Malignant carotid body tumor: a report of two cases

Carotid body tumors (CBT) are neoplasms that originate from chemoreceptors of the carotid body. They are neuroendocrine tumors that are usually benign but may have malignant potential. Malignancy is diagnosed with evidence of lymph node metastasis, distant metastasis, or disease recurrence. Multiple imaging modalities are used to diagnose CBTs and the treatment of choice is surgical excision. Radiotherapy is used for unresectable tumors. In this case, series we describe two cases of malignant paragangliomas that were diagnosed and operated on at a tertiary hospital in Kuwait, by the vascular team. Malignant CBTs are rare, documentation of the cases encountered and the subsequent management and outcome is important to give us a better understanding of the disease.

Case one- A 23-year-old woman presented with a right-sided neck mass. History, physical examination, and appropriate imaging suggested malignant paraganglioma with evidence of lymph node, vertebral, and lung metastases. Surgical excision of the tumor and regional lymph nodes was done. Histopathological assessment of the retrieved specimens confirmed the diagnosis. Case two - A 29-year-old woman presented with a left submandibular swelling. She was appropriately investigated, and the diagnosis of a malignant carotid body tumor was made with evidence of lymph node metastasis. Surgical resection of the tumor with clear margins was done and histopathological analysis of the resected specimen confirmed the diagnosis.

CBT's are the most common tumors of the head and neck. Most are nonfunctioning, slow growing, and benign. They typically present in the fifth decade of life but can occur at a younger age in individuals who carry certain genetic mutations. Both cases of malignant CBT's that we encountered occurred in young women. Furthermore, the 4-year and 7-year history in case number one and two, respectively, supports the fact that CBTs are slow growing tumors. In our case series, the tumors were surgically resected. Both cases were discussed in multidisciplinary meetings and were referred for hereditary testing and radiation oncology for further management.

Malignant carotid body tumors are rare. Prompt diagnosis and treatment is important to improve patient outcomes.