Clinical signs:
Osteochondroma is usually a solitary bony projection covered with cartilaginous cap. Bony base arises on the external surface of bone, its marrow cavity is continuous with that of underlying bone. Osteochondroma is a common bone tumour affecting mostly distal femur, upper humerus, upper tibia and fibula. Smaller proportion of patients develop multiple lesions (osteochondromatosis, multiple hereditary exostoses). Osteochondroma may not represent true neoplasm. It is rather malformation resulting from displaced epiphyseal cartilage that herniates through a periosteal defect, and then continues to grow at 90 degrees to the normal growth plane. Completely covered with periosteum, osteochondroma growths synchronously with the epiphyseal plate during the first two decades of life.
Macroscopic appearance:
Osteochondroma may be flat, sessile or mushroom-shaped projection, long and slender. Outer surface has smooth surface or knobby cartilaginous areas. On cut section, the central bony stalk is covered by cartilaginous cap, usually 5.0 – 10.0 mm in thickness. Cartilaginous cap thicker than 20 mm raises suspition of malignant transformation.
Histology:
On its outer surface the cartilage cap is covered with dense fibrous layer — periosteum. The hyaline cartilage cap has orderly arranged normal looking chondrocytes lying in cartilaginous matrix. Cellular foci with mild to moderate atypia may be present. At junction between the cartilage and the bony stalk, chondrocytes assume columnar arrangement and enchondral ossification takes place. Fatty or haematopoietic marrow is found between bony trabeculae of the base.
Pictures
Osteochondroma:
Osteochondroma, HE 40x (12101)
Osteochondroma:
Osteochondroma, HE 40x (12496)
Clinical signs:
Chondroma in general referrs to any benign tumour of hyalin cartilage.
Enchondroma is an intramedullary cartilaginous neoplasm consisting of lobular cartilaginous tissue within bone. Enchondromas are relatively common. Small tubular bones of the hand, feet and proximal humerus are most often affected. They are expansive and cause painfull swelling, frequently presenting with pathological fracture. Most tumours are solitary.
Periostal chondroma arises on the bone surface, without penetration into cancellous bone.
Enchondromatosis (Ollier disease) is a developmental disorder characterized by multiple enchondromas appearing in childhood.
Macroscopic appearance:
Resected tumours consist of lobular mass of blue-white, glistening hyaline cartilage. The tissue has gritty yellow areas of calcification or ossiffication.
Histology:
Cytologically benign chondrocytes reside in lacunae, are small and have round regular nucleus. Chondrocytes are orderly distributed in abundant, avascular hyalin blue-staining chondroid matrix. Enchondromas in the small bones of hands and feet are more cellular and the intervening chondroid matrix shows myxoid change. Mitoses are not detectable. At periphery, the lesion is well circumscribed.
Pictures
Enchondroma:
Enchondroma, HE 40x (12371)
Chondroma:
Chondroma, HE 40x (12419)
Chondroma:
Chondroma, HE 40x (12067)
Clinical signs:
This rare benign tumour presents in young individuals. The usual sites of involvement are epiphyseal regions of the distal and proximal femur, proximal tibia and proximal humerus.
Macroscopic appearance:
Completely resected specimens or curetted tissue fragments are grayish pink or brown, with irregular red areas of hemorrhage. Bluish foci correspond to chondroid matrix.
Histology:
Chondroblasts are uniform round to polygonal cells with slightly eosinophilic cytoplasm and sharply defined cytoplasmic borders. Round to ovoid nucleus has a longitudinal groove in the middle. Foci of immature, chondroid differentiation have eosinophilic rather than basophilic stroma. Fine pericellular calcium deposition ("chicken wire" calcification) around individual cells is characteristic of chondroblastoma. Mature cartilage is uncommon. Randomly distributed are nonneoplastic, multinucleated osteoclast-type giant cells. Low mitotic activity may be seen.
