Enteric Duplication Cyst in a 5-year-old Male Child: Masquerading as a Mucinous Neoplasm with a Brief Review of Literature

IntroductIonAlimentary or enteric duplication cysts (EDCs) are uncommon congenital anomalies that occur in approximately 0.2% of all children. 1,2EDCs often present in infancy, though they can occur at any age. 3EDC can manifest anywhere along the gastrointestinal tract, from the mouth to the anus.The most common locations of these duplications are jejunum (52%), followed by the esophagus (17%), colon (14%), stomach (8%), duodenum (6%), and rectum (6%). 4This report discusses a case of a 5-year-old boy with an EDC at the ileocecal junction. case descrIptIonA 5-year-old male patient presented with pain in the right iliac fossa (RIF), 11 months after an appendectomy.Physical examination revealed a mass in the same area, and a contrast-enhanced computed tomography (CT) scan (Figs 1 and 2) showed a thickwalled cystic lesion in RIF.Fine-needle aspiration cytology (FNAC) suggested a mucinous cystic neoplasm.The patient then underwent laparoscopic-assisted open excision of the mass.Specimens were received in four containers labeled as cystic mass, mesenteric lymph node, omental biopsy, and peritoneal biopsy.Gross examination showed a well-circumscribed cystic mass (Figs 3 and4) measuring 3 cm, containing jelly-like, transparent yellow material, with a 0.5-0.7 cm wall thickness.The mesenteric lymph node was a small node measuring 0.7 cm, while the omental and peritoneal biopsies measured 3 cm and 1 cm, respectively.Microscopic examination revealed the cyst wall lined partly by foveolar type (Fig 5) and partly lined by ciliated pseudostratified columnar epithelium (Figs 6 and7) and pyloric-type glands (Fig. 8), with no evidence of dysplasia or malignancy.The histopathological differential diagnosis was teratoma.Immunohistochemistry (IHC) was positive for CK 7 (cytokeratin-7) (diffuse cytoplasmic and membranous) (Fig. 9) and TTF1 (thyroid transcription factor 1) (focal nuclear) (Fig. 10).Other markers such as CK-20, SATB2 (special AT-rich binding protein 2), and PAX8 (paired box gene 8) were negative.The mesenteric lymph node showed reactive changes,