Aggressive Tongue Adenocarcinoma: Cystic Metastasis Paradox

Anterior tongue adenocarcinomas are exceptionally rare. This case demonstrates a high-grade non-intestinal subtype (CK7+/CDX2−/p40−) mimicking benign cystic lesions, challenging conventional diagnostic paradigms. A 48-year-old male presented with a 5-cm painless ventral tongue mass. Aspiration yielded serosanguinous fluid (no cytology performed). Wide excision confirmed high-grade non-intestinal adenocarcinoma (pT3N0, CK7+/CDX2−/p40−). Adjuvant therapy was declined. At 6 months, local recurrence prompted re-excision with bilateral neck dissection, revealing pT3N1 disease (1/20 nodes positive). Postoperative radiotherapy was again refused. 6 months later, CT showed multifocal heterogeneous masses with cystic lymph nodes. Ultrasound-guided aspiration drained clear fluid (unexamined). The patient persistently refused treatment. Three critical lessons emerge: Stage-independent aggression: N0→N1→N+ progression within 12 months defies salivary adenocarcinoma timelines; Diagnostic failure: Cystic metastases evade cytology; Therapeutic mandate: Early neck irradiation (≥60 Gy) may prevent rapid dissemination. This case mandates: Diagnostic escalation: Core-needle biopsy for all cystic tongue lesions >3 cm; Protocol revision: Prophylactic neck irradiation for CK7+/CDX2− adenocarcinomas regardless of nodal status; Molecular prioritization: NGS profiling (e.g., CLDN18.2/MYB) to identify actionable targets. The paradoxical cystic metastasis phenotype redefines risk stratification in oral oncology.