Known as “brittle bone disease”.
Osteogenesis Imperfecta (TOPNOTCH)Robbins Basic Pathology,8th ed., p802
This is a group of hereditary disorders caused by defective synthesis of type I collagen. Classic finding of a “blue sclerae” is seen in one type of this disorder.
Osteogenesis Imperfecta (TOPNOTCH)Robbins Basic Pathology,8th ed., p802
Characterized by , disproportionate shortening of the proximal extremities, bowing of the legs, and a lordotic (sway-backed) posture.
Achrondroplasia (TOPNOTCH)Robbins Basic Pathology,8th ed., p802
A group of rare genetic disorders characterized by reduced osteoclast-mediated bone resorption and therefore defective bone remodelling. Literally means “stone bone”.
Osteopetrosis(TOPNOTCH)Robbins Basic Pathology,8th ed., p802
The hallmark of this disease is loss of bone which tends to be most conspicuous in trabecular bone. The bony trabeculae are thinner and more widely separated than usual, resulting in an increased susceptibility to fractures.
Osteoporosis (TOPNOTCH)Robbins Basic Pathology,8th ed., p804
Characterized by repetitive episodes of frenzied, regional osteoclastic activity and bone resorption, followed by exuberant bone formation, and finally by an apparent exhaustion of cellular activity. Pathognomonic feature is a “mosaic pattern” of lamellar bone.
Paget Disease (Osteitis Deformans) (TOPNOTCH)Robbins Basic Pathology,8th ed., p806
The hallmark of this disease is increased osteoclastic activity, with bone resorption. This leads to characteristic radiographic changes best seen along the radial aspect of the middle phalanges of the second and third fingers.
Hyperparathyroidism (TOPNOTCH)Robbins Basic Pathology,8th ed., p808
Characterized by dead bone with empty lacunae is interspersed with areas of fat necrosis and insoluble calcium soaps. The cortex is usually not affected because of collateral blood supply.
Osteonecrosis (avascular necrosis)(TOPNOTCH)Robbins Basic Pathology,8th ed., p809
Inflammation of the bone and marrow cavity.
Osteomyelitis(TOPNOTCH)Robbins Basic Pathology,8th ed., p809
What do you call the dead entrapped bone seen in infected sites of bones affected with osteomyelitis?
Sequestrum(TOPNOTCH)Robbins Basic Pathology,8th ed., p809
What do you call the shell of living tissue around a segment of devitalized bone?
Involucrum (TOPNOTCH)Robbins Basic Pathology,8th ed., p809
Benign bone tumor characterized as exophytic growths attached to bone surface of the face and skull, which may histologically resemble normal bone.
Osteoma(TOPNOTCH)Robbins Basic Pathology,8th ed., p811
Benign bone tumor that are cortical tumors, histologically described as interlacing trabeculae of woven bone. Characteristic symptom is pain. Common locations include the metaphyses of the femur and tibia.
Osteoid osteoma(TOPNOTCH)Robbins Basic Pathology,8th ed., p811
These bone-forming lesions arise in vertebral transverse and spinous processes of the vertebral column, which may be histologically similar to osteoid osteoma.
Osteoblastoma(TOPNOTCH)Robbins Basic Pathology,8th ed., p811
A bone-producing malignant mesenchymal tumor, characterized as gritty, gray-white tumors, often exhibiting hemorrhage and cystic degeneration. The production of mineralized or unmineralized bone (osteoid) by malignant cells is essential for diagnosis.
Osteosarcomas(TOPNOTCH)Robbins Basic Pathology,8th ed., p811
These are relatively common benign hyaline cartilage-capped outgrowths attached by a bony stalk to the underlying skeleton.
Osteochondromas (TOPNOTCH)Robbins Basic Pathology,8th ed., p814
These are benign tumors of hyaline cartilage, described as gray-blue, translucent well-circumscribed nodules. May be seen in metaphyseal regions of tubular bones of the hands and feet. On x-ray, the unmineralized nodules of cartilage produce well-circumscribed oval lucencies surrounded by thin rims of radiodense bone (O-ring sign).
Enchondromas (TOPNOTCH)Robbins Basic Pathology,8th ed., p814
Chondromas seen on the bone surface.
