P2.M241: Non-Hodgkin Lymphoma Presenting as Abdominal Pain in an Adolescent Female

Introduction: Non-Hodgkin lymphoma (NHL) is a common malignancy in the pediatric population, even more so in adolescents (1). Those with high grade NHL typically present with “B symptoms” including fever, weight loss, night sweats, lymphadenopathy, weakness, or decreased appetite (2). Without these symptoms, it can be difficult to clinically diagnose a lymphoma prior to it reaching a higher stage.

Case Description: A 16-year-old female with no significant past medical history presented to her primary care pediatrician with generalized abdominal pain of 3 weeks duration. The pain was described as intermittent but progressive, reaching 8/10 severity and impairing ambulation. She denied gastrointestinal symptoms, menstruation changes, and “B symptoms”, and was sent to the Emergency Department for further evaluation. ED physical exam was significant for diffuse abdominal tenderness and distension, no lymphadenopathy or hepatosplenomegaly were appreciated. An abdominal ultrasound showed bilateral lobular masses, and Magnetic Resonance Imaging demonstrated multiple abdominal masses with marked internal heterogeneity.
There was high suspicion for a germ cell tumor etiology due elevated LDH and CA-125, with normal CA 19-9, CEA, AFP, and inhibins. The Gynecologic Oncology team was consulted for the surgical resection, which revealed a lack of normal ovarian parenchyma, and resulted in a right salpingo-oophorectomy and appendectomy. The cancer was classified as Stage III due to it being “extensive primary intra-abdominal disease, unresectable”, with additional appendiceal and mesentery nodules. The left ovary and some tumor tissue were spared to preserve fertility.
Pathology revealed a differential of high-grade B cell NHL and Burkitt-like lymphoma with 11q aberration, and with no bone marrow nor cerebrospinal fluid infiltration. The patient has completed the ANHL 1131 Group B protocol Pre-Phase COP (Cyclophosphamide, Oncovin/vincristine, and Prednisone) and one block of Induction with COPADM-R (Cyclophosphamide, Oncovin/vincristine, Prednisone, Adriamycin/Doxorubicin, Methotrexate, Rituximab). She has shown an incomplete metabolic response to these, which is the desired response after Pre-Phase. The next stage of treatment is the second block of Induction and two blocks of Consolidation R-CYM (Rituximab, Cytarabine, and Methotrexate), followed by another PET/CT.

Discussion: Abdominal pain is a nonspecific symptom that can implicate several differential diagnoses including ovarian torsion, ectopic pregnancy, appendicitis, or bowel-related pathologies (3). Although abdominal presentation of primary B cell NHL is documented in the literature, this case demonstrates how NHL can mimic a germ cell tumor presentation. The nature of the case also highlights the coordination of primary pediatric care with oncologic and gynecologic care as a key to managing abdominal malignancies and promoting discussion of fertility implications.

Conclusion: To our knowledge, this is a rare report of a pediatric case of B cell NHL presenting with primary abdominal tumor with ovarian involvement. Prognosis for NHL is approximately 90% 5-year survival for individuals under the age of 20, with little recurrence (4).