Study of the Histopathologic Characteristics and Surface Morphologies of Glottic Carcinomas With Anterior Vocal Commissure Involvement

Abstract

This article explores the features and the role of the anterior vocal commissure (AVC) structure and the surface morphologies of glottic carcinomas with AVC involvement to provide a reference for the selection of transoral carbon dioxide (CO2) laser surgery. A total of 31 cases of glottic carcinomas with AVC involvement from May 2012 to January 2014 were included. All patients underwent electronic laryngoscopic examinations and computed tomography scans to determine the surface morphology. After surgery, the tumor specimens were resected integrally, and axial serial sections parallel to the plane of vocal cords were taken to explore the features and possible invasion paths of the glottic carcinomas with AVC involvement. The rates of involvement of the supraglottis and subglottis were 71.4% and 14.8%, respectively, via the AVC. The involvement of the superficial layer of the unilateral or bilateral vocal cords without involvement of the vocal muscle in the AVC region (IVM) or the cartilage was present in 15 cases (48.4%). The involvement of the superficial layer of the unilateral and bilateral vocal cords occurred in 16 cases (51.6%) with the IVM in 13 cases and the involvement of the intermediate lamina of the thyroid cartilage (ITC) in 8 cases. The involvement of the ITC was associated with the involvement of the vocal muscle of the AVC region (P < 0.05). Among the pushing carcinomas, 15 of 21 (71.4%) presented with well-defined tumor mass, and 8 of 10 (80.0%) infiltrating carcinomas presented with multiple tumor nests that were often surrounded by fibrosis (P < 0.05). The AVC is an important path of invasion of subglottic in glottic carcinomas but less so for suparglottic. The Broyles' ligaments acted as a barrier against the spread of the tumors to the thyroid cartilage, but this role was obviously weaken by the involvement of the vocal muscle of the AVC region. The infiltrating carcinomas presented with multiple tumor nests in fibrous tissue. When CO2 laser microsurgery is considered as a treatment option, these facts should be kept in mind.

FIGURE 1

Involvement of the vocal cords and Broyles’ ligaments. (A) Involvement of the superficial layers of the bilateral vocal cords in an AVC2 case without involvement of the vocal muscle in the AVC region. (B) Involvement of the superficial layers of the unilateral vocal cords or deep layers of the contralateral in an AVC2 case with involvement of the vocal muscle in the AVC region. (C) The involvement of the deep layers of the bilateral vocal cords in an AVC3 case with involvement of the vocal muscle and the ITC in the AVC region. (D) Magnified image of the areas in the rectangle in (C), ×2.5; laryngeal tumors “ringing” the Broyles’ ligaments and not breaking through to the ventral and dorsal ligaments. H&E, yellow arrows: tumor cells; red arrows: Broyles’ ligament; black arrows: thyroid cartilage. AVC = anterior vocal commissure, H&E = hematoxylin–eosin staining.

FIGURE 2

Involvement of the ITC. (A, B) Amplified image of the rectangle in (A), ×2.5; the ITC outer plate presented with minifocal destruction in a case with unilateral involvement of the LTC. (C, D) Amplified image of the rectangle in (C), ×2.5; the ITCs exhibited bulk destruction of the inner and outer plates with bilateral involvement of the LTC. H&E, yellow arrows: tumor cells; red arrows: Broyles’ ligament; black arrows: thyroid cartilage). H&E = hematoxylin–eosin staining, ITC = intermediate lamina of the thyroid cartilage, LTC = lateral lamina of the thyroid cartilage.

FIGURE 3

Pushing carcinoma. (A) Electronic laryngoscopic, (B) CT, axial, and (C) CT, coronal. A tumor with its main body located in the larynx cavity with a clear tumor edge surface morphology. (D, E) H&E, amplified image of the rectangle in (D), ×2.5. The tumor exhibited well-defined tumor mass. CT = computed tomography, H&E = hematoxylin–eosin staining.

FIGURE 4

Infiltrating carcinoma. (A) Electronic laryngoscopic, (B) CT, axial, and (C) CT, coronal. A tumor with its main body in the vocal propria lamina and the deeper layers and exhibiting an unclear tumor edge surface morphology. (D, E) H&E, amplified image of the rectangle in (D), ×2.5. This tumor exhibited multiple tumor nests that were often surrounded by fibrosis (yellow arrows: tumor cells or tissue). CT = computed tomography, H&E = hematoxylin–eosin staining.