Pictures
Chondroblastoma:
Chondroblastoma, HE 40x (12416)
Chondroblastoma:
Chondroblastoma, HE 40x (12417)
Chondroblastoma:
Chondroblastoma, HE 40x (12418)
Clinical signs:
is a benign tumour characterized by spindle shaped or stellate cell distributed in lobules of abundant myxoid and chondroid stroma. Any bone may be affected, although site of prefference is proximal portion of the tibia. Presents with pain and swelling.
Macroscopic appearance:
The tissue is is firm, sharply circumscribed, gray-white or bluish.
Histology:
The tumor produces lobules, hypercellular at periphery, centers hypocellular. The abundant background stroma have myxoid, fibrous or chondroid appearance. The cells are spindle- to stellate-shaped. Mild cellular pleomorphism may be present, but mitoses are rare. Dense cellular peripheral regions contain few multinucleated osteoclast-like cells.
Pictures
Chondromyxoid fibroma:
Chondromyxoid fibroma, HE 40x (12068)
Chondromyxoid fibroma:
Chondromyxoid fibroma, HE 40x (12420)
Clinical signs:
Chondrosarcoma in general is a malignant tumour in which the neoplastic cells (chondroblasts) form purely cartilaginous matrix.
Primary (conventional) chondrosarcoma, the most common type, arises in the central portions of the previously normal skeleton, including the pelvis, humerus, and ribs. Clinical symptoms include local pain and swelling.
Secondary chondrosarcoma arises in benign precursor lesion, chondroma or osteochondroma.
Periosteal chondrosarcoma occurs on bone surface.
Macroscopic appearance:
Bulky white or blue-gray translucent tissue nodules of the primary chondrosarcoma permeate througout the medullary cavity, destroy the cortex, and extend into surrounding soft tissue. The tumour usually measures several centimeters in thickness.
Histology:
Irregularly shaped lobules of malignant cartilaginous tissue infiltrate the marrow space and permeate preexisting bony trabeculae. The cellularity is increased, chondrocytes are atypical varying in size and shape. Binucleated cells are present. Chondroid matrix may show myxoid change. Degree of cellularity, atypia and mitotic activity correlate with biological behaviour and prognosis. It is usefull to evaluate histological grade on a scale of 1 – 3. Well differentiated tumours (Grade 1) demonstrate moderate cellularity, chondrocytes have plump vesicular nuclei and inconspicuous nucleoli. Binucleated cells are sparse. Moderately differentiated (Grade 2) tumours are more cellular, nuclear atypia is more pronounced. Poorly diferentiated tumours (Grade 3) show marked cellularity, mitotic activity, prominent pleomorphism and nuclear atypia.
Pictures
Chondrosarcoma:
Chondrosarcoma, HE 40x (12069)
Chondrosarcoma:
Chondrosarcoma, HE 40x (12421)
Chondrosarcoma:
Chondrosarcoma, HE 40x (12422)Chondrosarcoma, HE 40x (12423)
Chondrosarcoma:
Chondrosarcoma, HE 40x (12424)
Clinical signs:
Osteoma may not represent a true neoplasm. It is a benign protrusion seen typically in the flat bones of the skull and face. Slowly growing osteoma may cause obstruction of the paranasal sinus cavity. Multiple osteomas in association with intestinal polyposis and soft tissue tumours are seen in patients with Gardner syndrome.
Histology:
Osteoma consists of dense, mature, lamellar bone lacking osteoblastic rims. Variants with predominantly cortical concentric pattern or trabecular bone exist.
Pictures
Osteoma:
Osteoma, HE 40x (12498)
Clinical signs:
Osteoid osteoma is a benign, painful lesion characterized by small size (usually less than 1 cm), round, clearly demarcated osteoblastic nidus surrounded by reactive sclerotic bone. Osteoid osteoma typically occurs in the cortex of long bones, particularly tibia and femur.
Histology:
The central nidus is red to tan granular, gritty tiissue, surrounded by whitish sclerotic bone. Central nidus is vascular fibrous tissue containing interconnected, ossified bone trabeculae formed by benign osteoblasts. The trabeculae of woven bone are lined with osteoblasts. The interface between the nidus and the surrounding nonneoplastic, lamellar reactive bone is abrupt.
