Heterotopic ossification
Heterotopic ossification is an uncommon pathology specimen that may be considered a ditzel.
General
- Definition of heterotopic ossification: bone formation in soft tissue.[1]
- Injury at site.
- May be seen in the context of tetraplegia.
Clinical:[1]
- +/-Joint stiffness.
- +/-Swelling.
- +/-Pain.
Gross
- Firm nodule.
Microscopic
Features:
- Lamellar bone - has layering/lines (best seen with polarized light).
- +/-Skeletal muscle (within the marrow space).
DDx:
- Myositis ossificans - inflammation, cellular.
- Osteosarcoma, extraskeletal.
- Osteochrondroma - at joint, has cartilage.[citation needed]
- Pilomatricoma - may be extensively ossified.[2]
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Lesion, Distal Phalanx of Right Little Finger, Excision: - Dermal ossification without cartilage in benign skin with a thick keratin layer. - NEGATIVE for evidence of malignancy.
Block letters
LESION ("HETEROTOPIC OSSIFICATION"), RIGHT FEMUR, EXCISION:
- BONE -- CONSISTENT WITH MUSCLE HETEROTOPIC OSSIFICATION.
- NEGATIVE FOR MALIGNANCY.
Micro
The sections show laminar bone with a marrow space containing adipose tissue and benign skeletal muscle. The osteocytes show no nuclear atypia. No mitotic activity is appreciated.
See also
References
- ↑ 1.0 1.1 Leblanc, E.; Trensz, F.; Haroun, S.; Drouin, G.; Bergeron, E.; Penton, CM.; Montanaro, F.; Roux, S. et al. (Jun 2011). "BMP-9-induced muscle heterotopic ossification requires changes to the skeletal muscle microenvironment.". J Bone Miner Res 26 (6): 1166-77. doi:10.1002/jbmr.311. PMID 21611960.
- ↑ Ioannidis, O.; Stavrakis, T.; Cheva, A.; Papadimitriou, N.; Kotronis, A.; Kakoutis, E.; Makrantonakis, N. (2010). "Pilomatricoma of the arm with extensive ossification.". Adv Med Sci 55 (2): 340-2. doi:10.2478/v10039-010-0010-y. PMID 20439187.