1. Submitted to:- Dr. D.J. Ghodasara
Associate Professor,
Dept. of vet. Pathology, Anand
Submitted by:- Undhad Vishal
M.V.Sc. Scholar
Dept. of vet. Pathology
2. Mast cell
Mast cell or mastocyte is a normal component of connective
tissue
Mast cell are quite pleomorphic & nucleus are round or
ovoid & basophilic granules
Cytoplasmic basophilic granules physiological active & two
components secretes
1. Histamine
2. Heparin
4. Mastocytoma/Mastoma in Dog
Mastocytoma is benign tumor of tissue mast cells
German “mast” means fattend or stuffed
“cyte” comes from Greek “kytos” means hollow cell
Etiology
Genetic predispose
golden/red coat color
Chronic immune over-stimulation that occurs in dogs with
allergies or other inflammatory conditions.
There may be environmental factors, viruses or other
undetermined contributors.
Middle age to older dogs are more likely to develop MCT's
5. Incidence
6% of all tumors & 13% of skin tumors in dog
Age:- 8 years
Breed:- Boxer & Pug more common
Sex:- Both sex same incidence
Clinical characteristics
Gastric & duodenal ulcer
Focal glomarulonephritis
Defect in immune response
Defective blood coagulation
6. Sites
Hindquarter are most common (thigh, groin, scrotum)
Gross morphology
1 to 10 cm diameter
Tumor present in dermis
Cut surface is grayish white
Some time well capsulated grossly
7. FIGURE 1. A large pedunculated cutaneous mast cell tumor on a mixed-breed female dog.
FIGURE 2. female Shar-Peis at left hindlimb more aggressive and invasive mast cell
tumors with invole mammary tissues.
FIGURE 3. A hyperpigmented raised lesion involving the left lateral thigh region.
FIGURE 4. A raised erythematous mucocutaneous lesion involving the preputial orifice on
a castrated male pug.
8. A large and invasive mast cell
tumor involving the left tarsus in
a female Labrador
Mast cell tumor on the hock of a
6-year-old boxer
9. Mast cell tumor on left hind
limb of a dog
Large Mast cell tumor on the
right fore limb of a dog
13. Preputial mast cell tumor with
peritumoral edema, bruising and
erythema.
Muzzle mast cell tumor.
14. Grade
I One tumor confined to the dermis without
regional lymph node involvement
II One tumor confined to the dermis with regional
lymph node involvement
III Multiple dermal tumors or large infiltrating tumor
with or without regional lymph node involvement
IV Any tumor with distant metastases or recurrence
with metastases
15. Cell
characters
Mature Intermediate Anaplastic
Cell shape Round to avoid Round to avoid Pleomorphic
Cell size Uniform Vary Vary
Cytoplasmic
border
Well defined Indistinct Indistinct
Nuclei Uniformly
spherical
Large, slight
vesicular
Large, vesicular &
irregular
Mitotic figures Rare Present Numerous
Cell arrangement Loosely in cord or
nest
Cord Large sheets
16. Presents of eosinophiles due to some immunological
reaction
Focal area of collagen degeneration are present
Vascular lesion like hyalinization & fibrinoid degeneration
of small arterioles
In 10% cases focal accumulation of lymphocyte & plasma
cells
Hematology
Increase serum gamma globulin
Rarely circulating mast cells
17. Growth & metastasis
Least potentially malignant
Correlation between degree of maturity of tumor &
eventual dissemination of neoplastic mast cells
Internal dissemination of malignant tumor in following
organs regional lymph nodes, spleen, liver, kidneys,
lungs & heart
Prognosis
It is estimated that 50% of surgically removed mast cell
tumors will re-grow in the same area.
Prognosis is variable and depends on many factors
including tumor location, histological grade and clinical
stage
18. Jejunum of dog. Tumor cells are diffusely invading from the mucosal cell
layer to the serosa. Mucosal ulceration is visible with tumor cell
infiltration. HE.
19. Stomach of dog Slight pleomorphic tumor cells include round to ovoid
nuclei with some pleomorphism. Numerous mitotic figures are visible
(arrows). HE.
20. Monotonous population of mast cells with centrally located hyperchromatic
nuclei and few discernable cytoplasmic granules. (HE, 10X)
21. Boxer:-Mast cell tumor, well differentiated, Wright-Leishman stain. Well
differentiated mast cells have numerous, purple, cytoplasmic granules that
partially obscure nuclear morphology.
