Giant subperiosteal hematoma

A 22-year-old patient, who had been bedridden since childhood following mitochondrial encephalopathy was hospitalized for a pulmonary infection. Following the discovery of a voluminous painless tumefaction of the left thigh, lower extremity Doppler examination and X-rays showed a well-defined soft-tissue mass surrounding the femur, with no signs of hypervascularization on the Doppler sonography. A complementary computed tomography scan revealed an old, non-displaced metaphyseal fracture associated with extensive subperiosteal hematoma of the femur (Figure 1). The eccentric ossification surrounding the mass encompassed the femoral shaft lifting muscles off the cortex to give an appearance of periosteal stripping as shown on three-dimensional reconstructions (Figure 2). Laboratory findings showed normal calcium levels with secondary hyperparathyroidism because of vitamin D insufficiency (25-OH-D: 10.2 ng/mL). The level of vitamins A and C was normal as were the coagulation assays.

Figure 1 Axial computed tomography showing ossifying periosteum lifts the muscles off the cortex of the left femur, demonstrating subperiosteal stripping consistent with ossifying subperiosteal hemorrhage (arrows).

Figure 2 Three-dimensional computed tomography reconstructions confirming that the ectopic ossification is longitudinal, eccentrically placed, well circumscribed, and not completely encircling the shaft corresponding to ossifying subperiosteal hemorrhage.

These pseudo-tumoral forms of subperiosteal hematoma are more often described in young patients with severe hereditary neurological disorders (1), which are considered to cause delayed bone maturation and looseness of the connection between the periosteum and the underlying bone (2). In cases of minor trauma or unrecognized fracture, massive subperiosteal haemorrhage may then occur, causing progressive elevation of the abnormally loose periosteum.

Acknowledgements

None.

Footnote

Conflicts of Interest: The authors have no conflicts of interest to declare.

Informed Consent: Written informed consent was obtained from the patient for publication of this manuscript and any accompanying images.

References

1. Sakurai A, Masuda T, Yoshiba T, Hanaoka T, Kaneko K. Radiological features of an ossifying subperiosteal hematoma in a patient with severe motor and intellectual disability. J Orthop Sci 2011;16:334-7. [Crossref] [PubMed]
2. Steenbrugge F, Poffyn B, Uyttendaele D, Verdonk R, Verstraete K. Neurofibromatosis, gigantism, elephantiasis neuromatosa and recurrent massive subperiosteal hematoma: a new case report and review of 7 case reports from the literature. Acta Orthop Belg 2001;67:168-72. [PubMed]