Rare tumour presenting as a cystic lesion in an infant

Area of Science:

• Paediatric Oncology
• Dermatopathology
• Surgical Pathology

Background:

• Plexiform fibrohistiocytic tumours (PFHT) are rare neoplasms typically affecting the extremities.
• Presentation in the paediatric population, particularly as a midline back mass, is exceptionally uncommon.

Purpose of the Study:

• To report a rare case of PFHT in an infant presenting as a subcutaneous back mass.
• To emphasize the diagnostic considerations for paediatric cystic masses.

Main Methods:

• Clinical presentation and imaging findings.
• Surgical wide excision and subsequent re-excision.
• Histopathological examination for definitive diagnosis.

Main Results:

• Histopathology confirmed a plexiform fibrohistiocytic tumour with initially positive margins.
• Re-excision successfully achieved clear margins.
• The tumour was located subcutaneously in the upper midline back, overlying the spine.

Conclusions:

• This case underscores the importance of including PFHT in the differential diagnosis of paediatric subcutaneous and cystic masses.
• Early and accurate diagnosis through histopathology is crucial for appropriate management and complete tumour resection.