Sarcomas and Multiple Myeloma: Types and Clinical Features

Sarcomas

• Fibrosarcoma: a rapidly growing swelling with a herringbone pattern of malignant fibroblasts, thin-walled dilated blood vessels in poorly differentiated tumors
• Fibrosarcoma classification:
  • Well-differentiated type (low grade): resembles normal parent tissue, production of collagen, increase intercellular matrix, rare mitoses
  • Moderately differentiated type (intermediate grade): less resemblance to parent tissue, less production of collagen, intermediate production of intercellular matrix, moderate mitosis
  • Poorly differentiated type (high grade): no resemblance to parent tissue, less production of collagen, decreasing intercellular matrix, increasing mitosis

Osteosarcoma

• Character: painful, rapidly growing swelling of the involved bone, producing bulky lesion, facial deformity, paresthesia, looseness of teeth, toothache, bleeding, nasal obstruction, pathologic fracture is common
• Types according to radiographs:
  • Osteolytic type (destructive type): tumors with little tumor bone, appear as an irregular radiolucency
  • Osteoblastic or sclerosing type: much tumor bone produced, resulting in sun-ray appearance
• Types according to histologic features:
  • Osteoblastic
  • Chondroblastic
  • Fibroblastic
  • Telangiectatic (osteogenic sarcoma)

Chondrosarcoma

• Arises from mesenchymal stem cells
• Site: ant part of maxilla, remnants of Meckel's cartilage
• Radiographic picture: Garrington sign (widening of the periodontal ligament), irregular radiolucency with radiopacities
• Histopathology: highly cellular, binucleated cells, lacunae contain more than two cells, pleomorphism, hyperchromatism

Ewing's Sarcoma

• Clinical features: occurs in children and young adults, pain, swelling, loosening of teeth, mucosa ulcerates, leucocytosis, fever, and raised ESR and anemia
• Mic. Endemic type: common in Africa, affects children of 7 years old
• Mic. Non-Endemic type: common in the USA, affects children of 11 years old
• Histologic features: monotonous overgrowth of undifferentiated monomorphic lymphoreticular cells, macrophages with clear cytoplasm scattered uniformly throughout the tumor, producing the characteristic starry sky appearance

Multiple Myeloma

• Definition: a malignant tumor of bone, arising from cells of bone marrow similar to plasma cells
• Etiology: unknown, risk factors include obesity, radiation exposure, family history, and certain chemicals
• Clinical features: age 40-70 years, female > male, sites: vertebrae, ribs, skull, ends of long bones, and jaw bones (mandible > maxilla), rapidly growing painful swelling, expansion of the bone, numbness, mobility of teeth, hemorrhage, and pathologic fractures
• Histopathology: cells resemble lymphocytes but are larger, intracellular glycogen is noticed, cells are in lobules or sheets

Kaposi's Sarcoma

• Definition: a sarcoma caused by HHV-8 in AIDS patients (immunodeficiency)
• Clinical features: four sub-types:
  • Classic Kaposi's sarcoma: affects older men in regions where KSHV is highly prevalent, slow-growing, and most often affects only the legs
  • Endemic Kaposi's sarcoma: most common in Sub-Saharan Africa, more aggressive in children
  • Immunosuppression therapy-related Kaposi's sarcoma: occurs in people following organ transplantation, mostly affects the skin
  • Epidemic Kaposi's sarcoma: occurs in people with AIDS, many parts of the body can be affected
• Histopathology: proliferating malignant spindle cells, slit-like vascular channels

African Jaw Lymphoma (Burkitt's Lymphoma)

• Definition: a form of malignant lymphoma in which cancer starts in immune cells called B lymphocytes
• Clinical features: age 2-14 years, site: mandible, maxilla, ethmoid and sphenoid sinuses, orbit, and visceral organs
• Types: Endemic and Non-Endemic