Paragangliomas Arising From the Laryngeal Paraganglia: Thyroid and Laryngeal Paragangliomas With Radiology-Pathology Correlation

Abstract

Paragangliomas are neuroendocrine tumors that arise from the embryonic neural crest cells of the extra-adrenal chromaffin and non-chromaffin cellular system. Paragangliomas arising from the laryngeal paraganglia, which occur in the thyroid and larynx, are a rare subset of paragangliomas compared to the more common locations of the carotid body, vagale, jugular, and tympanic paragangliomas. The preoperative diagnosis of both thyroid and laryngeal paragangliomas may pose a challenge due to cytological, pathological, and imaging non-specificity that overlaps with many other neoplasms. These lesions may be associated with significant intraoperative bleeding and complicated excision with adherence to nearby structures, including the recurrent laryngeal nerve. This article discusses the imaging appearance, pathological features, clinical and operative considerations and manifestations, and management of head and neck paragangliomas, as seen in two patients at our institution.

Keywords: head and neck paraganglioma (hnpgl); laryngeal paraganglioma; nonfunctional paraganglioma; supraglottic paraganglioma; thyroid paraganglioma.

Figure 1. Thyroid ultrasound.

Initial thyroid color Doppler (A) and grayscale (B) ultrasound images demonstrate a heterogeneous thyroid gland with an enlarged and hypervascular right thyroid lobe/isthmus (arrowheads, B).

Figure 2. CT of the soft tissue neck with intravenous contrast axial (A, D) and coronal (B, C) views.

The most recent CT of the soft tissue neck with intravenous contrast demonstrates an enlarged heterogeneously enhancing thyroid with an exophytic right thyroid lobe nodule (solid arrowheads) extending into the isthmus. The nodule is supplied by enlarged and tortuous inferior (solid arrows) and superior (hollow arrows) thyroidal arteries. Extensive arterial and venous collaterals are noted (hollow arrowheads). The normal right inferior thyroid artery is denoted by a solid triangle for comparison.

Figure 3. External carotid arteriogram.

Early arterial (A) and late arterial (B) phases demonstrate extensive enhancement in the region of the right thyroid paraganglioma (arrowheads) supplied by a prominent superior thyroidal artery with multiple smaller collaterals (arrows).

Figure 4. Thyroid paraganglioma microscopic evaluation.

(A) Hematoxylin and eosin staining (200×). Monomorphic tumor cells arranged in a well-defined nest (zellballen) pattern surrounded by a thin fibrovascular stroma (arrowheads on a few characteristic nests). (B) S100 immunostain (200×) highlights sustentacular cells along the periphery of the cellular nests (arrows). (C) Immunostain for synaptophysin is positive in the cytoplasm of the tumor (brown pigment).

Figure 5. CT of the soft tissue neck with intravenous contrast.

Initial axial CT of the soft tissue neck with intravenous contrast (A) demonstrates an enhancing well-circumscribed 4.7 cm mass (arrowheads) centered in the left supraglottic larynx with significant mass effect and no extralaryngeal extension. Extensive surrounding vascularity (arrows) is noted on both the CT and time-of-flight magnetic resonance angiography (B).

Figure 6. Catheter angiogram of the neck.

Catheter angiogram with common carotid artery injection (A) and external carotid artery injection (B) demonstrate tumor blush of the supraglottic paraganglioma (solid arrowheads), supplied by the inferior thyroidal artery (hollow arrow) and superior thyroidal artery (solid arrow). The thyrocervical trunk is denoted by the hollow arrowhead.

Figure 7. Microscopic evaluation of supraglottic paraganglioma.

(A) Hematoxylin and eosin stain (200× magnification) shows clusters of cells (arrowhead on a few characteristic clusters) surrounded by thin vascular channels (zellballen pattern). (B) Chromogranin immunostain (200× magnification) is positive in the cytoplasm of tumor cells (brown pigment).