Enigma of CD56 and S100 positive-high-grade undifferentiated malignant tumor of uncertain histogenesis of the mandible - A rare case report

Purpose: The purpose of this study was to highlight difficulty index in diagnosing and treating an aggressive and infiltrative malignancy in a young patient. Material: Undifferentiated tumors represent either as a primary neoplastic lesion showing no differentiation or as a metastatic deposit of an unknown primary neoplasm without obvious cell line of differentiation. These tumors are rare and pose a challenge to the diagnosis and treatment outcome. This rare case report is of a young female presenting with an aggressive osteolytic left mandible body pathology. Pre-operative incisional biopsy and post-operative excisional biopsy were subjected to histopathology and immunohistochemical analysis. None of the cellular level diagnostic modalities yielded a definitive diagnosis. The patient was subjected for aggressive resection based on the clinical and imaging findings. Conclusion: From the date of patient presentation to 2 years of follow-up with two surgeries, the concluding histopathology diagnosis was not established. In spite of recent advances in diagnosing, imaging modalities, it is difficult to establish a treatment protocol for disease free survival. It is more agonizing to see a young patient undergoing so much scrutiny with limitations in all advanced medical technology. In such cases wherein definitive diagnosis cannot be achieved despite a thorough cellular level examination, the treatment solely depends on the clinical features of presenting signs and symptoms of the patient.