Bone Cyst (Aneurysmal Bone Cyst and Solitary Bone Cyst), Cytological Findings

Synonyms

Aneurysmal bone cyst (ABC); Primary aneurysmal bone cyst; Simple bone cyst; Solitary bone cyst (SBC); Unicameral bone cyst

Definition

• 1. ABC: benign, multilocular cyst with rich capillary tissue with a locally destructive growth.

• 2. SBC: benign unilocular cyst with serous fluid and no tumor tissue.

Clinical Features

• Incidence

  • 1. ABC: 2.5% of all primary bone tumors.

  • 2. SBC: relatively common.

• Age

  • 1. ABC: most patients are younger than 20 years.

  • 2. SBC: a majority of patients are younger than 15 years.

• Sex

  • 1. ABC: no sex predilection.

  • 2. SBC: males dominate (2:1).

• Site

  • 1. ABC: all bones can be affected, but the bones around the knee and the vertebral column are overrepresented.

  • 2. SBC: the humerus and femur dominate but most bones can present the lesion.

• Treatment

  • 1. ABC: curettage and bone grafting.

  • 2. SBC: curettage and bone grafting, instillations.

• Outcome

  • 1. ABC: most patients are cured.

  • 2. SBC: most patients are cured.

Microscopy

• 1....