Tumor or Inflammatory Myofibroblastic Reaction in an Adolescent With an Abdominal Lymphatic Malformation?

We report the case of a 17-year-old male who presented with intractable nausea and vomiting. Cross-sectional imaging revealed a large retrogastric abdominal mass. Fine needle aspiration done via endoscopic ultrasound (EUS) was nondiagnostic. Exploratory laparotomy revealed a large inflammatory mass densely adherent to the stomach and retroperitoneum. Incisional biopsy frozen section revealed spindle cells, and subsequent resection of the mass with en-bloc subtotal gastrectomy with Roux-en-y gastrojejunostomy reconstruction was performed. Final pathology demonstrated a lymphatic malformation with reactive myofibroblastic proliferation. Inflammatory abdominal lymphatic malformations are especially rare and not well described in the literature. These masses may present diagnostic challenges until the specimen is sent for pathologic analysis.