Primary paratesticular neuroblastoma in a newborn – case presentation and literature review

Abstract

Neuroblastoma is the most common malignancy in infants (25–50 cases per million). A previously healthy 3-week-old Caucasian male newborn presented with a right scrotal mass. The child was born at 39 weeks of gestational age after an uneventful pregnancy. Scrotal ultrasound revealed a 20 mm (length) × 15 mm (width) heterogeneous mass, which was localized on the superior pole of the right testicle with increased vascularity. The mass had no calcifications or necrotic areas. Preoperative tumor markers, β-human chorionic gonadotropin, and α-fetoprotein were normal. During surgery, a well-circumscribed, soft, reddish mass measuring 25 mm in length, 25 mm in width, and 15 mm in depth was found at the level of the spermatic cord and was excised without orchiectomy (Fig. 1). Histological examination revealed a neuroblastoma, positive for synaptophysin CD57 and Ki67. The pathological diagnosis was poorly differentiated neuroblastoma, with poor Schwannian stroma. Computed tomography of the thorax, abdomen, and pelvis was unremarkable. Amplification of N-myc oncogene was absent. The following markers were obtained after the histopathological report: vanillylmandelic acid (VMA) and homovanillic acid (HVA) were normal. Neuron specific enolase (NSE) was 24.73 ng/mL (normal values < 16.3 ng/mL). The case was classified as Stage I according to the International Neuroblastoma Staging System. Considering the patient's age, poor Schwannian stroma, low mitosis-karyorrhexis index, and absence of N-myc gene amplification, the case was classified as having favorable histology. Six months after surgery, bone marrow biopsy was performed without evidence of additional disease; VMA and HVA were within normal values, and NSE had decreased to 20.22 ng/mL. Abdominal and scrotal sonography did not reveal any residual tumor. The patient did not receive adjuvant chemotherapy and was in good health without any sign of recurrence at the 24-month follow-up. The clinical differential diagnosis of paratesticular neuroblastoma should include patent processus vaginalis, inguinal hernia, and hydrocele or a spermatic cord cyst. Through histological frozen section, the differential diagnosis should be made with small blue round cell tumors, such as rhabdomyosarcoma. Since 1980, 11 cases of paratesticular neuroblastoma have been described in the literature1Hua X. Mao-Sheng X. Hong-Quan G. Fang C. Primary paratesticular neuroblastoma: a case report and review of literature.J Pediatr Surg. 2008; 43: e5-e7Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar, 2Berger M. Hurtado M.F. Bertolez S.P. Fernandez-Pineda I. Primary paratesticular neuroblastoma: an important differential diagnosis.J Pediatr Urol. 2012; 9: e117-e122Abstract Full Text Full Text PDF Scopus (2) Google Scholar, 3Strine A. Rescorla F. Misseri R. Primary paratesticular neuroblastoma: report of 2 cases and review of the literature.J Pediatr Surg Case Rep. 2014; 2: 184-186https://doi.org/10.1016/j.epsc.2014.03.011Crossref Scopus (1) Google Scholar (Supplementary Table 1). Paratesticular tumors are usually benign; in cases of malignant lesions, rhabdomyosarcoma is usually diagnosed. The frozen section examination of paratesticular neuroblastoma highlights a small blue round cell tumor, the same as in rhabdomyosarcoma cases. Even immunohistochemistry examination cannot easily differentiate between the two entities if specific markers are not used. Examining the published cases, we found that frozen section examination usually revealed a small blue round cell tumor that was suspected to be rhabdomyosarcoma,1Hua X. Mao-Sheng X. Hong-Quan G. Fang C. Primary paratesticular neuroblastoma: a case report and review of literature.J Pediatr Surg. 2008; 43: e5-e7Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar, 2Berger M. Hurtado M.F. Bertolez S.P. Fernandez-Pineda I. Primary paratesticular neuroblastoma: an important differential diagnosis.J Pediatr Urol. 2012; 9: e117-e122Abstract Full Text Full Text PDF Scopus (2) Google Scholar, 3Strine A. Rescorla F. Misseri R. Primary paratesticular neuroblastoma: report of 2 cases and review of the literature.J Pediatr Surg Case Rep. 2014; 2: 184-186https://doi.org/10.1016/j.epsc.2014.03.011Crossref Scopus (1) Google Scholar and because of that orchiectomy was decided in five out of seven cases (71%). A simple excision of the tumor without orchiectomy was performed in five patients (45%) having no recurrence of the disease at a follow-up of 6 months–10 years. None of the tested tumors presented amplification of the N-myc gene. Prognosis, as considered by the authors, was deemed favorable in all cases if no recurrence of disease was present at the last follow-up. In conclusion, we presented a second case of neonatal paratesticular neuroblastoma reported in the literature. Radical orchiectomy or adjuvant chemotherapy is unnecessary in the case of primary paratesticular neuroblastoma. Excision of the tumor showed no difference from radical orchiectomy in terms of disease recurrence. The authors have no conflicts of interest relevant to this article. The following is the Supplementary data to this article: Download .docx (.02 MB) Help with docx files Multimedia component 1