|
|
| (4 intermediate revisions by the same user not shown) |
| Line 7: |
Line 7: |
| | ***Grossly: | | ***Grossly: |
| | ****Thickened and edematous periskeletal soft tissue and periosteum of the lower legs | | ****Thickened and edematous periskeletal soft tissue and periosteum of the lower legs |
| − | ****Multifocal [[Parasitic Myositis|parasitic myositis]] | + | ****Multifocal [[Muscles Inflammatory - Pathology#Parasitic myositis|parasitic myositis]] |
| | ***Histologically: | | ***Histologically: |
| | ****Swelling and hypertrophy of osteoprogenitor cells | | ****Swelling and hypertrophy of osteoprogenitor cells |
| | ****Hyperplasia of spindle cells | | ****Hyperplasia of spindle cells |
| | ****Osteoid is produced | | ****Osteoid is produced |
| − | | + | *[[More Hepatozoon|More detail on ''Hepatozoon americanum'']] |
| | *Myositis | | *Myositis |
| | **Develop cysts in skeletal muscle of dogs and cats | | **Develop cysts in skeletal muscle of dogs and cats |
| | **May be accompanied by pyogranulomatous myositis - macrophages and [[Neutrophils|neutrophils]] mainly with occasional other cells | | **May be accompanied by pyogranulomatous myositis - macrophages and [[Neutrophils|neutrophils]] mainly with occasional other cells |
| − |
| |
| − |
| |
| − | '''[Skeletal lesions of canine hepatozoonosis caused by Hepatozoon americanum. Panciera Rj et al. Vet Path (2000) 37 225-230]'''
| |
| − |
| |
| − | *[[Coccidia|'''''Hepatozoon americanum''''']]
| |
| − | **SE USA
| |
| − | **Clinical signs:
| |
| − | ***Fever
| |
| − | ***Weakness
| |
| − | ***Myalgia
| |
| − | ***Bone pain
| |
| − | ***Mature neutrophilic leukocytosis
| |
| − | ***Wasting
| |
| − | ***Poor response to treatment
| |
| − | ***Periosteal new bone formation
| |
| − | **Much more aggressive and higher mortality rate than the disease in the Old World
| |
| − | **Gross skeletal lesions:
| |
| − | ***Markedly thickened and edematous periskeletal soft tissue and periosteum of the lower legs ***+/- petechiation
| |
| − | ***Eccentrically or circumferentially arranged plaques of new bone formation deposited on the original cortex
| |
| − | ***Boney plaques look ‘porous’ to compact, often in layers with the spongey areas covered by more compact bone
| |
| − | ***No evidence of endosteal bone formation
| |
| − | ***Periosteoproliferative lesions most prominent in proximal long bones of the limbs (esp. femur and humerus)
| |
| − | ***Metaphyses usually spared
| |
| − | ***Caudal and lateral surfaces of the proximal tibia and fibular and radius and ulnar diaphyses affected
| |
| − | ***Distal diaphyses and metaphyses less severely affected/free from lesions
| |
| − | ***Metacarpals/tarsals mildly affected
| |
| − | ***Lateral surface of scapula affected
| |
| − | ***Axial skeleton less severely affected
| |
| − | ***Often bones of the skull prominently affected – orbits, rostrolateral maxilla and mandible, lateral aspect of zygomatic arch
| |
| − | ***Lateral aspects of vertebral arches and spinous processes sometimes affected
| |
| − | ***Ribs normal
| |
| − | ***Multifocal [[Parasitic Myositis|parasitic myositis]]
| |
| − | **Histologically:
| |
| − | ***Earliest change in periosteum -> swelling and hypertrophy of osteoprogenitor cells in the deeper layers of the periosteum
| |
| − | ***Spindle cells become stellate and plumper
| |
| − | ****Become aligned in single or multiple layers
| |
| − | ****Undergo hyperplasia creating a thick and densely cellular zone on the cortical surface
| |
| − | ***Osteoid is produced and osteoblasts become entrapped forming spiccules of trabecular new bone
| |
| − | ***New spicules arranged perpendicular to the cortical surface
| |
| − | ***With time, considerable osteoclastic activity, remodeling occurs firstly adjacent to the older cortex and then extends outwards
| |
| − | ***As the remodeling continues, the spicules become longitudinally arranged
| |
| − | ***Pseudocortices form that can contain bone marrow parenchyma
| |
| − | ***Endothelial hypertrophy prominent in vessels adjacent and within the periosteum
| |
| − | ***Severe edema present in adjacent soft tissue
| |
| − | ***Muscle atrophy and fibrosis often accompanied the edema
| |
| − | ***No evidence of inflammation
| |
| − | ***No parasites in adjacent muscle/soft tissue
| |
| − | **Lesions develop in young dogs, within 5wks of experimental infection and progress rapidly, looking just like hypertrophic osteopathy
| |
| − | **No obvious link between site of infection and generalized boney lesions
| |
| − | *Differentials for periosteal new bone formation:
| |
| − | **[[Hypertrophic Osteopathy|Hypertrophic osteopathy]]
| |
| − | **[[Craniomandibular Osteopathy|Craniomandibular osteopathy]]
| |
| − | **[[Panosteitis|Canine panosteitis]]
| |
| − | **[[Hypertrophic Osteodystrophy|Hypertrophic osteodystrophy]]
| |
| − | *Hypertrophic osteoarthropathy
| |
| − | **V difficult to distinguish from this syndrome
| |
| − | **Again no inflammation, histologically look identical, but these cases don’t have an abdominal/thoracic mass, and HO usually starts on the metacarpals/tarsals
| |
| − | *?Pathogenesis
| |
| − | **Thought to occur secondary to increased blood flow and fluid retention within the limbs, leading to vascular and then periosteal proliferation
| |
| − |
| |
| − |
| |
| | [[Category:Miscellaneous Protozoa]][[Category:To_Do_-_Parasites]] | | [[Category:Miscellaneous Protozoa]][[Category:To_Do_-_Parasites]] |
| − | [[Category:Bones - Pathology]]
| |