A woman in her 50s presented with a 4-week history of a slowly enlarging mass on the left side of the neck. Physical examination revealed a mobile, nontender, 4-cm mass in the left side of the floor of mouth. A contrast-enhanced computed tomographic scan of the neck showed a 3.8-cm cystic neck mass in the left floor of mouth (Figure, A). An ultrasonography (US)-guided fine-needle aspiration (FNA) biopsy showed bland-appearing cuboidal to columnar epithelial cells arranged in clusters; no malignant cells were identified. Repeated US-guided FNA biopsy showed a hypercellular specimen composed of numerous fragments of bland-appearing cuboidal and columnar epithelium and granular debris, which was eosinophilic in cell block sections and papillary structures with fibrovascular cores. The hypercellularity was atypical, and a low-grade neoplasm could not be ruled out. At this point, the patient elected observation of the mass and a repeated biopsy. A core biopsy showed a well-differentiated papillary neoplasm with hyalinized fibrovascular cores and some degenerative changes (Figure, B-D). Immunophenotypically, the neoplastic cells were negative for the markers TTF-1, PAX-8, estrogen receptor, and thyroglobulin. These results, with the morphologic characteristics, were most consistent with a low-grade salivary neoplasm. She underwent excision of the cystic floor of mouth mass and a level I neck dissection. Pathologic examination revealed a cystic, 2.5-cm encapsulated mass arising from a minor salivary gland.
Harvey R, McHugh J, Ryan J. Floor of Mouth Mass. JAMA Otolaryngol Head Neck Surg. 2016;142(1):91-92. doi:10.1001/jamaoto.2015.2671