A recent case report published in the Journal of Orthopaedic Case Reports described a woman who developed two spine fractures even though her bone density scans were normal. The patient, who had a 20-year history of cutaneous mastocytosisMastocytosis Rare disease caused by the buildup of mast cells. Cutaneous mastocytosis primarily affects the skin and is more common in children, while systemic mastocytosis affects internal organs and is more common in adults., was later diagnosed with indolent systemic mastocytosis (SM).
The case highlights how indolent SMIndolent SM A subtype of nonadvanced SM caused by the abnormal accumulation of mast cells in the bone marrow and other organs. Indolent SM accounts for around 90% of SM cases. may affect bone strength in ways a standard density scan may not fully capture. Bone density scans measure the amount of mineral in bone, but they may not show changes in bone quality or internal structure. The authors explained that substances released by mast cells may increase bone breakdown, interfere with normal bone repair and weaken the bone’s architecture.
Read more about SM signs and symptoms
The patient was a 56-year-old woman with cutaneous mastocytosis and chronically elevated serum tryptaseTryptase A protein enzyme that is primarily produced by mast cells and stored in small pockets within the cells, known as granules. High levels of tryptase are a key indicator of SM., a marker of mast cellMast cell A type of white blood cell produced in the bone marrow. They help defend against infections and play a key role in allergic reactions. In SM, mast cells become overactive and build up throughout the body. activity. At first, she reported sudden mid-back pain after lifting a light object. Imaging showed an acute compression fracture in the spine, even though her bone density scan was normal.
Following that, the woman underwent kyphoplasty, a procedure used to stabilize compression fractures, and her pain improved. After 10 weeks, she developed severe low-back pain without trauma. Magnetic resonance imaging (MRI) showed another acute compression fracture in the spine.
Because the second fracture occurred so soon after the first and without clear trauma, clinicians performed a bone biopsy during the second kyphoplasty. The biopsy showed abnormal mast cell clusters in the bone, and molecular testing detected the KIT D816V mutation, a genetic change commonly found in SM. A later bone marrow biopsyBone marrow biopsy A procedure to collect a sample of bone marrow using a needle. Often used to examine the characteristics of mast cells and diagnose SM. confirmed the diagnosis of indolent SM.
After the diagnosis, the patient began intravenous bisphosphonate therapy and was followed by hematology and metabolic bone disease specialists. By 12 months, she was pain-free and back to her usual activities. Follow-up imaging showed no new fractures or further collapse of the affected vertebrae.
For people with SM, the case may be a reminder to report new or unexplained back pain, especially after little or no trauma. The authors noted that identifying disease early can mean better care: “Early recognition allows implementation of fracture prevention strategies, antiresorptive therapy, and multidisciplinary monitoring to mitigate long-term skeletal morbidity,” they noted.
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