Primary congenital sacrococcygeal neuroblastoma: A case report with immunohistochemical study and review of literature
A 9-month-old baby girl brought to pediatric surgery outpatient department, presented with swelling in the sacral region since birth. The swelling was initially small and later increased to present size. Local examination showed round and globular swelling measuring 6 × 5 cm. Overlying skin was unremarkable. Systemic examination findings were noncontributory. The female child was born full term by uneventful normal vaginal delivery. She achieved normal milestones for age and was immunized appropriately for age. Laboratory investigations such as liver function tests, renal function tests, plasma glucose levels, and chest X-ray were normal.\nMagnetic resonance imaging findings of the sacrococcygeal mass: T2W sagittal images showed a well-defined lobulated lesion in the pre and retro sacrococcygeal region, encasing the coccyx. The lesion was isointense to hyperintense in signal intensity and showed fine internal septations within []. On the basis of clinical and radiological findings, a provisional diagnosis of solid variant of sacrococcygeal teratoma (SCT) was made.\nCaudal and general anesthesia was given and the swelling was entirely excised with the part of the coccyx. Postoperative course was uneventful.\nOn gross examination, the tumor was well-circumscribed having smooth and lobulated external surface, firm in consistency, and measured 6 × 6× 5 cm. On cut section, the tumor appeared nodular, greyish white with focal hemorrhagic areas in the periphery [].\nOn microscopic examination, a well-circumscribed tumor composed of round to oval cells with prominent nucleoli and scanty to moderate cytoplasm. The cells were seen arranged predominantly in nests. Also seen were few sheets and lobules, separated by thick and thin fibrovascular septae. Many areas showed presence of Homer Wright pseudorosettes []. At few places, the tumor showed neuropil and schwannian stroma. Amid this, were noted large cells differentiating into ganglion cells [ inset]. There was paucity of abnormal mitotic figures and karyorrhectic activity. On the basis of these findings, diagnosis of neuroblastoma in the sacrococcygeal region was considered and representative sections were subjected to immunohistochemical studies.\nImmunohistochemistry (IHC) was performed with the following panel of antibodies utilized for differential diagnosis of small round cell childhood tumors which included neuroendocrine markers like neuronspecific enolase (NSE) (Dako) chromogranin-A (clone 5H7, Leica) and synaptophysin (clone 27G12, Leica). Other markers included were S-100 (Leica), CD99 (clone 12E7, Dako), leucocyte common antigen (LCA) (clone, 2B11 + PD 7126), pancytokeratin (PanCK) (clone AE1/AE3, Dako), epidermal growth factor receptor (EGFR) (clone EGFR.25, Leica), cyclin D1 (clone P2D11F11, Leica), P53 (cloneDO-7, dako) and Ki-67 (clone MIB-1, Dako). Strong cytoplasmic immunoreactivity was observed with NSE [], synaptophysin and it was patchy with chromogranin []. S-100 showed positive cytoplasmic immunoreactivity. CD99 [], LCA, PanCK, and EGFR were nonreactive. Cyclin D1 showed strong nuclear immunoreactivity []. P53 was negative and Ki67 labelling index was less than 1%.\nThe above histomorphological studies confirmed the diagnosis of low grade primary sacrococcygeal neuroblastoma (SCN).