Background: Diagnosis of two pathologies, including a neoplasm and infectious condition, by fine needle aspiration (FNA) cytology in the same patient is rare.
Case: A 2-year-old, male child presented with fever, abdominal pain and abdominal mass. Imaging findings were strongly in favor of a neuroblastoma. FNA smears from the mass revealed fecal material containing numerous trophozoites of Giardia lamblia. FNA was repeated in view of the imaging findings. Repeat smears showed a small round cell tumor with rosettes and background filamentous/fibrillar material consistent with a neuroblastoma. Chemotherapy reduced the mass considerably. Histopathology of the resected residual mass revealed a ganglioneuroma in addition to remnants of neuroblastoma. The patient was free of disease two years after the initiation of chemotherapy.
Conclusion: When FNA cytology shows an infectious pathology in the clinical and imaging setting of a tumor, FNA should be repeated so that an important component of the diagnosis is not missed.