Bone
Bone forming tumors (not osteosarcoma)
Osteoblastoma
Copyright: 2003-2019, PathologyOutlines.com, Inc.
PubMed Search: Osteoblastoma[title]
Related topics: Aggressive osteoblastoma
Bone forming tumors (not osteosarcoma)
Osteoblastoma
Author: David R. Lucas, M.D.
Topic Completed: 1 August 2013
Minor changes: 5 July 2019
Copyright: 2003-2019, PathologyOutlines.com, Inc.
PubMed Search: Osteoblastoma[title]
Related topics: Aggressive osteoblastoma
Table of Contents
Definition / general | Terminology | Sites | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Electron microscopy description | Differential diagnosis | Additional referencesCite this page: Lucas DR. Osteoblastoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/boneosteoblastoma.html. Accessed May 30th, 2020.
Definition / general
- Benign, bone forming tumor comprised of anastomosing trabeculae of osteoid and woven bone rimmed by osteoblasts
- Rare; 1% of primary bone tumors
Terminology
- Also called giant osteoid osteoma
Sites
- Wide skeletal distribution
- 1 / 3 spine and sacrum
Clinical features
- Progressive pain, not as intense as with osteoid osteoma
- Spinal tumors have neurological findings and scoliosis
- Rarely presents with fever, weight loss, generalized periostitis (“toxic osteoblastoma”, Am J Surg Pathol 1979;3:463)
Diagnosis
- Radiographic correlation often helpful
Radiology description
- Demarcated bone tumor with intralesional ossification
- Mostly nondestructive growth
- Some have central nidus or nidi
- Tumors with secondary ABC changes (aneurysmal bone cyst) are expansile
- Spinal tumors originate in dorsal elements, may secondarily involve vertebral body
- Up to 25% of radiographs are suspicious for malignancy (AJR Am J Roentgenol 1976;126:321)
Radiology images
AFIP images
Pubic ramus expanded, cortex thinned
Contributed by Dr. Mark R. Wick
Talus
Talus MRI
Contributed by Dr. David R. Lucas
T7 osteoblastoma with central nidus
Iliac osteoblastoma with sclerotic rim
Rib osteoblastoma suspicious for malignancy
Large periosteal osteoblastoma of femur
Great toe osteoblastoma
Osteoblastoma of tooth root
Images hosted on other servers:
Sphenoid osteoblastoma
Prognostic factors
- 20% local recurrence
- Tumor localized near central neural axis have greater morbility and mortality
Case reports
- 11 year old girl with skull base osteoblastoma (Skull Base 2009;19:437)
- 13 year old boy with spinal osteoblastoma (Arch Pathol Lab Med 2010;134:1460)
Treatment
- Curettage, en bloc resection
Gross description
- Mostly curetted gritty, red fragments of osteoblastoma
- Intact tumors well demarcated with scalloped edges
- Often hemorrhagic
- One or more nidi
Gross images
AFIP images
Osteoblastoma of ilium
Contributed by Dr. Mark R. Wick
Atypical type
Contributed by Dr. David R. Lucas
Osteoblastoma of clavicle
blastoma with
central nidus
involving pedicle
Images hosted on other servers:
Intracortical osteoblastoma of tibia
Microscopic (histologic) description
- Anastomosing trabeculae of osteoid and woven bone
- Rimmed by single layer of benign activated osteoblasts
- Numerous osteoclasts
- Loose fibrovascular stroma between bone trabeculae
- Intralesional hemorrhage and secondary ABC common
- Does not permeate adjacent host trabecular bone
- Often pagetoid reversal lines
- Central nidus of dense woven bone in some
- Low mitotic rate
- Rare tumors with cartilaginous matrix
- Rare tumors with degenerative atypia (pseudomalignant osteoblastoma)
Microscopic (histologic) images
AFIP images
Various images
Contributed by Dr. Mark R. Wick
Atypical type
Atypical type with epithelioid osteoblasts
Talus
Contributed by Dr. David R. Lucas
Osteoblastoma with cartilaginous matrix
Demarcated tumor
Activated osteoblasts
Anastomosing trabeculae
Central nidus of sclerotic woven bone
Solid area of an osteoblastoma
Osteoblastoma high power
Degenerative atypia
Images hosted on other servers:
Various images
Cytology description
- Large osteoblasts with eccentric cytoplasm and perinuclear hof and large vesicular nuclei with prominent nucleoli
- Osteoclastic giant cells
- Osteoid matrix
Cytology images
Contributed by Dr. David R. Lucas
Cytology smears
A and B: Plasmacytoid appearance of osteoblast and multinucleated osteoclast cells (Diff-Quik, 3400)
C: Osteoblasts and banal spindled cells (Papanicolaou, 3400)
D: Cell block exhibiting osteoid with osteoblasts (H&E, 3100)
Electron microscopy description
- Children and young adults
- Mean age 20 years, wide age range (6 - 75 years)
- 60% female (2:3 male:female ratio)
Differential diagnosis
- Aggressive osteoblastoma
- Aneurysmal bone cyst
- Giant cell tumor
- Osteoblastoma-like osteosarcoma
- Osteoid osteoma
- Osteoma with osteoblastoma like features (Arch Pathol Lab Med 2009;133:1587)
Additional references
