Pseudoendocrine sarcoma: a rare new entity with unique radiologic and pathologic/molecular characteristics

Area of Science:

• Oncology
• Pathology
• Radiology

Background:

• Pseudoendocrine sarcoma is a rare intermediate-grade sarcoma with uncertain phenotype.
• It typically presents in paraspinal locations in older patients, mimicking endocrine tumors.
• A unique CTNNB1 point mutation is characteristic of this entity.

Purpose of the Study:

• To correlate radiologic imaging with pathologic features of pseudoendocrine sarcoma.
• To present a unique case with new morphologic observations.
• To report on the second-ever identified CTNNB1 hotspot mutation in this rare sarcoma.

Main Methods:

• Case report detailing radiologic and pathologic findings.
• Review of existing literature on pseudoendocrine sarcoma.
• Genetic analysis for CTNNB1 mutation.

Main Results:

• The case demonstrates a palpable, painful chest wall/paraspinal pseudoendocrine sarcoma.
• New morphologic observations were noted in this patient.
• This case represents the oldest patient reported with this specific tumor location and the second case with the characteristic CTNNB1 hotspot mutation.

Conclusions:

• This report enhances understanding of pseudoendocrine sarcoma by correlating imaging and pathology.
• It highlights the importance of recognizing this rare entity, particularly its distinctive CTNNB1 mutation.
• Further research is needed to fully elucidate the nature and behavior of pseudoendocrine sarcoma.