Vocal Cord Paralysis and Parathyroid Cyst
Aim: Parathyroid gland lesions are extremely rare clinical entity, mostly manifesting as adenoma and hyperplasia, rarely as parathyroid cyst and most infrequently as carcinoma. Parathyroid cysts (PTCs) are frequently asymptomatic lesions of the neck and superior mediastinum with only 300 cases reported in the literature. Symptomatic PTCs are very rare. Vocal cord paralysis (VCP) due to recurrent laryngeal nerve (RLN) dysfunction may herald the presence of neck and mediastinal disease including a variety of neoplastic, inflammatory and vascular conditions. The aim of this report is to describe their clinical presentation, diagnostic procedures, and therapeutic approaches. The objective of the study was to assess the presence of VCP and RLN dysfunction, as well as their association with PTCs.
Patients and methods: We performed 12-year departmental review of parathyroid lesions and PTCs. Retrospective analysis of clinical data on 20 630 unselected patient submitted to thyroid gland and neck ultrasonography yielded 149 (0,007%) patients with parathyroid lesions, six (0,0003%) of them with parathyroid cysts. A comprehensive review of the literature revealed 18 patients with VCP and PTCs.
Results: Parathyroid adenoma were present in 97 (0,65%) and hyperplasia in 46 (0,30%) patients with parathyroid lesions. PTCs were present only in six of 149 (0,04%) patients with parathyroid lesions. Five patients had asymptomatic nonfunctional PTCs, with VCP diagnosed in one female patient. In the 19 patients with PTCs and VCP reported in the literature (including the patient reported here), nine and ten patients had PTCs localized in the neck and mediastinum, respectively. Mediastinal cysts were twofold greater than those localized on the neck, while left RLN dysfunction was recorded in 80% of cases. Cyst removal resulted in RLN functional recovery in two-thirds of patients.
Conclusion: Parathyroid cysts are rare, mostly asymptomatic pathologic lesions of parathyroid glands, which should be taken in consideration in patients with hyperparathyroidism or vocal cord paresis.
Key words: parathyroid lesion; cyst; vocal cord; paralysis; cytology