Lingual Alveolar Soft Part Sarcoma in a 1-Year-Old Infant: Youngest Reported Case With Characteristic ASPSCR1-TFE3...

Area of Science:

• Pediatric Oncology
• Molecular Pathology
• Rare Cancers

Background:

• Alveolar soft part sarcoma (ASPS) is a rare non-rhabdomyosarcomatous soft tissue sarcoma (NRSTS).
• ASPS is characterized by the specific translocation t(X;17)(p11.2;q25), leading to the ASPSCR1-TFE3 fusion oncogene.
• Complete surgical resection is the primary curative treatment for ASPS.

Observation:

• An 11-month-old female infant presented with a tongue lesion mimicking infantile hemangioma.
• The lesion enlarged despite initial surveillance, prompting a biopsy at 17 months.
• Histopathology revealed epithelioid tumor cells with pseudoalveolar spaces and PAS-D inclusions.

Findings:

• Immunostaining confirmed nuclear TFE-3 positivity.
• Real-time quantitative PCR identified the characteristic ASPSCR1-TFE3 fusion transcript.
• This case represents the youngest patient with a molecularly confirmed ASPS diagnosis.

Implications:

• Highlights the importance of re-evaluating initial diagnoses when clinical progression deviates from expectations.
• Emphasizes the critical role of multidisciplinary discussion and early biopsy in diagnosing rare pediatric tumors.
• Underscores the need for timely surgical intervention and surveillance for pediatric soft tissue sarcomas.