{'fraction_non_alphanumeric': 0.02681863895407308, 'fraction_numerical': 0.012738853503184714, 'mean_word_length': 5.178053830227744, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Pediatric nasopharyngeal carcinoma

To the Editor: A 2-year and 8-month-old male with difficulty breathing and neck swelling was referred to our center after a CT showed a nasopyharyngeal mass. MRI of the nasopharynx revealed an 8 cm 7 cm 5 cm mass at the craniovertebral junction, obliterating the nasopharyngeal and oropharyngeal airway with extension to the retroclival space and cervical canal (Fig. 1). Bilateral multiple jugular lymphadenopathy was also seen in MRI. A biopsy of the mass revealed that the tumor consisted of round to oval shaped cells, some of which had hyperchromatic nuclei and formed alveolar structures resembling rhabdomyosarcoma (RMS). Necrotic areas and infiltration of lymphoid cells were noted. Immunohistochemical studies showed expression of keratin AE1– AE3, EMA and vimentin, and negative staining for desmin, muscle specific actin, myogenin and CD99. The histopathological findings were consistent with undifferentiated nasopharyngeal carcinoma (NPC) (Fig. 2A,B). Serum EBV-EBNA IgG and VCA IgG were positive and EBV VCA IgM negative consistent with past infection; EBV-DNA level was not studied at the time. The patient was staged as 4A (T4N2M0) according to American Joint Committee on Cancer NPC staging classification (1997), after a metastatic work-up had been completed [1]. He was started on a chemotherapy protocol, which included cyclophosphamide, vincristine, actinomycin D, and cisplatin. After four courses of chemotherapy, the clinical status had deteriorated and a left hemiparesis developed. The MRI demonstrated an increased extension of the tumor within the canal. Immediate radiotherapy of 51 Gy was given to the nasopharynx and 39 Gy was delivered to the neck. After radiotherapy, the patient’s hemiparesis resolved and the patient was started on a more intensive chemotherapy protocol, because of progression of the disease with initial chemotherapy protocol, which consisted of ifosphamide, carboplatin and etoposide. After initiation of this chemotherapy, respiratory status deteriorated again with marked hypoxia and dyspnea and the patient died, 7 months after the diagnosis due to progressive disease. The mean patient age at presentation of NPC shows a bimodal distribution with an early peak in adolescence [1,2]. In a series from our department, the mean and median ages of the patients with NPC were reported 12.6 and 13 years, respectively, with the youngest patient being 7 years of age [3]. Another case of NPC occurring in a young patient was 3 years and 10 months of age [4]. Since it is one of the most common nasopharyngeal tumors in young children, together with the radiologic and routine histopathologic findings, RMS was thought to be the initial diagnosis. Although nasopharyngeal carcinoma is known to be a highly responsive to chemotherapy, the initial chemotherapy response in our patient was poor. The young age of our patient may be responsible from this atypical clinical progress despite treatment.