Pathology of tumours

Question 1

Radiolucent with increasing density towards periphery.
Destruction of medullary cavity and adjacent cortex.
May expand into soft tissue.

Answer 1

Giant cell tumour

Question 2

Multinucleated giant cells in a sea of round to oval mononuclear cells

Answer 2

Giant cell tumour

Question 3

Irregular spicules of mineralised bone and osteoid surrounded by osteoblasts

Vascular stroma with pleomorphic spindle cells

Osteoid and woven bone are seen

Answer 3

Osteoblastoma

Question 4

Lobules and fibrous septa. The malignant cell has eosinophilic cytoplasm & prominent vacuoles of mucus push the nuclei to the side.

Answer 4

Chordoma

Question 5

Malignant osteoblasts forming osteoid

Young adults; 60%

Answer 5

Osteosarcoma

Question 6

Osteoid production is essential for diagnosis.

Nuclear atypia, hyperchromasia and a high mitotic rate.

There are three histological variants of conventional osteosarcoma: osteoblastic, chondroblastic, and fibroblastic..

Answer 6

Osteosarcoma

Question 7

Closely packed polygonal cells plus areas of immature chondroid

Answer 7

Chondroblastoma

Question 8

Chicken wire calcification

Answer 8

Chondroblastoma

Question 9

Spherical and well-defined osteolytic foci, sometimes extending into the subarticular bone, joint space or metaphysis

Answer 9

Chondroblastoma

Question 10

Nidus consists of osteoid and woven bone surrounded by osteoblasts.
Central nidus of an osteoid osteoma composed of irregular reactive new bone

Answer 10

Osteoid osteoma

Question 11

Radiolucent nidus surrounded by reactive sclerosis in cortex of bone

Answer 11

Osteoid osteoma