Solitary Extramedullary Plasmacytoma of the Larynx and Secondary Laryngeal Involvement in Plasma Cell Myeloma: Single-Centre Retrospective Analysis and Systematic Literature Review

Abstract

The involvement of the larynx in plasma cell myeloma (PCM) may manifest as solitary extramedullary plasmacytoma of the larynx (sEMP-L) or as infiltration of the larynx during newly diagnosed or relapsed systemic disease with bone marrow involvement (plasma cell myeloma with laryngeal involvement, PCM-L). To increase knowledge about these rare conditions, we performed a retrospective analysis along with a comprehensive literature review of cases of sEMP-L or PCM-L. Six patients (two sEMP-L and four PCM-L) were identified in our tertiary laryngological centre from 2009 to 2021, constituting 0.88% of all malignant laryngeal tumours. The literature search yielded 187 cases, including 152 sEMP-L and 35 sPCM-L. A comparison of baseline characteristics between sEMP-L and PCM-L performed in the combined cohort of cases from literature review and retrospective analysis revealed that patients with sEMP-L were younger (56 vs. 64 years, p ≤ 0.001) and presented less commonly with thyroid or cricoid cartilage involvement (2.2% vs. 30.8%, p ≤ 0.001). The prognosis of sEMP-L was better than PCM-L (overall survival 86% vs. 55% at 5 years, p = 0.002). Analysis of potential factors that could influence progression-free survival (PFS) in the group of sEMP-L revealed that male sex and cartilage involvement negatively affected PFS in univariate analyses, while only cartilage involvement retained statistical significance in multivariate analysis (HR = 19.94, p = 0.024). In conclusion, PCM with laryngeal involvement is sporadic. Secondary involvement of the larynx during PCM might be more common than sEMP-L and is associated with worse survival. The involvement of cartilage adversely influences the outcome of sEMP-L.

Keywords: extramedullary plasmacytoma; larynx; multiple myeloma; plasma cell myeloma.

Figure 1

Endoscopic view of hypertrophic right ventricular fold (red arrow) of patient’s larynx infiltrated with extramedullary plasmacytoma (A). Neck CT scan of large tumour mass involving laryngeal structures on the right side with thyroid cartilage destruction and extralaryngeal infiltration of infrahyoid muscles (blue arrow) with increased tissue enhancement (B) and progressing to the subglottic level bilaterally with anterior part of cricoid cartilage destruction (yellow arrow) (C). Histological view of hematoxylin and eosin staining of core biopsy laryngeal specimen with mature plasma cells x10 (D). Immunohistochemical positivity for CD138 antigen x10 (E) with weak cytoplasmic kappa light chain positivity x10 (F) and complete absence of lambda light chain expresssion x10 (G).

Figure 2

Endoscopic view of bulky extramedullary plasmacytoma invading right side of the larynx and hypopharynx (yellow asterisk) (A). Neck CT scan of large tumour mass involving laryngeal structures at the glottic and supraglottic level, with extralaryngeal spread and thyroid cartilage sclerotization and partial destruction (red arrow) without increased tissue enhancement (B). The infiltration involves also both thyroid gland lobes with moderate narrowing of the trachea (red arrow) (C). Histological view of hematoxylin and eosin staining of laryngeal specimen with plasma cells infiltrating muscles x10 (D) x40 (E) and strong cytoplasmic kappa light chain positivity x10 (F) with complete absence of lambda light chain expression x10 (G) and immunohistochemical positivity for CD138 antigen x10 (H).

Figure 3

Graphical representation of the process of selecting articles for literature review regarding laryngeal involvement in plasma cell myeloma. sEMPL—solitary extramedullary 4myeloma with involvement of the bone marrow and secondary involvement of the larynx. PCM-L—secondary laryngeal involvement in plasma cell myeloma.

Figure 4

Comparison of overall survival by Kaplan–Meier method between patients with solitary extramedullary plasmacytoma of the larynx (sEMPL) and patients with plasma cell myeloma with involvement of the bone marrow and extramedullary infiltration of the larynx (PCM-L) in the combined cohort of patients from the literature review (n = 173) and retrospective analysis (n = 6). P derived from log-rank test.

Figure 5

Comparison of progression-free survival by Kaplan–Meier method between male and female patients with solitary extramedullary plasmacytoma of the larynx in the combined cohort of patients from the literature review and retrospective analysis. P derived from log-rank test.