Juxtacortical chondromas(TOPNOTCH)Robbins Basic Pathology,8th ed., p814
These lesions arise within the medullary cavity of the bone to form an expansile glistening mass that often erodes the cortex. They exhibit malignant hyaline and myxoid cartilage.
Conventional chondrosarcomas (TOPNOTCH)Robbins Basic Pathology,8th ed., p814
These tumors are characterized as viscous and gelatinous, with the matrix oozing from the cut surface. Spotty calcifications are typically present, with central necrosis creating cystic spaces.
Myxoid chondrosarcomas(TOPNOTCH)Robbins Basic Pathology,8th ed., p815
Presents as sharply demarcated radiolucencies surrounded by a thin zone of sclerosis. They are gray to yellow-brown, and microscopically are cellular lesions composed of cytologically benign fibroblasts and macrophages. The fibroblasts classically exhibit a “storiform (pinwheel) pattern”.
Fibrous Cortical Defect and Nonossifying Fibroma (TOPNOTCH)Robbins Basic Pathology,8th ed., p815
A benign tumor of the bone wherein all components of normal bone are present, but they fail to differentiate into mature structures. Curved trabeculae of woven bone mimick “Chinese characters” histologically.
Fibrous Dysplasia (TOPNOTCH)Robbins Basic Pathology,8th ed., p816
Primary malignant small round-cell tumor of bone and soft tissue, characterized by Sheets of small round cells with scant, cleared cytoplasm, circled about a central fibrillary space or “Homer-Wright rosettes”.
Ewing sarcoma (TOPNOTCH)Robbins Basic Pathology,8th ed., p817
A relatively uncommon benign tumor usually arising in individuals in their 20s to 40s. These are large and red-brown lesions with frequent cystic degeneration, composed of uniform oval mononuclear cells with frequent mitoses, with scattered osteoclast-type giant cells containing 100 or more nuclei.
Giant-cell tumors (GCTs)(TOPNOTCH)Robbins Basic Pathology,8th ed., p817
These are the most common malignant tumor of bone.
Metastatic tumors (TOPNOTCH)Robbins Basic Pathology,8th ed., p818
Pathways of metastasis to the bone.
1) direct extension, (2) lymphatic or hematogenous dissemination, (3) intraspinal seeding(TOPNOTCH)Robbins Basic Pathology,8th ed., p818
Characterized by fibrillation and cracking of the articular cartilage matrix, bone eburnation, and bony outgrowths/spurs (osteophytes). Full-thickness portions of the cartilage are lost, and the subchondral bone plate is exposed.
Osteoarthritis (TOPNOTCH)Robbins Basic Pathology,8th ed., p819
Characterized by a dense neutrophilic infiltrate permeating the synovium and synovial fluid. Long, slender, needle-shaped monosodium urate crystals are frequently found in the cytoplasm of the neutrophils as well as in small clusters in the synovium.
Acute gouty arthritis(TOPNOTCH)Robbins Basic Pathology,8th ed., p821
Results from repetitive precipitation of urate crystals during acute attacks. The synovium becomes hyperplastic, fibrotic, and thickened by inflammatory cells, forming a pannus that destroys the underlying cartilage.
Chronic tophaceous arthritis (TOPNOTCH)Robbins Basic Pathology,8th ed., p821
Formed by large aggregations of urate crystals surrounded by an intense inflammatory reaction of lymphocytes, macrophages, and foreign-body giant cells, attempting to engulf the masses of crystals. Pathognomonic feature of gout.
Tophi (TOPNOTCH)Robbins Basic Pathology,8th ed., p821
Refers to multiple different renal complications associated with urate deposition, variously forming medullary tophi, intratubular precipitations, or free uric acid crystals and renal calculi.
Gouty nephropathy(TOPNOTCH)Robbins Basic Pathology,8th ed., p821
Also known as chondrocalcinosis or-more formally-calcium pyrophosphate crystal deposition disease. The crystals are weakly birefringent, rhomboid in shape with blunted ends.
Pseudogout (TOPNOTCH)Robbins Basic Pathology,8th ed., p823
Main causative agent of suppurative arthritis in children under 2 years old.
