JOINT MUSCLE SOFT TISSUE

sway-backed posture. The cartilaginous growth plates contain hypoplastic or disorganized aggregates of chondrocytes instead of the long, orderly columns normally seen at this site. Osteogenesis Imperfecta OI or brittle bone disease, is a group of hereditary conditions characterized by abnormal development of type I collagen. Type I collagen is present in many different tissues, including skin, joints and eyes. OI characterized by the present of multiple bone fractures. Other tissues containing type I collagen are also affected, resulting in abnormal dentition, hearing loss, and blue appearance to the sclera. Osteoporosis is a skeletal disorder characterized by low bone mass and microarchitectural deterioration with a subsequent increase in bone fragility and susceptibility to fracture. It occurs most commonly as primary disorders or secondary. Osteoporosis result when imbalance occurs between bone formation and resorption. The hallmark of osteoporosis is a loss of bone, the bony trabeculae are thinning and widening of haversian canal. Both rickets and osteomalacia are manifestations of vitamin D deficiency. The fundamental change in these diseases is defective mineralization of bone, accompanied by an increase in nonmineralized osteoid. In rickets, the defective mineralization involves the developing bones in children, but osteomalacia involves the bone that has completed its normal development. Osteomyelitis designated as inflammation of the bone and marrow cavity by infectious agents. Osteomyelitis may be an acute or chronic. The most common etiologic agents are pyogenic bacteria and mycobacterium tuberculosis. Morphologically acute pyogenic osteomyelitis characterized by an intense, neutrophilic inflammatory infiltrate. Chronic osteomyelitis show sequestrum, involucrum and Brodie abscess. Tuberculous osteomyelitis causes the granulomatous inflammatory reaction. Bone tumors divided in two categories : bone-forming tumors osteoma, osteoid osteoma and osteoblastoma, and osteosarcoma and cartilaginous tumors osteochondroma, chondroma, and chondrosarcoma. - Osteosarcoma is malignant mesenchymal neoplasm in which the neoplastic cells produce osteoid. Most unknown etiology. The lesion usually in the mataphyseal region of the bone, often elevates the periosteum toproduce the Codman triangle on radiographs. The hallmark of osteosarcoma is the formation of osteoid by malignant mesenchymal cells, that may be spindle shaped, pleomorphic, bizarre, and giant cell often present. - Osteochondroma is benign proliferations composed of mature bone and a cartilaginous cap. Probably represent malformations rather than true neoplasm. - Chondrosarcoma is malignant neoplasm populated by mesenchymal cells that produce a cartilaginous matrix. Microscopically, chondrosarcoma vary great in appearance. There are well, moderately or poorly differentiated malignant cells, multinucleate cells are present with lacunae containing 2 or more chondrocytes. - Ewing sarcoma occurs predominantly in children and adolescents, with a peak incidence in the second decade of life. Ewing sarcoma arises within the medullary cavity of the affected bone to produce a soft, expansile mass. Microscopically it composed of sheets of primitive cells, with small, fairly uniform nuclei and only scant cytoplasm. - Fibrous dysplasia is an uncommon, benign, tumor-like lesion of bone, in which the normal trabecular bone is replaced by proliferating fibrous tissue and disorderly islands of malformed bone.

2. JOINT

Osteoarthritis also termed degenerative joint disease. In most cases it arises without obvious predisposing factors primary. Morphologically, the earliest structural changes are enlargement disorganization of the chondrocytes in the superficial part of the articular cartilage. These accompanied by fibrillation splitting at the articular surface. Portions of the articular cartilage are eventually completely eroded, cyst may form in the underlying bone. Udayana University Faculty of Medicine, DME 26 Additional bone proliferation occurs at the margins of the joints to produce bony excrescences, termed osteophytes. Non specific inflammation can develops. Gout is a disorder caused by the tissue accumulation of excessive amounts of uric acid, an end product of purine metabolism. The major morphologic manifestation of gout are acute arthritis, chronic tophaceous arthritis and soft tissue tophi, and gouty nephropathy. The most common form of infectious arthritis is caused by bacteria. The usual reaction manifested by local pain, fever and an intense neutrophilic inflammatory infiltrate within the joint and periarticular tissues.

3. MUSCLE

Rhabdomyosarcoma is predominantly a neoplasm of infancy, childhood and adolescence, with the peak incidence in the first decade of life. Microscopically there are three variants : embryonal, alveolar and pleomorphic. Leiomyoma is common benign smooth muscle tumors, encountered most frequently in the uterus, composed of hyperplasia of smooth muscle cells arrayed in whorled-like without anaplastic appearance. Leiomyosarcoma is malignant smooth muscle tumors, occur most often in the uterus and gastrointestinal tracts, composed of hyperplasia of smooth muscle cells with anaplastic appearance, with infiltrative growth.

4. SOFT TISSUE

Soft tissue tumors are generally classified on the basis of tissue type that they recapitulate, including tumors of adipose tissue lipoma and liposarcoma, tumors of fibrous tissue fibroma and fibrosarcoma. Lipoma is benign tumor, soft, yellow mass, composed of mature adipose tissue. Liposarcoma is malignant neoplasm, a number of different histologic subtypes are recognized, including well-differentiated, myxoid, round cell, pleomorphic and dedifferentiated liposarcoma. Fibrosarcoma is malignant neoplasm, composed of interlacing fascicles of fibroblast, sometimes arranged in a ‘herringbone’ pattern. SCENARIO A 72 years old woman came to a general hospital with chief complain pain and swelling in proximal region of her right lower extremity, after she fall in the bathroom. Radiograph examination showed fracture of femoral neck and decreased of bone density. Learning task : 1.1 What is the possible diagnosis of this patient ? 1.2 What are the role of hormonal factors in this case ? 1.3 Describe the morphologic features of the femoral bone of this patient. A 22 years old man came to a doctor with chief complain swelling and pain in his knee, enlarge fast since a week ago. Radiograph examination showed lesion in metaphyseal region of distal femur, destroy the cortex, elevate periosteum and extend into the soft tissue. Biopsy was done in this patient. Learning task : 2.1.What is the possible diagnosis of this patient ? 2.2 Describe the morphologic features of the biopsy specimen. A 35 years old man came to a general hospital with chief complain subcutaneous masses, enlarge slowly since about 3 years ago, without pain. Biopsy was done in this patient. The result of histopathological examination was lipoma. Learning task :

3.1 Describe the morphologic features macroscopic and microscopic of the biopsy

specimen from this patient. Udayana University Faculty of Medicine, DME 27 3.2 Mention some histopatological variant of lipoma. Self Assessment

1. BONE