Pictures
Osteoid osteoma:
Osteoid osteoma, HE 40x (12102)
Osteoid osteoma:
Osteoid osteoma, HE 40x (12497)
Clinical signs:
Osteoblastoma is a rare benign neoplasm that usually affects a spine. It shares similar histological features with osteoid osteoma, but the size is larger (more than 2 cm) and the zone of reactive bone formation is absent.
Histology:
Proliferating fibrovascular tissue contains osteoid trabeculae and multinucleated osteoclast-like giant cells. Osteoid trabeculae show prominent osteoblastic rimming. Osteoblasts are plump but uniform. Trabeculae are broad, well-mineralized, or narrow, poorly mineralized.
Pictures
Osteoblastoma:
Osteoblastoma, HE 40x (12494)
Pictures
Osteoblastom:
Osteoblastoma, HE 40x (12494)
Clinical signs:
Osteosarcoma is a highly malignat mesenchymal neoplasm, in which proliferating neoplastic cells produce bone matrix. It is the most common primary malignant tumour of bone. The peak incidence is in the second decade of life. Long bones of extremities, especially about the knee, are mostly affected. Osteosarcoma may present with pain, swelling or sudden fracture of the bone. Hematogenic metastasis to distant sites develope early, lungs and bones beiing the most common sites.
Conventional osteosarcoma arising as a primary intramedullary neoplasm of long bones is the most common subtype.
Teleangiectatic osteosarcoma is dominanted by cystic areas filled with blood clot. Blood filled spaces are separated by cellular septae composed of pleomorphic malignant cells with high mitotic activity. Osteoid matrix and scattered multinucleated giant cells are also present.
Secondary osteosarcoma arises in bone previously affected by Paget disease, benign tumour, infarct; postradiation osteosarcoma can develop in any irradiated bone.
Macroscopic appearance:
The conventional osteosarcoma is gray-white mass filling the medullary cavity and replacing the marrow. Destructive growth with penetration through the cortex into the neighbouring soft tissue is characteristic.
Pleomorphic tumour cells contain large hyperchromatic nuclei. Atypical mitotic figures are common. Production of amorphous, extracellular eosinophilic osteoid substance, or primitive bone trabeculae, characterizes osteoblastic osteosarcoma. Abundant malignant cartilaginous matrix is found in chondroblastic variant of osteosarcoma. Tumours with predominant atypical fibrous matrix are calles fibroblastic osteosarcoma.
Pictures
Osteosarcoma:
Osteosarcoma, HE 40x (12100)
Osteosarcoma:
Osteosarkoma, jaw, HE 40x (12500)
Osteosarcoma:
Osteosarkoma, HE 40x (12501)
Osteosarcoma:
Osteosarcoma, HE 60x (12299)
Osteosarcoma:
Osteosarcoma, HE 40x (11005)
Osteosarcoma:
Osteosarcoma, HE 40x (11006)
Clinical signs:
Ewing sarcoma is an undifferentiated, small round cell sarcoma. PNET shows features of neuroectodermal differentiation by application of light microscopy, immunohistochemistry or electron microscopy. Majority of patients are younger than 20 years. Any bone may be affected, with a predilection for diaphysis of long tubular bones. In more than 80% of cases t(11;22) (q24;q12) chromosomal translocation is detetable by genetic methods.
Histology:
The tissue is usualy soft and friable, often necrotic and haemorrhagic.
Histology:
In typical cases, classic Ewing sarcoma consists of broad sheets and large nests of uniform small roud cells with round nuclei. The cytoplams is scanty, clear or eosinophilic. The nuclei contain finely distributed chromatin. Cytoplasmatic glycogen can be demonstrated with PAS technique. Less common are tumours composed of larger, irregular cells with prominent nucleoli (atypical Ewing sarcoma). Rarely, presence of Homer-Wright rosetts may indicate neuroectodermal differentiation in PNET.
