Mast cell sarcoma: new cases and literature review

Abstract

Mast cell sarcoma (MCS) is a rare form of mastocytosis characterized by the presence of solid tumor(s) comprising malignant mast cells that harbor destructive infiltration capability and metastatic potential. Here, we present an extensive literature review and report on 23 cases of MCS, including 3 new cases from the French National Reference Center for Mastocytosis. From our analysis, it appears that MCS can occur at any age. It can manifest de novo or, to a lesser extent, may evolve from a previously established mastocytosis. Bone tumor is a frequent manifestation, and symptoms of mast cell activation are rare. Histological diagnosis can be difficult because MCS is frequently composed of highly atypical neoplastic mast cells and can thus mimic other tumors. Unexpectedly, the canonical KIT D816V mutation is found in only 21% of MCS; therefore, complete KIT gene sequencing is required. The prognosis of patients with MCS is poor, with a median survival time of less than 18 months, and progression to mast cell leukemia is not unusual. Because conventional chemotherapies usually fail, the role of targeted therapies and bone marrow transplantation warrants further investigation in such aggressive neoplasms.

Elevated Serum Tryptase in Non-Anaphylaxis Cases: A Concise Review

“…MC sarcoma is a rare and aggressive clonal MC disorder that commonly affects bone. One systematic analysis of 23 cases found a markedly elevated median tryptase of 236 μg/L [54].…”

Mastocytosis – pathogenesis, clinical manifestation and treatment

“…While the highly atypical cells can histologically mimic other tumors , mast cell tryptase levels, which are frequently markedly elevated, point to the correct diagnosis. Symptoms related to mast cell mediators such as fever, flushing, diarrhea, and tachycardia occur in only one‐third of all cases . These tumors frequently occur de novo in bone, more rarely in the oropharyngeal and gastrointestinal tract, the lymph nodes, skin, liver, spleen, or other organs.…”

“…Progression to mast cell leukemia is possible. The D816V mutation, which is common in other forms of mastocytosis, is found in only 21 % of cases .…”

Mastozytose – Pathogenese, Klinik und Therapie

“…Hinweisend kann die oft deutlich erhöhte Mastzelltryptase sein. Eine Mastzell‐Mediatorsymptomatik wie Fieber, Flush, Diarrhoe, Tachykardie zeigt sich in nur in einem Drittel der Fälle . Die Tumore entstehen häufig de novo im Knochen, seltener im Oro‐Pharyngeal‐ und Gastrointestinaltrakt, den Lymphknoten, der Haut, in Leber oder Milz oder anderen Organen.…”

“…Sie können in eine Mastzellleukämie übergehen. Die, bei anderen Mastozytose‐Formen häufige, D816V‐Mutation, findet sich nur in 21 % der Fälle [.…”