Haemophilus influenzae(TOPNOTCH)Robbins Basic Pathology,8th ed., p824
Main causative agent of suppurative arthritis in older children and adults.
Staphylococcus aureus(TOPNOTCH)Robbins Basic Pathology,8th ed., p824
Main causative agent of suppurative arthritis in late adolescence and young adulthood.
Neisseria gonorrhea(TOPNOTCH)Robbins Basic Pathology,8th ed., p824
Individuals with sickle cell disease are prone to developing osteomyelitis and suppurative arthritis caused by this agent.
Salmonella(TOPNOTCH)Robbins Basic Pathology,8th ed., p824
Arthritis caused by infection with the spirochete Borrelia burgdorferi, transmitted by deer ticks of the Ixodes ricinus complex.
Lyme arthritis (TOPNOTCH)Robbins Basic Pathology,8th ed., p824
A small (<1.5 cm) cyst located near a joint capsule or tendon sheath, most commonly the wrist, which manifest as a firm to fluctuant pea-sized nodule.
Ganglion cyst(TOPNOTCH)Robbins Basic Pathology,8th ed., p825
The most severe and the most common form of muscular dystrophy. Characterized by marked variation in muscle fiber size, caused by concomitant myofiber hypertrophy and atrophy. The definitive diagnosis is based on the demonstration of abnormal staining for “dystrophin” in immunohistochemical preparations.
Duchenne muscular dystrophy (DMD) (TOPNOTCH)Robbins Basic Pathology,8th ed., p825
This can present as either acute or chronic proximal muscle weakness, and can precede the onset of other signs of thyroid dysfunction. Findings include myofiber necrosis, regeneration, and interstitial lymphocytes.
Thyrotoxic myopathy (TOPNOTCH)Robbins Basic Pathology,8th ed., p830
This can occur with binge drinking, where there is an acute toxic rhabdomyolysis with accompanying myoglobinuria that can cause renal failure. On histology, there is myocyte swelling and necrosis, myophagocytosis, and regeneration.
Ethanol myopathy (TOPNOTCH)Robbins Basic Pathology,8th ed., p830
An autoimmune disorder of the neuromuscular junction characterized by muscle weakness which first manifests in the extraocular muscles. Caused by circulating antibodies to the skeletal muscle acetylcholine receptors (AChRs).
Myasthenia gravis (TOPNOTCH)Robbins Basic Pathology,8th ed., p830
This syndrome characteristically develops as a paraneoplastic process most commonly in the setting of small-cell lung carcinoma. Presents with muscle weakness secondary to decreased vesicle release in response to presynaptic action potential.
Lambert-Eaton Myasthenic Syndrome (TOPNOTCH)Robbins Basic Pathology,8th ed., p830
Soft tissue tumor which presents as soft, gelatinous, grapelike masses on the surfaces of the bladder or vagina.
Sarcoma botryoides(TOPNOTCH)Robbins Basic Pathology,8th ed., p830
It is the most common soft tissue sarcoma of childhood and adolescence, usually appearing before age 20.
Rhabdomyosarcoma (TOPNOTCH)Robbins Basic Pathology,8th ed., p831
Diagnostic cell in rhabdomyosarcoma, characterized as round or elongated cells that may contain cross-striations visible by light microscopy.
Tadpole or strap cells(TOPNOTCH)Robbins Basic Pathology,8th ed., p831
Soft, yellow, well-encapsulated masses of mature adipocytes; they can vary considerably in size. Histologically, they consist of mature white fat cells with no pleomorphism
Lipoma (TOPNOTCH)Robbins Basic Pathology,8th ed., p832
Malignant neoplasms of adipocytes, which usually present as relatively well-circumscribed lesions. Diagnostic feature are lipoblasta, similar to fetal fat cells, with cytoplasmic lipid vacuoles that scallop the nucleus.
Liposarcomas (TOPNOTCH)Robbins Basic Pathology,8th ed., p833
A self-limited, reactive fibroblastic proliferation that typically occurs in adults on the volar aspect of the forearm. Consists of plump, randomly arranged, immature-appearing fibroblasts in an abundant myxoid stroma. Not a true tumor.
