Peripheral neuroblastoma in an adult: Rare disease at a rare site

Adult peripheral neuroblastoma represents less than 1% of all malignant primary tumors of peripheral nerves. We report a young adult who presented with swelling over the left wrist with left epitrochlear and axillary lymph nodes. Incision biopsy of the swelling was suggestive of malignant small round cell tumor. On immunohistochemistry, cells were positive for synaptophysin, chromogranin and nonspecific enolase and negative for leucocyte common antigen, cytokeratin, CD99 and myogenin. Urinary vanillyl mandelic acid and homovanillic acid levels were elevated. The patient received 8 cycles of chemotherapy (OJEC). Reassessment positron emission tomography-computed tomography scan showed a complete metabolic response at the primary site and partial response at left axillary lymph nodes. The patient underwent axillary lymph node clearance followed by radiotherapy to the tumor bed and lymph node regions. The patient could not afford autologous haematopoetic stem cell transplant and was started on isotretinoin maintenance. He is on follow-up for 12 months and disease free.