Bone Labs Flashcards
Describe this lesion.
The basisphenoid/occipital articulation is irregular: the rostral fragment (basisphenoid) is displaced cranioventrally, relative to the caudal fragment (occipital bone). In addition, there are several small bone fragments free at the fracture site. There is hemorrhage dorsal and ventral to the fracture site at the insertion of the longus capitus muscle. The hemorrhage dorsally is exterior to the dura mater and compresses it
Give a morphological diagnosis for this lesion.
basisphenoid/occipital bones: fracture/dislocation with extradural hematoma
What is the cause of this lesion?
The lesion is commonly created when a horse falls backwards onto its poll. The extreme convulsive stretching of the capitus ventralis muscle can result in caudoventral displacement of the basisphenoid bone
What are the expected clinical signs with this lesion?
cerebral signs including ataxia and/or suffer from acute blindness secondary to optic nerve damage
Describe this lesion. History: Tissue from a 9-week old horse, patient was born with a large bump on its side but no other abnormalities.
Focally, the distal thoracic portion of the spinal column is deviated laterally to the right, rotating the spine clockwise. The spinal column is narrowed by 50% at the area of lateral deviation. The spinal cord is narrowed in that area.
Give a morphological diagnosis for this lesion.
Spinal Column: Congenital scoliosis with rotation
What are some possible causes of this lesion?
ingestion of several species of lupines, other alkaloid containing plants induce similar defects, and spontaneous genetic abnormalities
Describe this lesion. History: Tissue from a steer, calf received trauma to the right hind limb during transportation.
The distal tibial physis is thickened, fragmented and bordered by hemorrhage.
Give a morphological diagnosis for this lesion.
Right distal tibia: partial physeal fracture
What is the expected outcome or progression of this lesion?
Damage to the entire physis could result in no further longitudinal growth, whereas a focal physeal lesion leads to an angular limb deformity
A calf that sustained a similar trauma/ fracture presents a few months later with limb deformity. What term could be used to describe this deformity?
. A lateral deviation of the limb is called valgus deformity and can result from defects in the lateral aspect of the physis.
Describe this lesion. History: Tissue from a young macaque from a research colony. Many individuals within the colony have been experiencing fractures of long bones after very minimal trauma. Other individuals have had loosened or completely lost teeth. The macaques in this colony were fed a diet that predominately commercial monkey chow.
The maxilla is diffusely thickened and firm but pliable. The cut surface is homogenous and pale pink-tan, with no evidence of ossified tissue. The gum line and upper palate bulge, causing the teeth to protrude at approximately a 45 degree angle and a protrusion of the palate into the mouth, preventing jaw closure
Give a morphological diagnosis for this lesion.
Skull: diffuse fibrous osteodystrophy
What is the pathogenesis for this lesion?
Decreased vitamin D -> decreased Ca absorption by intestine -> decreased serum [Ca] -> increaseed parathyroid hormone (PTH) from parathyroid glands -> increased osteoclastic resorption from bone to increase serum Ca -> decreased bone density -> replacement by fibrous connective tissue
What is the most likely cause of the lesions in this group of macaques?
they were fed food deficient in vitamin D and calcium and high in phosphorus
If only a single individual was affected, what might be 2 other differentials?
Primary hyperparathyroidism as a result of a parathyroid gland adenoma can cause fibrous osteodystrophy. Functional parathyroid gland adenomas can produce large amounts of PTH. And renal failure which can cause secondary hyperparathyroidism
Describe this lesion. History: tissue from a dog.
There is bilateral enlargement of the mandibles. The enlarged area is firm and hard consistent with bone structure.
Give a morphological diagnosis for this lesion.
Mandible: bilateral, chronic, severe, diffuse mandibular hyperostosis
List possible differentials for this lesion.
craniomandibular osteopathy, fibrous osteodystrophy, mandibular osteoma/osteosarcoma, and chronic osteomyelitis
Describe this lesion. History: tissue from a finishing hog with chronic lameness.
The articular cartilage of head of the humerus contains a focal cavitation measuring 2 cm x 1 cm. The articular surface of the distal end of the humerus (lateral condyle) is multifocally roughened with multiple cavitations ranging in size from 0.5 to 1 cm in diameter which have lost the articular cartilage exposing reddened subchondral bone. There are also thickened foci of cartilage that have partially separated from underlying subchondral bone. The joint capsule is thickened and fibrotic.
