of the outer surface of the medial third eyelid and conjunctiva of the ventromedial palpebral region. Physical examination was otherwise unremarkable. Based on history and clinical findings, surgical removal was elected. The tumour was excised and the conjunctiva in the area of tumour treated with cryotherapy. Histological evaluation revealed a mast cell tumour on the third eyelid. Nine months follow‐up revealed no recurrence.     

小鼠胃、小肠和精囊黏膜肥大细胞的组织学观察

取健康小鼠胃、肠管和精囊放入生理盐水中冲洗干净,放入10%中性甲醛固定液中固定、透明、浸蜡、包埋,对胃、肠管和精囊进行连续切片,并用苏木精-伊红和甲苯胺蓝染色。然后,用光学显微镜观察小鼠胃、肠管和精囊的肥大细胞并计数,再用生物统计学方法分析、比较了胃、肠管和精囊肥大细胞的分布规律。结果发现,胃内的肥大细胞最多,小肠较少,而精囊中几乎看不到。胃和小肠内肥大细胞主要分布在血管和腺管周围。     

家兔黏膜免疫器官肥大细胞在巴氏杆菌感染中的特征——组织化学与电镜观察

对5例巴氏杆菌感染家兔的空肠与圆小囊肥大细胞（mast cell，MC）进行了组织化学与电镜的观察，发现在细菌感染导致的病变组织边缘、病变组织内血管附近结缔组织中及变性细胞周围组织的上皮下与黏膜下层都出现了大量甲苯胺蓝（Toluidine Blue，TB）阳性肥大细胞。电镜下，MC有的直接与变性细胞密切接触，有的则和血管内皮紧密相触，在此部位的血管内可见有淋巴细胞贴附填充。MC胞浆内充盈大量的特征性颗粒，有时这些颗粒向细胞表面突出形成边缘空隙，即形成所谓的脱颗粒管道，将颗粒内容物逐渐排除细胞外，遗留空腔。     

奶牛乳腺肥大细胞免疫形态学的增龄性变化

应用改良甲苯胺蓝染色法研究不同年龄奶牛乳腺肥大细胞分布特点的增龄性变化，并用Alcian bluc-safranin染色法对肥大细胞进行细胞化学分型研究。结果：青年奶牛乳腺中肥大细胞数量较少，中年奶牛乳腺中肥大细胞的数量增多，有趣的是，老年奶牛乳腺肥大的数量更多，AB-S染色显示，各年龄奶牛乳腺中只有黏膜型肥大细胞。结果表明：奶牛乳腺肥大细胞数量具有随年龄增长而增加的特点，但肥大细胞的类型没有发生改变。     

The distribution and heterogeneity of mast cells in tongue from five different avian species

This study was conducted with the aim of determining the morphology, distribution and heterogeneity of mast cells in the tongues of seagull (Larus fuscus), common buzzard (Buteo buteo), goose (Anser anser), white stork (Ciconia ciconia) and Gerze rooster. The study used five samples of tongue material from each of the healthy adult avian species. The samples were fixed in 10% neutral‐buffered formalin (NBF) solution, then, after routine tissue follow‐up, the samples blocked with paraplast. Cross‐sections with 5–6 μm of thickness were stained with the 0.5% toluidine blue and alcian blue/safranin O (AB/SO). In all five avian species, it was found that the mast cells were in different sizes and round, oval or spindle‐shaped based on their place of distribution. Mast cell numbers were determined in stained with toluidine blue, examined ×40 objectives in a 1 mm² area. It was observed that mast cell density in subepithelial lamina propria and microscopic papilla was higher in the tongues of all species. Mast cell distribution and heterogeneity varied through the tongue, and there were more mast cells in the dorsal side of the tongue than the ventral side. The highest amount of mast cells was found in the tongue of the Gerze rooster among all five species. In the tongue cross‐sections stained with the combined method of alcian blue/safranin O (AB/SO), the mast cells were stained as AB (+), SO (+) and AB/SO (+) (mixed).     

