C0391 - THE CASE OF A NEWBORN INFANT WITH A COMPLETE SPONTANEOUS REGRESSION OF A GIANT PARAVERTEBRAL MALIGNANT MESENCHYMAL TUMOR FOLLOWING OPEN BIOPSY. CASE REPORT AND REVIEW OF THE PUBLISHED LITERATURE
1Hospital Marqués de Valdecilla, Santander, Spain. 2Neurosurgery Department; 3Department of Pathology; 4Department of Neuroradiology, Sant Joan de Déu Hospital, Barcelona, Spain.
Objectives: To present the case of a female newborn infant with normal prenatal echographic controls during the early stages of pregnancy with the exception of the last echography that revealed a dorso-lumbar mass, thus a fetal MRI was requested that showed a left paravertebral mass with no apparent medullar involvement. She was brought to our emergency room immediately after birth at another hospital with a 6 × 5 cm left paravertebral mass. Throughout admission, the patient showed no signs of neurological involvement on physical examination. After neuroimaging studies revealed no definitive diagnosis, she underwent an elective open biopsy that revealed a mesenchymal tumor with a hemangiopericytoma like cellular pattern with highly positive surface cell malignant antigen markers. No cytolytic nor cytostatic treatment of any kind was administered. On follow-up imaging controls, the mass spontaneously decreased its size significantly, until complete regression was documented.
Methods: We conducted an on-line search in PubMed that included the key words “malignant”, “mesenchymal”, “tumor”, and “newborn” that yield a total of 91 results.
Results: The vast majority corresponded with GI tract tumors, hematologic and respiratory cases, only one with a sacral chondrosarcoma and none corresponded with a complete giant malignant mesenchymal hemangiopericytoma like tumor.
Conclusions: The presentation of this case was highly atypical. Adequate prenatal screening guidelines allowed a prompt diagnosis. It is known that clusters of mesenchymal cells may spontaneously regress in patients, nevertheless the reported case constitutes the first spontaneous complete resolution of a giant malignant mesenchymal tumor.