Pictures
Ewing sarcoma:
Ewing's sarcoma, HE 40x (12378)
Ewing sarcoma:
Ewing's sarcoma, HE 40x (12050)
Clinical signs:
Myeloma is the most common neoplasm of bones with predilection for bones containing hematopoietic marrow (skull, vertebrae, ribs, pelvis). The majority of patients are elderly between the ages of 50 and 80 years. Malignant plasma cells accumulate in the bone marrow and produce multicentric, osteolytic lesions (multiple myeloma). Increased levels of imunoglobulin, usually monoclonal IgG or IgA or light chains can be detected in the serum.
A neoplasm of plasma cells thas produces single osseous lesion is called solitary myeloma.
Macroscopic appearance:
Small biopsy specimens or curettings are mottled red-gray soft tissue fragments.
Histology:
Myeloma consists of polygonal neoplastic plasma cells arranged in sheets with little capillary stroma. The cells have an excentric round nucleus with clustered chromatin at periphery, giving a cartwheel appearance. Binucleated cell are also present. In less mature lesions the cells show blast-like appearance with nuclear pleomorphism and conspicuous nucleoli.
Pictures
Myeloma of the bone, HE and light chains kappa and lambda:
Myeloma of the bone, HE 40x (12480)Myeloma of the bone, kappa 40x (12481)Myeloma of the bone, lambda 40x (12482)
Myeloma of the bone:
Myeloma of the bone, HE 40x (12483)
Clinical signs:
It is a tumefaction producing neoplastic growth within bone composed of malignat lymphoid cells. Any bone with persistent red marrow may be affected, most commonly femur.
Pain and palpable mass are usual symptoms. Lymphoma destroys normal bone with mixed areas of variable osteolysis and sclerosis.
Primary lymphoma of bone refers to those cases presenting as a solitary bone tumor wihout any other osseous or extraosseous (visceral) involvement, with exception of regional lymph node extension.
Secondary bone lymphoma can be regarded in patients presenting with lyphoma of other sites in whom secondary bone localization of lymphoma is disclosed by biopsy.
The differentiation of primary versus secondary bone involvement is of major prognostic importance.
Histology:
Lymphomas of bone are classified similarly to lymph node counterparts. Diffuse large-B-cell lymphoma is the most frequent type. The neoplastic cells permeate marrow and bone structures. The cells are large but cellular polymorphism due to considerable variability in size and shape is common. Many cell contain irregular nuclei with prominent nucleoli. Crushing artefacts, fibrosis and spindling may cause diagnostic difficulties. In such cases, stain with CD20 is helpful in differentiation from sarcoma.
Clinical signs:
Is a locally aggressive, osteolytic neoplasm characterized by numerous multinucleated giant cells. Typical site of involvement is epiphysis of long bones. Giant cell tumour rarely gives rise to pulmonary metastasis.
Macroscopic appearance:
Usually removed by curettage, the tissue fragments are soft, tan and fleshy, sometimes haemorrhagic.
Histology:
Giant cel tumour contains large number of giant cells of osteoclast type diffusely distributed on the background population of mononuclear cells. Neoplastic mononuclear cells are polygonal or spindle shaped; mitotic figures are frequent. Multinucleated giant cells are nonneoplastic. The nuclei are numerous, sometimes hundred or more. Storiform fibrous areas with foamy or hemosiderin-laden macrophages, and foci of reactive woven bone may be present.
Pictures
Giant cell tumor of the bone:
Giant cell tumor of the bone, HE 40x (12493)Giant cell tumor of the bone, CD68 40x (12492)
Giant cell tumor of the bone:
Giant cell tumor of the bone, HE 40x (12099)
Clinical signs:
Chordoma is a low grade malignant neoplasm restricted to the axial skeleton, region of embryonic remants of the notochord. Solitary, destructive lesions arise in the cervical and lumbar spine.
Pictures
Chordoma, CT, MRI:
Chordoma, clivus, CT, X-ray (71836)Chordoma, clivus, MRI, sagittal plane, X-ray (71837)Chordoma, clivus, MRI, transversal scan, X-ray (71838)
Macroscopic appearance:
Chordoma presents as lobulated, soft, gelatinous, translucent mass.
