Available online 5 December 2022, 152071

Three cases of primary neuroblastomas presenting as anterior mediastinal tumors are presented. The patients are two women and one man between the ages of 57 and 63 year. Clinically, the patients presented with symptoms of chest pain, cough, and shortness of breath. Diagnostic imaging revealed the presence of an anterior mediastina mass. Initial biopsy was non-diagnostic in two patients, while in one patient no biopsy was obtained. Surgical resection via thoracotomy was performed in all three patients. Grossly, the tumors vary in size from 3 to 4.5 cm in greatest dimension, and they were described as well circumscribed but not encapsulated, light brown in color. Areas of hemorrhage and/or necrosis were not described. Histologically, at low power the tumors were surrounded by a rim of adipose tissue containing remnants of thymic tissue with Hassall's corpuscles. At higher magnification, the tumors show the characteristic small round cell proliferation with varying amounts of neurophil. Mitotic activity was present but not in large number. Areas of necrosis and/or hemorrhage were not identified. Immunohistochemically, the tumors show positive staining for NSE, while synaptophysin highlighted neurophil. Other markers epithelial and neuroendocrine were negative. Clinical follow-up information shows that two patients have remained alive 8 and 12 months after initial surgical resection. One patient was lost to follow-up.

Neuroblastomas and ganglioneuroblastomas are tumors predominantly of the pediatric age group. Anatomically, these tumors occur more often in the abdomen and adrenal gland with small proportion of cases in the thorax and the head and neck area [1]. Regarding the occurrence of these tumors in the thoracic area, the posterior mediastinum is the more common location, and the vast majority of neuroblastoma and ganglioneuroblastomas occur in children under the age of 5 years [2]. Because of this location within the thoracic cavity, some of these children may present with symptoms of paraplegia, neurogenic bladder, or Horner's syndrome, depending on the location of the mass [1]. Regarding the occurrence of neuroblastomas in the pediatric age group, it has been estimated that these tumors represent about 10 % of all malignancies and 15 % of deaths in this group [3], while on the other hand, it has been estimated that the occurrence in the thorax is of approximately 20 % [1].

On the other hand, the occurrence of neuroblastomas in adults although rare, it has been also reported in the literature. The occurrence of these tumors seems to follow similar anatomical distribution as the ones in the pediatric group. Therefore, within the thorax, the posterior mediastinum is the most common location. However, in the cases herein described not only the tumors show the conventional features of neuroblastoma but also the location is in the anterior mediastinum.

Three cases of anterior mediastinal neuroblastomas form the basis of this report. All available clinical information was obtained from the respective physicians and all diagnostic imaging information was also available for review. Microscopic hematoxylin-eosin histological sections were available for review ranging from 5 to 7 sections per case. In addition, unstained sections were available for immunohistochemical stains including pan-keratin (Dako; 1:100), NSE (Dako; 1:), S-100 protein

The patients are two women and one man between the ages of 57 and 63 years. None of the patients had prior history of malignancy, and consulted because of chest pain, cough, and shortness of breath. Diagnostic imaging revealed the presence of anterior mediastinal mass (Fig. 1A, B). All patients undergo surgical resection of the anterior mediastinal tumor via thoracotomy.

Macroscopically, the tumors were described as well circumscribed tumors surrounded by adipose tissue and measuring from 3 to

Primary neural tumors in the mediastinal compartment are well known to occur, essentially in the posterior mediastinum. Although neuroblastomas and ganglioneuroblastomas are more common in the pediatric age group, in the adult population the more common tumors are neurofibromas of ganglioneuromas. However, it is also important to highlight that unusual tumors such as ependymomas have also been described [4]. Also, unusual cases of schwannomas have been described in the anterior mediastinum [5].

The authors do not have any conflict of interest regarding the elaboration of this manuscript. In addition, no specific funding was provided in the preparation of this manuscript.

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