Give a morphological diagnosis for this lesion.
humerus: multifocal osteochondrosis dissecans
What are some risk factors for this condition?
osteochondrosis tends to affect young, male, rapidy growing, large breeds of animals, especially dogs, cattle, horses, pigs, chickens, and turkeys
What is the pathogenesis for this lesion?
premature vessel closure causes focal AE ischemia leading to cartilage necrosis and focal endrochondrial ossifcation failure with adjacent endochondrial ossification progression leading to the deformity of the articular surface and finally necrotic cartilage breaks free from the joint
Describe this lesion. History: tissue from a 5-month old, female, great dane puppy. Several day history of forelimb lameness, fever and bilateral painful, swollen, distal antebrachia
On the anterior cortical surface of the radius and the posterior cortical surface of the ulna, there is a multifocal, irregular and variable proliferation of periosteal new bone extending from the metaphyses and along the diaphyses. The periosteum of both bones is mildly to moderately thickened by fibrous connective tissue. There is a cleft within the metaphysis that parallels the growth plate. There is a 2 mm wide band of white osseous tissue within the metaphysis that runs transversely between the cortices. Also, the distal end of the radius is deviated ventrally.
Microscopically, bone sections are characterized by necrosis of osteoblasts in the primary spongiosa at the metaphyses with infiltration by large numbers of neutrophils. Additionally, there is formation of periosteal new bone oriented perpendicular to the cortices intermixed with fibrous connective tissue. Give an appropriate morphologic diagnosis.
Radius and ulna: Chronic, severe, diffuse, necrosuppartive, metaphyseal osteomyelitis with cortical hyperostosiis and periosteal fibrosis
Name the condition.
metaphyseal ostepathy
If this dog was still alive what would be its prognosis?
the prognosis is generally good with complete resolution of clinical signs (diarrhea, poor fever, poor appetite, and weight loss)
Describe this lesion. History: tissue from a 5-year old, holstein dairy cow. The cow was sent to slaughter after failure to respond to treatment.
The mandible was expanded up to 10 cm in width by hard, tan to gray material (bone) and contained multifocal cavitations up to 3 cm in width filled with soft tan viscous material.
Histopathogy revealed large colonies of filamentous bacteria surrounded by neutrophils and macrophages. What is the most likely morphologic diagnosis?
mandible: chronic multifocal pyogranulomatous osteomyelitis
What is the common name for this condition?
lumpy jaw
What is the pathogenesis for this lesion?
The bacterium Actinomyces bovis, a commensal organism in the mouth, enters the gums and periodontal region through abrasions. Persistent, progressive infection and inflammation of the mandible result in areas of necrosis, extensive proliferation of new bone and formation of granulation tissue.
Describe this lesion. History: tissue from a 9-year old female labrador with a history of progressive hind limb paresis and presence of an anal sac mass
Anal sac: A 3cm X 3cm solid tan mass was located in the right anal sac. Vertebra: The vertebral body of L7 feels diffusely soft and is pliable. The body on cut surface was darker than adjacent vertebrae. The ventral aspect of vertebral body L7 had an irregular hard surface (periosteal proliferation). Sublumbar lymph nodes: The lymph nodes ventral to the lumbar vertebrae were diffusely enlarged with loss of corticomedullary distinction. Kidney: There were multiple 1/4 cm to 1/2 cm tan masses located along the corticomedullary junction and some equally sized masses visible on the cortical surface. Lung: There was a focal, firm, lobular, yellow nodule within the lung.
Histologically, the anal sac mass is composed of cords, lobules and palisading clusters of neoplastic cells occasionally forming pseudorosettes. Similar neoplastic cells were presented in the vertebrae. Give a morphological diagnosis for the vertebra.
vertebrae: metastatic anal sac adenocarcinoma
What abnormal blood chemical value might you find associated with this lesion?
hypercalcemia due to the production of parathyroid related peptide
Describe this lesion. History: the patient presented with swollen joints, anorexia, lethargy, and blindness
Expanding and effacing the basisphenoid bone and extending along the ventrolateral calvarium there was a soft, mottled tan to red 2X4 cm mass with irregular margins and a shaggy surface.
Give a morphological diagnosis for this lesion.
