Diagnostic work-up of lipomatous tumors: a decision-making analysis among European sarcoma centers

Lipomatous soft-tissue tumors present a diagnostic burden. The aim of this work was to compare standard operating procedures (SOPs) for the diagnostic management of lipomatous soft-tissue tumors among European academic centers.

Experts of the Soft Tissue and Bone Sarcoma Group of the European Organization for Research and Treatment of Cancer were asked for their SOPs in the diagnosis of adipocytic soft-tissue tumors in an otherwise healthy patient. The answers were converted to decision trees and subsequently compared using the objective consensus methodology. Mediastinal and retroperitoneal lipomatous tumors were excluded from the analysis.

The highest consensus (93%) among fourteen institutions was noted for evaluation with core needle biopsy (CNB) as SOP for lipomatous tumors located deep in tissue exceeding 7 cm and tumor-associated symptoms. Evaluation of heterogeneous features on imaging by CNB usually showed a consensus rate of at least 75%. Consensus was less likely for lipomatous tumors without symptoms or heterogeneous features. In these settings, CNB and follow-up were almost equally recommended. For lipomatous tumors smaller than 3 cm, without growth or symptoms, no localization in the trunk, and homogeneous imaging features, a consensus rate of 71% was achieved for follow-up.

SOPs for diagnostic work-up of lipomatous tumors varied despite their geographical proximity. The highest consensus for biopsy was for deep large tumors with associated symptoms. For follow-up, consensus was shown for small homogenous tumors outside the trunk, without growth or symptoms. Consensus on resection involved homogeneous deeply located small tumors outside the trunk with growth and symptoms.

This study identifies the decision-making criteria with the highest consensus rate among participating academic sarcoma centers in diagnosing lipomatous tumors: tumors located deep in the tissue, a tumor size exceeding 7 cm, and associated symptoms emerge as pivotal criteria.

Standard operating procedures for diagnostic work-up of lipomatous tumors among fourteen sarcoma centers were analyzed. Identified diagnostic criteria are: imaging features, size, growth, symptoms, superficial and trunk location. The highest consensus concerned recommending biopsies for deep tumors > 7 cm with associated symptoms.