CASE 16700 Published on 15.04.2020

Castleman disease presenting as an indolent mass of the neck

Section

Head & neck imaging

Case Type

Clinical Cases

Authors

João Amorim1,2, Hugo Mota Dória3, Filipa Vilas Boas4, Elisa Melo Abreu2.

1Escola de Medicina, Universidade do Minho
2Radiology Department, Centro Hospitalar Universitário do Porto
3Neuroradiology Department, Centro Hospitalar Universitário do Porto
4Radiology Department, Hospital de Santarém

Contact information: joaopinheiroamorim@gmail.com

Patient

43 years, female

Categories
Area of Interest Head and neck, Mediastinum ; Imaging Technique CT, MR
Clinical History

Female patient, 43 years old, with a slight neck mass on palpation. She had no relevant previous medical history, and no familial history of thyroid cancer. Physical examination was unremarkable besides the already mentioned neck mass.

Imaging Findings

Initial ultrasound examination with fine-needle aspiration was done, with inconclusive results. A neck computed tomography (CT) with and without contrast was performed for characterisation and revealed a well-defined 9 cm soft tissue mass in the right infrahyoid carotid space with extension to the upper mediastinum, displacing the visceral space medially (Fig. 1). The lesion also displaced the internal jugular vein anteriorly and the common carotid vessel posteriorly, encasing this vessel without compressing it. After contrast administration the lesion had mild peripheral enhancement and small, central, hypoenhancing areas. There were no calcifications. Several prominent lymph nodes were identified on the right anterior cervical space, but no other lesions were identified.

On magnetic resonance imaging (MRI), this lesion exhibited spontaneously low T1 and high T2-STIR signal, with mild enhancement after contrast administration (Fig. 2). A PET-CT was performed outside of the authors’ hospital institution, which showed avid FDG uptake associated with the mass.

Discussion

In this report, we describe a case of unicentric Castleman disease that presented as an indolent mass of the neck, pathologically confirmed as hyaline vascular type after surgical excision.

Castleman’s disease was first described in 1956 by Castleman and his colleagues [1]. It is a rare benign condition of the lymph nodes, also known as angiofollicular or benign giant lymph node hyperplasia. The aetiology of this lymphoproliferative disease remains poorly understood, but the current consensus is that there is a wide range of clinical entities within this disease [2].

Unicentric disease is the most common type and it usually presents as an asymptomatic solitary mass, with the most common variant being the microscopic hyaline vascular, which can be surgically treated with success. On the contrary, the multicentric type has a broader histologic range and is usually more aggressive. Of these, the human herpes virus-8 (HHB8)-associated Castleman disease, which occurs in immunosuppressed patients, is the only type in which a specific pathogenic agent is known to cause the disease [2]. The remaining multicentric cases that do not have a specific pathogenic agent are considered in the broad category of idiopathic multicentric Castleman’s disease (HHV8-negative disease) [3]. These cases are rare but life-threatening, and specific diagnostic criteria have been established to facilitate this particularly challenging diagnosis [4].

Even though it is a disease of the lymph nodes which can theoretically affect any nodal chains, unicentric disease has a predilection for the mediastinal nodal chains. Nevertheless, because of its clinical variability and the ability to potentially affect any body region (including the neck, abdomen and pelvis), this disease frequently represents a diagnostic challenge [5].

On imaging studies, unicentric disease usually presents as a well-defined mass that displaces surrounding structures. Because of their high vascularity, these lesions show intense enhancement after contrast administration on both CT or MRI, and intralesional flow voids may be seen on T1- and T2-weighted images [6]. Their location and signal characteristics usually prompt differential diagnosis with neurogenic tumours which are also highly vascular, including paragangliomas and pheochromocytomas, as well as sarcomas or lymphomas. Other rare diagnosis such as ectopic cervical thymoma should also be kept in mind [7]. PET/CT is able to detect increased metabolic activity in the affected lymph nodes, even if their size is normal, and it is a helpful tool for an accurate staging and monitoring of the disease. Nevertheless, excisional biopsy remains the method of choice for diagnostic confirmation [8].

Unlike multicentric disease, this type usually has an excellent outcome after curative surgical treatment, which was the case for our patient.

Take-Home Message: Unicentric Castleman disease is a rare benign disease which should be considered in the differential diagnosis of hypervascular lesions located in the topography of many nodal chains, including the neck. Unlike its multicentric counterpart, unicentric disease is usually associated with the hyaline vascular type and shows an indolent and benign clinical course, with very good outcome after surgical excision, which is needed for the definite diagnosis.

Written informed patient consent for publication has been obtained.

Differential Diagnosis List
Unicentric Castleman disease of the neck and upper mediastinum
Paraganglioma
Jugular schwannoma
Thyroid cancer
Lymphoma
Ectopic cervical thymoma
Metastatic malignant tumour
Final Diagnosis
Unicentric Castleman disease of the neck and upper mediastinum
Case information
URL: https://www.eurorad.org/case/16700
ISSN: 1563-4086
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