Nodular Fasciitis(TOPNOTCH)Robbins Basic Pathology,8th ed., p833
This develops in the proximal muscles of the extremities in athletic adolescents and young adults after trauma. Distinguished from other fibroblastic proliferations by the presence of metaplastic bone. Excision is curative.
Myositis Ossificans (TOPNOTCH)Robbins Basic Pathology,8th ed., p833
Malignant neoplasms composed of fibroblasts. These are soft unencapsulated, infiltrative masses frequently with areas of hemorrhage and necrosis. Malignant spindle cells are arranged in a “herringbone pattern”.
Fibrosarcoma (TOPNOTCH)Robbins Basic Pathology,8th ed., p834
These are relatively common benign lesions in adults presenting as circumscribed, small (
Benign Fibrous Histiocytoma (Dermatofibroma) (TOPNOTCH)Robbins Basic Pathology,8th ed., p834
A variety of soft tissue sarcomas Characterized by considerable cytologic pleomorphism, the presence of bizarre multinucleate cells, and “storiform” architecture .
Malignant fibrous histiocytoma (MFH) (TOPNOTCH)Robbins Basic Pathology,8th ed., p834
Benign smooth muscle tumors described as well-circumscribed neoplasms that can arise from smooth muscle cells anywhere in the body, but are encountered most commonly in the uterus.
Leiomyoma (TOPNOTCH)Robbins Basic Pathology,8th ed., p835
These commonly present as firm, painless masses of the skin, deep soft tissues of the extermities and retroperitoneum. Histologically, they show spindle cells with cigar-shaped nuclei arranged in interweaving fascicles.
Leiomyosarcoma (TOPNOTCH)Robbins Basic Pathology,8th ed., p835
What is the mineral that gives bone strength and hardness and is the storehouse for 99% of the body’s calcium, 85% of the body’s phosphorous, and 65% of the body’s sodium and magnesium?
Calcium Hydroxyapatite (TOPNOTCH)
Of all the proteins in the bone matrix, which one is unique to the bone?
Identify the bone cell: responsible for bone resorption
Identify the bone cell: most numerous than any other bone forming cell
Identify the bone cell: initiate the process of mineralization and express cell surface receptors that bind many hormones
What is the functional unit of bone?
Osteoblast and Osteoclast act in coordination and are considered the functional unit of bone known as the Basic Multicellular Unit (TOPNOTCH)
In what part of the bone can you see the histological abnormalities seen in achondroplasia?
Growth plate (TOPNOTCH)
Gross appearance: lack a medullary canal and the end of long bones are bulbous (Erlenmeyer Flask Deformity) and misshapen. The neural foramina are small and compress exiting nerves
What is the main defect in Osteopetrosis?
Deficient Osteoblastic Activity (TOPNOTCH)
Osteoporosis cannot be reliably detected in plain radiographs until how much of the bone mass is lost?
What is the histologic hallmark of Paget Disease of the bone?
Mosaic pattern of lamellar bone (Jigsaw pattern) (TOPNOTCH)
A variety of tumor and tumor like conditions develop in pagetic bone. However, what is the most dreaded complication of this condition?
Sarcoma (Osteosarcoma > Malignant Fibrous Histiocytoma, or chondrosarcoma) (TOPNOTCH)
80% of cases, what bone is involved in Paget DIsease?
Axial skeleton and proximal femur (TOPNOTCH)
What is the most common site of tuberculous osteomyelitis?
Spine (thoracic and lumbar) > knees and hips (TOPNOTCH)
Most cases of osteomyelitis reach the bone via what route?
What do you call a small intraosseous abscess that frequently involves the cortex and is walled off by reactive bone?
Brodie abscess (TOPNOTCH)
What do you call the morphologic variant of osteomyelitis that typically develops in the jaw and is associated with extensive new bone formation that obscures much of the underlying osseous structures?
Sclerosing osteomyelitis of Garre (TOPNOTCH)
What do you call a dead piece of bone?
Reactive woven or lamellar bone may be deposited and when it forms a sleeve of living tissue around a segment of devitalized bone, it is known as?
