Collision tumors in children: a review of the literature and presentation of a rare case of mesoblastic nephroma and neuroblastoma in an infant

Primary Central Nervous System Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type Colliding with Meningioma

BACKGROUND

Collision tumors are defined as coexistence of 2 histologically different neoplasms occurring in the same anatomic location. Such co-occurrence of tumors in the brain is uncommon. To our knowledge, meningioma colliding with extranodal natural killer/T-cell lymphoma has not been described previously.

CASE DESCRIPTION

A 50-year-old man presented with a 1-year history of progressive memory decline and 2 weeks of drowsiness, bradykinesia, and aphasia. Magnetic resonance imaging revealed a heterogeneously enhanced mass beside the left frontal cerebral falx resulting in midline shift. The left frontal lobe mass was resected. Pathologic examination showed the tumor consisted of whorled spindle cells and diffuse medium-sized lymphoid cells. The spindle cells were positive for epithelial membrane antigen and negative for S-100. The lymphoid cells expressed CD3ε, CD56, TIA-1, and granzyme B. Epstein-Barr virus encoded small RNAs were detected by in situ hybridization. No monoclonal T-cell receptor gamma gene rearrangement was detected. Four weeks after surgery, the patient was treated with polychemotherapy and intrathecal methotrexate, but he died 2 months later.

CONCLUSIONS

This is the first report of a unique brain collision tumor consisting of a meningioma and an extranodal natural killer/T-cell lymphoma. Diagnosis depends on histopathology. Awareness of this entity is important to distinguish it from other intracranial tumors.

Coexisting differentiated neuroblastoma and ossifying renal tumor of infancy in a patient

We presented a 5-month-old boy with differentiated neuroblastoma and ossifying renal tumor of infancy (ORTI) arising at the left adrenal gland and upper pole of the ipsilateral kidney, respectively. They were located in the adjacent organs with different morphology and immunohistochemistry characteristics. To our best knowledge, coexistence of differentiated neuroblastoma and ORTI in a patient has never been reported. In our report, two contiguous lesions might be represented collision tumor, originated from the same clusters of immature cells and triggered by different mechanism.

Synchronous occurrence of metastatic Wilms tumor and ganglioneuroma

We describe a 4-year-old female patient with a persistent paraspinal mass following chemotherapy for Wilms tumor. A discordant response to chemotherapy prompted biopsy of the persistent mass, which revealed a ganglioneuroma. This report highlights the synchronous occurrence of different tumors in the same patient, and suggests that repeat biopsies should be considered when contiguous tumor masses do not respond as expected.

Multiple synchronous tumors in a child with Fanconi anemia

Fanconi anemia (FA) is an autosomal recessive inherited syndrome characterized by congenital abnormalities, aplastic anemia, and a high likelihood of developing cancer. We describe a child who presented with 2 synchronous solid tumors (Wilms tumor and neuroblastoma), later found to have FA, who developed severe toxicity and died after a first cycle of chemotherapy. Our experience emphasizes that a predisposing genetic condition should be sought in cases of multiple tumors and that managing FA patients with cancer can be particularly difficult.