TOPLINE:

Patients with indolent systemic mastocytosis (ISM) had more vertebral fractures, particularly biconcave vertebral fractures, than those with primary osteoporosis.

METHODOLOGY:

• Researchers evaluated the morphology of vertebral fractures in adults with ISM enrolled from two centres in Italy and assessed its diagnostic value compared with primary osteoporosis.
• They included 66 adults, comprising 22 patients with ISM (mean age, 68 years; 68% women) and 44 patients with primary osteoporosis (mean age, 77 years; 93% women).
• ISM was diagnosed according to the World Health Organization and International Consensus Classification criteria, with at least one vertebral fracture; patients with primary osteopenia/osteoporosis had a bone mineral density T score ≤ -2.0, at least two vertebral fractures, and normal serum tryptase without suspected ISM.
• Clinical, densitometric, and laboratory data, including bone mineral density and serum tryptase levels, were collected; vertebral fractures were evaluated from the T4 to L4 segment on lateral spine radiographs and classified as wedge or biconcave.
• The receiver operating characteristic (ROC) curve analysis evaluated the ability of vertebral fracture-related variables to distinguish ISM from primary osteoporosis, with additional propensity score matching for age and sex.

TAKEAWAY:

• Patients with ISM had more vertebral fractures than those with primary osteoporosis (median, 4 vs 3; P = .039).
• Patients with ISM had a higher number (median, 3 vs 1) and proportion (80% vs 22%) of biconcave vertebral fractures than those with primary osteoporosis (P < .001 for both).
• The ROC analysis confirmed that the number of biconcave vertebral fractures (area under the curve [AUC], 0.878) and their proportion (AUC, 0.919) effectively distinguished ISM from primary osteoporosis (P < .001 for both).
• In a propensity score-matched analysis including 15 patients each with ISM and primary osteoporosis, both the number of biconcave vertebral fractures and their percentage maintained good discriminatory ability (AUC, 0.916 and 0.893, respectively; P < .001 for both).

IN PRACTICE:

"Our findings highlight the diagnostic relevance of analysing VFx [vertebral fracture] morphology in the work-up of bone fragility," the authors wrote. "Incorporating this parameter into existing diagnostic pathways may help reduce diagnostic delays, prevent misclassification as primary osteoporosis, and guide more appropriate therapeutic decision-making in this high-risk population," they added.

SOURCE:

This study was led by Gaetano Paride Arcidiacono, University of Padova, Padua, Italy. It was published online on December 10, 2025, in Osteoporosis International.

LIMITATIONS:

The study's small sample size may have limited generalisability. Age and sex differences between the two groups may have influenced the results. The mechanism underlying biconcave fracture morphology in SM remains unclear.

DISCLOSURES:

Open access funding was provided by Università degli Studi di Padova within the CRUI-CARE Agreement. The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.