Morphology: Edematous granulation tissue containing numerous plasma cells and necrotic bone
Congenital Syphilitic Bone infection and Acquired syphillis (TOPNOTCH)
What is the most common primary malignant tumor of bone, exclusive of myeloma and lymphoma, and accounts for approximately 20% of primary bone cancers.
What are the 3 conditions associated with the development of osteosarcoma?
- Paget disease2. Bone infarcts3. Prior irradiation (TOPNOTCH)
What part of the bone do osteosarcomas usually arise?
Metaphyseal region of the long bone of the extremities, 60% occur about the knee. (TOPNOTCH)
Morphology: Coarse, lacelike pattern of neoplastic bone produced by anaplastic malignant tumor cells
Morphology: sheets of uniform small, round cells that are slightly larger than lymphocytes with small amounts of clear cytoplasm.
Ewing Sarcoma (TOPNOTCH)
Morphology: Presence of Homer Write rosettes ( tumor cells are arranged in a circle about a central fibrillary space)
Ewing Sarcoma (TOPNOTCH)
The diagnostic cell of embryonal, alveolar, and pleomorphic variants of Rhabdomyosarcoma which contains eccentric eosinophilic granular cytoplasm rich in thick and thin filaments
Tadpole or strap cells are seen in what soft tissue tumor?
Morphology: characterized by malignant spindle cells that have cigar shaped nuclei arranged in interweaving fascicles.
Morphology: histological hallmark is the dual line of differentiation of tumor cells, epithelial like cells and spindle cells
Synovial Sarcoma (TOPNOTCH)
Gross morphology: unencapsulated, infiltrative, soft, fish flesh masses, often having areas of hemorrhage and necrosis
These cells mimic fetal fat cells and contain round clear cytoplasmic vacuoles of lipid that scallop the nucleus. Seen in liposarcoma.
Morphology: consist of mature white fat cells with no pleomorphism
Pathognomonic hallmark of gout
What are the most common cutaneous lesions seen in RA?
Rheumatoid Nodules (TOPNOTCH)
The most important factors in the development of Osteoarthritis
Aging and mechanical effects (TOPNOTCH)
Bone eburnation and joint mice are seen in what disease entity?
The most common cancers that metastasize to the bone are?
Prostate, breast, kidney, and lung (TOPNOTCH)
What bones are most commonly involved in skeletal metastasis?
In descending order: Axial skeleton ( vertebral column, pelvis, ribs, skull, and sternum), proximal femur, and humerus (TOPNOTCH)
Skeletal metastases are typically multifocal, however, what carcinomas that metastasize to the bone are notorious for producing solitary lesions?
Ca of Kidney and Thyroid (TOPNOTCH)
morphology: uniform oval mononuclear cells that have indistinct cell membranes and appear to grow in syncitium with scattered numerous osteoclast type giants cells having 100 or more nuclei that have identical features to those of the mononuclear cells
Giant cell Tumor (TOPNOTCH)
Morphology: trabeculae mimic chinese characters
Fibrous Dysplasia (TOPNOTCH)
Morphology: Storiform pattern or pinwheel pattern created by benign spindle cells with scattered osteoclast
Fibrous cortical defect and nonossifying fibroma (TOPNOTCH)
What is the primary characteristic of osteosarcoma?
The formation of bone by the tumor cells (TOPNOTCH)
The combined picture of increased bone cell activity, peritrabecular fibrosis, and cystic brown tumors is the hallmark of what disease of abnormal mineral homeostasis?
Hyperparathyroidism (Generalized osteitis fibrosa cystica or von Recklinghausen disease of the bone) (TOPNOTCH)
What is the xray pattern that is virtually diagnostic of hyperparathyroidism?
Subperiosteal resorption producing thinned cortices in the middle phalanges of the index and middle finger and loss of the lamina dura around the teeth (TOPNOTCH)
What is the most important prognostic feature of a bone sarcoma?
Histological grade (TOPNOTCH)
O ring sign is seen in what cartilage forming tumor?
Morphology: chicken wire pattern of mineralizaton
Myositis ossificans is distinguised from the other fibroblastic proliferations by the presence of what structure?
Metaplastic bone (TOPNOTCH)