Calvarium: Chronic, locally extensive pyogranulomatous osteomyelitis with intralesional yeast bodies.
Identify A.
macrophages
Identify B.
neutrophils
Identify C.
coccidiodes
Describe this lesion. History: tissue from a 1.5 year old throughbred filly that had rear limb ataxia and a draining tract in the right lumbar area.
In the sacral vertebrae, the lateral portion of the vertebral body was widened, focally friable, and centrally contained an irregular cavity (2 x 1 x 1 cm) that was a pale yellow-green color. Effacing the affected transverse process the tissue was pale and thickened forming a semi-discrete mass-like structure.
Give a morphological diagnosis for this lesion.
vertebral body: focal, chronic, purulent osteomyelitis with sequestra and abcess
Describe this lesion. History: from a male castrated thoroughbred racehorse.
The tip of the right front P3 bone is ventrally rotated away from the dorsal hoof wall towards the sole. The lamellar space between the dorsal aspect of P3 and the dorsal hoof wall is expanded (approximately 0.5 dorsally and 1.5 cm ventrally) by a wedge of tannish, fibrous connective tissue and dysplastic hoof material.
Describe this lesion. History: from 19 year old Arabian horse.
The tip of the right hind P3 bone is ventrally rotated away from the dorsal hoof wall. The lamellar space between the dorsal aspect of P3 and the dorsal hoof wall is expanded (approximately 0.5 cm dorsally and 1.5 cm ventrally) by a wedge shaped, tannish, fibrous tissue and dysplastic hoof material. Focally, the tip of P3 has perforated through the cranial aspect of the sole. The tip of P3 is mildly eroded away (osteomyelitis) and there is a yellow- tannish fluid replacing it. There is a small tract or channel that connect the tip of P3 and the external environment (drainage tract
Give a morphological diagnosis for this lesion.
Hoof: chronic, diffuse, severe, laminitis with ventral rotation of P3
Give a morphological diagnosis for this lesion.
Hoof: chronic, diffuse, severe laminitis with ventral rotation and perforation of P3 and focally-extensive osteomyelitis
What are some potential causes or risk factors for laminits?
sepsis and endotoxemia, endocrinopathies, trauma and supporting limb laminitis, intake of lush pasture
Describe this lesion. History: tissue from an amputated left hindlimb of an 8-year old mixed breed dog. Radiographs revealed a lytic bone lesion with periosteal new bone growth.
The diameter of the proximal tibia was increased to 4 cm in diameter. On cut surface there was a locally extensive area of pale to reddish discoloration within the medullary cavity where normal marrow has been replaced by a firm, mineralized tissue. The cranial and caudal cortices are multifocally eroded or lost. There is prominent spiculated and columnar new bone growth originating from the periosteal surfaces.
Give a morphological diagnosis for this lesion.
Left proximal tibia: osteosarcoma
What is the prognosis for this lesion and what other organs might you check as a follow-up to this condition?
the prognosis is poor, thoracic radiographs to look for pulmonary metastases are recommended
Name possible differentials for canine bone mass.
osteosarcoma, chondrosarcoma, fibrosarcoma, histiocytic sarcoma, hemangiosarcoma, plasma cell myeloma, chronic osteomyelitis, fracture with bone callus
After determining what the mass is, what are some other primary sites where the same type of mass might be located in other patients?
proximal humerus and distal radius, and bones of the skull, jaw, and vertebral column
Describe this lesion. Tissue from a 1-month old foal. The foal presented with a five day history of hind limb ataxia. At the time of examination, the foal was unable and ambulate
There vertebral body of T5 had a light tan-brown colored lesion approximately 1 x 2 cm which extended cranially along the dorsal edge of the body of T4 and into the spinal canal. There were bilateral, fluid-filled cystic structures containing purulent exudate surrounding the ventral portion of T5 each measuring approximately 2 cm in diameter.
Give a morphological diagnosis for this lesion.