22. Cutaneous mast cell tumor (well differentiated), dog, Wright-Leishman
stain. The mast cells have numerous purple granules that partially
obscure nuclear morphology
23. Well differentiated mast cells, cutaneous neoplasm, dog, Wright-Leishman
stain. The neoplastic cells are of relatively uniform size and appearance with
numerous fine purple granules.
24. Well differentiated cutaneous mast cell tumor, dog, hematoxylin & eosin
stain. The mast cells have a relatively uniform appearance with heavy
cytoplasmic granulation.
26. Well differentiated cutaneous mast cell tumor, dog, AgNOR stain. The mast
cells have 1-2 AgNORs per cell with an overall score of 1.8. The potential
for metastasis is low.
27. Intermediate differentiation, cutaneous mast cell tumor, dog, AgNOR stain.
The mast cells have 1-7 AgNORs per cell with an overall score of 3.19. The
potential for metastasis is very high.
28. Intermediate differentiation of mast cells, cutaneous neoplasm, dog,
Wright-Leishman stain. The mast cells are large with pleomorphic
cytoplasmic granulation that varies in size and abundance.
29. Poorly differentiated mast cells, cutaneous neoplasm, dog, Wright-
Leishman stain. The mast cell (left) is large and has sparse cytoplasmic
granulation.
30. Boxer:-Mast cell tumor, poorly differentiated, Wright-Leishman stain.
The cytoplasm contains fine but sparse purple granules. A few eosinophils
also are present.
33. Mastocytoma in cat
Two forms:-
1. Cutaneous/skin MCT
2. Histiocytic/visceral MCT
Incidence
Second most common skin tumor (20% of all skin tumors)
Age:- 10 years
Breed:- Siamese cats
Sex:- Male>Female
Sites & gross morphology
Head & neck region more common
Two type cutaneous growths:-
1. Firm
2. Diffuse
34. Multiple mast cell tumors in
the skin of a cat with the
visceral form of mast cell
tumor disease
Multiple mast cell tumors all
over their body
35. Histologic features
Same to dog
Some confusion between mastocytoma & eosinophilic
granuloma complex
Skin & oral cavity diffuse infiltration of eosinophiles & some
extent mast cells in some lesions is called as eosinophilic
granuloma complex
Growth & metastasis
Potentially malignant than dog
50% primary cutaneous mastocytoma involvement of
regional lymph node & liver, spleen & other visceral organs
36. Haired skin of cat:- Endocytosis of erythrocytes
by neoplastic mast cells
37. Lymph node, cat, Wright-Leishman stain. Metastatic mast cells exhibit
anisocytosis and anisokaryosis with a variable degree of fine
metachromatic granulation.
38. Mastocytoma of horse
Classification & incidence
Two distinct form
1. Single cutaneous nodule
2. Disseminated multiple focal mast cell lesion in skin
Age:- 7years
Sex:- Male > Female
Breed:- No predispose
Site & gross morphology
Any where in body but more in head
2 to 20 cm diameter
Tumor confined to skin
Surface normal appearance, hairless or ulcerated
39. Histological features
Variable sized aggregates of well differentiated mast cells
Mitotic figures are rare
Mature eosinophiles are local or diffuse accumulation
Characteristic feature is focal area of necrosis contained
eosinophiles & necrotic debris
Etiology, transmission & metastasis
Unknown
Onchocerca spp. microfilariae
No transmission occurs
Metastasis not reported
40. Mastocytoma of cattle, Sheep & pig
Cattle
3% Of all cutaneous & subcutaneous tumors
No any age, breed & sex predilection
1 to 10 cm diameter
Aggregates of mast cell in regional lymph node, spleen,
liver, lungs, heart & kidneys
Also occurs in internal organs ( omentum, abomasum,
tongue) without cutaneous involvement
Microscopically similar to other spp.
Pig
Age:- 6 to 18 month
Limited to skin single or multiple
No metastasis
Sheep
Vary little information regarding mastocytoma
41. Mast cell leukemia/Mstosarcoma
Primarily in cat with involvement of bone marrow, blood &
spleen
Age:- >8years
Sex:- Male>Female
Splenomegaly (splenicmastocytosis), anemia, vomiting,
GIT hyperirritability
Most notable gross lesion in cat are hugely enlarged
chocolate brown spleen, wider spread small pale focai on
liver, gastric & duodenal ulcer.
Diagnosis based on presence of mast cell in smear from
blood & bone marrow
Mast cell 20u in diameter & round, centrally or
eccentrically placed nucleus & cytoplasm packed with
small, uniform, purple granules