Histological and immunohistochemical features of cutaneous mast cell tumor in six captive four-toed hedgehogs (Atelerix albiventris)

This report described the histopathological and immunohistochemical features of cutaneous mast cell tumor (MCT) in six hedgehogs. The hedgehogs presented single cutaneous mass with ulcer and crusting. Histologically, the neoplastic lesions were characterized by the proliferation of well-differentiated mast cells (3 cases), and atypical mast cells (3 cases) with one atypical histiocytic morphology. Immunohistochemically, tumor cells were positive for KIT and mast cell tryptase, and were negative for Iba-1. In well-differentiated MCT, all patients were clinically improved and survived more than 365 days after surgical excision, whereas an atypical histiocytic MCT showed aggressive behavior with re-recurrence, and the animal died 115 days after surgery. These findings suggest that, compatible with other animals, well-differentiated MCT has a better prognosis in hedgehogs.     

奶牛发育各期乳腺肥大细胞的组织化学特性研究

本研究旨在对奶牛乳腺肥大细胞的组织化学特点进行研究。对奶牛发育各期乳腺进行取样,应用改良甲苯胺蓝染色法(MTB)和阿尔新蓝—番红鉴别染色法（AB-S）进行染色,观察肥大细胞的组织化学特点和数量变化特点。同时比较了甲苯胺蓝染色时两种固定液固定对乳腺肥大细胞着染的效果。奶牛不同发育时期乳腺肥大细胞只被阿尔新蓝染色,Carnoy氏液固定效果优于中性甲醛（NBF）,MTB的染色效果优于AB-S。奶牛乳腺肥大细胞的数量在泌乳各期和静止期有显著的变化。与静止期相比,泌乳期的乳腺肥大细胞数量明显减少(P＜0.05),分娩后60 d奶牛乳腺肥大细胞的数量最少。奶牛乳腺只存在黏膜型肥大细胞;用Carnoy氏液固定,用MTB法染色可以很好地显示肥大细胞;泌乳期乳腺肥大细胞数量与静止期相比,明显减少。     

RADIATION THERAPY FOR INCOMPLETELY RESECTED CANINE MAST CELL TUMORS

The records of 56 dogs treated with megavoltage radiation for mast cell neoplasia were reviewed to determine the efficacy of this treatment modality. Total radiation dose ranged from 45 to 57 Gray (Gy), dose per fraction ranged from 3.0 to 4.0 Gy, and radiation treatment time ranged from 14–28 days. Median disease free interval (95% CI) was 32.7 (19–70) months. Median disease free interval for dogs older than 7.5 years was 15 (lower limit 7) months as compared to 62 (lower limit 20) for dogs younger than 7.5 years of age (p = 0.006). Median disease free interval for dogs with measurable disease was 12 (lower limit 5) months as compared to 54 (32–70) months for dogs with microscopic disease (p = 0.006). Radiation treatment time was also significantly related to disease free interval. Median disease free interval for dogs treated longer than 22 days was 12 (7–19) months as compared to greater than 50 (lower limit 20) months for dogs treated in 22 or fewer days (p < 0.001). This appeared to be due to more recurrences in dogs treated with 3-per-week fractionation and suggests that tumor proliferation in the interfraction interval may be important. Sex, tumor location, histologic grade, WHO clinical stage, number of radiation fractions, total radiation dose, and dose-per-fraction, as well as the following "yes/no" variables: steroids given, surgery prior to radiation, lymph nodes irradiated, and development of another mast cell tumor did not appear to influence median disease free interval or survival. Data presented herein support megavoltage radiation as an effective treatment for canine mast cell neoplasia, and suggest that disease free interval in dogs treated with daily fractions may be longer than that achieved with alternating day fractions.     

发育各期奶牛乳腺肥大细胞类胰蛋白酶的表达

为了研究奶牛乳腺肥大细胞的组织化学特点和分布特征,对21头发育各期奶牛乳腺进行取样,应用免疫组织化学方法（SP）,观察奶牛乳腺肥大细胞类胰蛋白酶的表达。结果显示,奶牛乳腺肥大细胞表达类胰蛋白酶,肥大细胞数量在各期有显著差异,泌乳期的乳腺肥大细胞数量明显减少（P〈0.01）,分娩后60d奶牛乳腺肥大细胞的数量最少。结果表明,肥大细胞数量随生理周期的改变而改变,静止期奶牛的局部免疫能力增强。