Pictures
Chordoma, brain and rib:
Chordoma (brain, rib), Macro, autopsy (70862)
Histology:
Chordoma has lobulated appearance, with fibrous bands separating the lobules. Lobules contain cells arranged in cords, sheets or trabeculae, lying within a myxoid stroma. The tumour cells have round uniform nuclei and abundant pale multivacuolated cytoplasm. These highly vacuolated cells are classically called "physaliphorous cells". Chordoma cells express cytokeratin.
Pictures
Chordoma:
Chordoma, HE 40x (12425)
Aggressive chordoma:
Chordoma, HE 40x (72105)Chordoma, AE13 40x (72032)
Clinical signs:
Intraosseous hemangioma is a benign vascular neoplasm or developmental malformation of endothelial cell origin. Vertebral bodies and skull are the sites involved most commonly.
Macroscopic appearance:
Haemangiomas are soft, dark red.
Histology:
The vascular channels of intraosseous hemangioma replace the normal marrow elements. Cavernous hemangioma shows broad thin-walled blood vessels, lined by single layer of benign endotelial cells and filled with blood. An admixure of smaller vascular spaces of capillary hemangioma indicate mixed capilary and cavernous lesion.
Pictures
Hemangioma of the bone:
Hemangioma of the bone, HE 40x (12061)
Clinical signs:
This is a rare malignat counterpart to relatively common intraosseous hemangioma. The axial skeleton and long tubular bones are affectes in most cases. Angiosarcoma develops lytic lesions.
Macroscopic appearance:
Grossly, the tumor is usually bloody, dark red mass eroding cortex with extension into adjacent tissue.
Histology:
Skeletal angiosarcoma is composed of more or less well formed anastomosing vascular channels. Neoplastic endothelial cell may form intraluminal tufts or micropapilae. Enlarged, atypical endothelial lining cells have hyperchromatic or vesicular nuclei containing nucleoli. Nuclear to cytoplasmatic ratio is high. Poorly differentiated angiosarcoma is more cellular, mitotically active and contains few discernible lumens. Histological degree of differentiation has a prognotic value.
Clinical signs:
Is a low-grade malignant, primary intraosseous epithelial neoplasm with a marked predilection for the tibia. Adamantinoma may be associated with osteofibrous dysplasia.
Macroscopic appearance:
Adamantinoma is a solid, lobulated tumor, with firm or granular consistency. The colour is gray or white. Cystic spaces may be present.
Histology:
Variety of epithelial elements are situated in a fibrous stroma. Epithelial differentiation may assume basaloid, tubular or squamous patterns. Positive immunohistochemical stain for cytokeratin helps to identify the epithelial component. A special morphologic pattern, so called osteofibrous dysplasia-like adamantioma is difficult to differentiate from benign condition, osteofibrous dysplasia.
Pictures
Adamantinoma, HE and AE1/3:
Adamantinoma, HE 40x (12317)Adamantinoma, AE13 40x (12316)
Adamantinoma and metastasis to the lung:
Adamantinoma of the bone, HE 40x (12645)Adamantinoma of the bone, metastasis, HE 40x (12646)
OFD-like adamantinoma:
OFD adamantinoma of the bone, HE 40x (12718)
Clinical signs:
Malignant tumours, often common carcinomas, originating from another sites (lung, breast, prostate, kidney, thyroid) are the most common malignacies affecting the skeleton. The lumbar spine and proximal femur are favourit sites of involvement. The deposits may be lytic or osteoblastic.
Histology:
Adenoarcinomas usually retain morphological similarities to the primary tumour. Immunohistochemistry is usefull in identifying occult primary sites. Metastatic squamous cell carcinomas from different sites of origin have common similar histological appearances.
Pictures
Metastasis of Grawitz carcinoma of the kidney to the bone:
Grawitz carcinoma, metastasis of the bone, HE 40x (12093)
Hepatocellular carcinoma, metastasis:
Hepatocellular carcinoma, metastasis, HE 40x (12474)