Recurrent Phosphoglyceride Crystal Deposition Disease in the Mandible Mimicked a Malignant Tumor: Insights from a Clinical Case Report and Literature Review

<b>Background and Clinical Significance</b>: Phosphoglyceride crystal deposition disease (PCDD) is an extremely rare condition characterized by the deposition of phosphoglyceride crystals, occasionally forming tumor like lesions that present significant diagnostic challenges. Here, we report, to our knowledge, the first documented recurrent case of PCDD confined to the mandible, which clinically and radiologically mimicked a malignant bone tumor. <b>Case Presentation</b>: An 80-year-old female patient presented with a progressively enlarging mandibular mass, and imaging studies demonstrated an osteolytic lesion with cortical bone destruction and marked fluorodeoxyglucose uptake on positron emission tomography-computed tomography, raising a strong suspicion of malignancy. Histopathological examination revealed foreign-body granulomatous inflammation with characteristic crystal deposition, and the diagnosis of PCDD was definitively established through the combined use of gold hydroxamic acid staining, Raman spectroscopy, and ultrastructural analysis. Although surgical excision with curettage was initially achieved, local recurrence was observed 6 years later, indicating the potential for long-term disease persistence. In addition, a comprehensive literature review conducted in accordance with the PRISMA guidelines was performed to summarize previously reported cases of PCDD, with particular attention to anatomical distribution, radiological characteristics, recurrence patterns, and proposed pathogenic mechanisms. The review confirmed the extreme rarity of mandibular involvement and demonstrated that recurrence can occur apparently even after surgical treatment. <b>Conclusions</b>: This case underscores the importance of a multimodal diagnostic strategy integrating imaging, histopathology, and spectroscopic analyses for the accurate identification of PCDD and highlights the necessity of histopathological confirmation to prevent unnecessary aggressive treatment.