Vertebrae T4/5: Focal, chronic, severe, necrotizing osteomyelitis with ventral vertebral associated abscesses
How might this foal have gotten this lesion?
trauma or hematogenous spread
Describe this lesion. History: tissue from a 1.5 month old bull that presented with a 1-month history of polyarthropathy that was characterized by multiple swollen joints
The synovial surface was irregular, slightly reddened and roughened, the joint capsule was thickened. There is an accumulation of laminated fibrin on the synovial surface extending into the joint space. Also, there are multiple foci in which the articular cartilage is eroded and/or ulcerated
Give a morphological diagnosis for this lesion.
severe, chronic, diffuse, fibrinous osteoarthritis with multifocal ulcers of the articular cartilage and synovial fibrosis
Histologically there was marked fibrosis, neovascularization and an infiltrate of polymorphonuclear cells, lymphocytes and plasma cells along the articular cartilage adjacent to the ulcerated surface. What is the term for this reaction to injury and what are expected sequela?
The described change is called pannus. Growth of fibrovascular tissue over articular cartilage results in destruction of cartilage. The accumulation of fibrous tissue within the joint can progress to fibrous ankylosis whereby movement is restricted
Describe this lesion. History: tissue from a pig
Focally within the medullary cavity of the diaphysis there was a large yellow area on cut surface that was effaced by reddened trabecular bone. A similar focus was present at the distal metaphysis and the proximal epiphysis. The distal lesion extended through the articular cartilage
Give a morphological diagnosis for this lesion.
Tibia: chronic, severe, multifocal, purulent osteomyelitis tibiotarsal joint: severe, chronic, focal purulent osteoarthritis
Describe this lesion. History: horse presented with acute lameness after a race
Right radial carpal bone: The radial carpal bone was separated into 4 pieces with sharp, irregular margins and multiple smaller fragments. All bone fragments were contained within the intermediocarpal joint. The articular cartilage of adjacent carpal bones (C2 and C3) was multifocally ulcerated. The periarticular soft tissue is discolored red (hemorrhage) and expanded by a clear gelatinous fluid (edema).
Give a morphological diagnosis for this lesion.
Right radial carpal bone: Acute, severe, comminuted fracture of the right radial carpal bone Cranioproximal C2 and C3: Acute multifocal ulceration of articular cartilage.
Describe this lesion. History: tissue from a 9-year old quarterhorse gelding. The patient presented with a laceration on the plantar surface of the distal left hind foot.
There is a red raised area of granulation tissue 3 cm in diameter present on the plantar surface just proximal to the coronary band associated with a deep laceration. This granulation tissue communicates internally with and surrounds the superficial digital flexor, deep digital flexor, and suspensory ligament. The navicular bone is displaced proximally and P2 is subluxated caudally. The distal interphalangeal joint and the navicular bursa contain red, proliferative tissue.
Give a morphological diagnosis for this lesion.
left hind foot: chronic tenosynovitis of the superficial digital flexor, deep digital flexor, and suspensory ligament and Chronic, proliferative arthritis and bursitis of the distal interphalangeal joint and navicular bursa
Describe this lesion. History: tissue from a 5 year old, thoroughbred mare. Patient presented with a long-term history of intermediate lameness
There are multifocal depressions on the cannon bone articular surface approximately 0.5-1 cm in diameter that extended deep into the subchondral bone. An incomplete linear fracture line was present at the articular surface of the medial condyle.
Give a morphological diagnosis for this lesion.
Cannon bone, articular surface: mild, chronic, multifocal osteochondrosis with an acute incomplete condylar fracture
What is the pathogenesis for this lesion?
premature closure of cartilage canal blood vessel at the AW complex or the physis leading to focal ischemic necrosis of growth cartilage leading to failure of endochondral ossification
Describe this lesion. History: tissue from an 8-year old mixed breed dog. The patient had a chronic history of lameness and trouble rising in the hind end.
Coxofemoral Joint: Focally, there is an oval area of the femoral head that exhibits loss of articular cartilage with a shiny, thickening of the underlying subchondral bone (eburnation). On the joint capsule margins of both the femur and acetabulum of the pelvis, there are numerous, coalescing, small, irregular to round boney projections arising from the joint capsule margins (osteophytes). Within the joint capsule, the synovial membrane is thickened by villous- like projection (synovial hyperplasia).
Give a morphological diagnosis for this lesion.
Coxofemoral joint: chronic, severe, locally extensive, osteoarthritis with osteophytes, articular erosions, ulcerations, eburnation of bone, and synovial proliferation
Define eburnation.
Eburnation is the sclerosis or thickening underlying subchondral bone. Eburnation occurs as the result of decreased articular cartilage and exposure of underlying subchondral bone with subsequent compression.
