"Anemone" cell (villiform) tumor of the brain

Anaplastic ependymoma metastases though a ventriculoperitoneal shunt

Ependymomas are rare glial tumors that comprise 10% of intracranial pediatric malignancies. Primary central nervous system malignancies can rarely metastasize extracranially. When metastases occur, it usually does so in the setting of surgical manipulation of the central nervous system and can spread through the blood, lymph, or artificial means, for example, a ventriculoperitoneal shunt. We describe the presentation and progression of an 18-month-old boy diagnosed with an ependymoma. Initially managed with surgery, radiation, and ventriculoperitoneal shunt placement for symptomatic hydrocephalus, the tumor later recurred with drop metastasis to the thoracic spinal cord. The patient subsequently developed extensive metastases within the abdominal cavity, which were seeded through a ventriculoperitoneal shunt. We present a case of a rare complication of intra-abdominal tumor seeding and carcinomatosis from an intracranial ependymoma through a ventriculoperitoneal shunt. This is a rare presentation of a possible complication, which requires awareness of both surgeons and radiologists.

Diagnosis of an anemone cell tumor as a B-cell lymphoma by molecular analysis

An 83-year-old man presented with mediastinal and axillary lymphadenopathy. Immunophenotyping and electron microscopy performed on an excision biopsy were inconclusive. On a repeat biopsy a year later the ultrastructural features typical of an anemone cell tumor were seen. A panel of monoclonal antibodies showed positivity for vimentin only. The diagnosis of a high-grade B-cell lymphoma could be made only after detection of immunoglobulin gene rearrangement by polymerase chain reaction gene amplification.

Anaplastic large cell Ki-1 lymphoma of the stomach with villopodial projections: an immunocytochemical and ultrastructural study and review of the literature

The report describes a case of anaplastic large cell Ki-1 lymphoma of the stomach with a rapidly fatal course observed in a 28-year-old woman. By electron microscopy the neoplastic cells presented long projections of the cytoplasmic membrane arranged uniformly along all the cell circumference. The morphology and distribution of these projections were characteristic, and the term villopodial is proposed for them. A review of the literature revealed 18 cases of lymphoma and 7 cases of nonlymphoid neoplasms composed of cells with projections similar to those observed in the present case. It is suggested that such tumors be denominated villopodial lymphomas and villopodial tumors. The present case is the first anaplastic large cell Ki-1 lymphoma with villopodial projections reported in the literature.