Benign sacrococcygeal neoplasm arising at birth from a giant congenital melanocytic nevus ☆ Jason A. Snyder, Nini Khozeimeh, Christine Reyes, Faisal G. Qureshi ⁎ Divisions of Pediatric Surgery and Anatomic Pathology, Children's National Medical Center, Washington, DC 20010, USA Received 19 July 2011; revised 2 November 2011; accepted 11 November 2011 Key words: Congenital melanocytic nevus; Congenital giant nevus; Benign neoplasm; Sacrococcygeal neoplasm; Perianal neoplasm Abstract Giant congenital melanocytic nevi (CMN) are considered to be premalignant with the highest risk for conversion to melanoma. Solid tumors within giant CMN presenting at birth are relatively unusual, and a variety of malignancies have been reported within these masses. However, the frequency of malignancy in these tumors is unknown. We report the unusual case of a female neonate who was born with 2 large, perianal masses within a giant CMN over her trunk. We resected the larger of the 2 masses because of discomfort and bleeding. The mass consisted of an outgrowth of melanocytes with benign characteristics. The smaller of the 2 masses was managed expectantly and has subsequently decreased in size. We propose that pathologically benign masses within giant CMNs may not require immediate resection. We will discuss the management and pathologic findings of this case and review the literature regarding management of CMN-associated neoplasms arising at birth. © 2012 Elsevier Inc. All rights reserved. Congenital melanocytic nevi (CMN) are pigmented cutaneous lesions visible at birth resulting from aberrant neural crest cell differentiation and migration [1]. Although smaller lesions are much more common, giant CMN (N20 cm) are rare (1 in 20 000) and are associated with an increased risk of malignant melanoma transformation [2]. No standard exists for long-term management of giant CMNs. Surgical excision is typically performed for large cosmeti- cally disfiguring tumors. Excision of the nevus does not eliminate the melanoma risk. Solid tumors presenting at birth within giant CMNs are relatively unusual. There are several reports on malignancies arising within these solid masses; however, the frequency of solid malignant tumors is unknown [3-7]. We report the surgical approach and pathology of a female neonate who was born with 2 large perianal masses associated with a giant CMN. 1. Case report A 3.2-kg white female infant was born at term after limited prenatal care. The pregnancy was complicated by maternal hypertension, the use of cocaine and marijuana for the first 4 months of gestation, and cigarettes throughout the pregnancy. Examination demonstrated dark-brown pigmented lesion in a swimming-trunk distribution extending circumferen- tially from the umbilicus to the mid thighs consistent with giant CMN (Fig. 1A). Several 2- to 5-mm satellite papules were present on her scalp, extremities, back, and chest. ☆ Disclosure Information: Nothing to disclose. ⁎ Corresponding author. Division of Pediatric Surgery, Children's National Medical Center, Washington, DC 20010, USA. Tel.: +1 202 476 4174(o); fax: +1 202 476 4174. E-mail address: fqureshi@cnmc.org (F.G. Qureshi). www.elsevier.com/locate/jpedsurg 0022-3468/$ – see front matter © 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2011.11.041 Journal of Pediatric Surgery (2012) 47, 408–411