Department of Oral and Maxillofacial Surgery, Chubu Tokushukai Hospital, 801 Higa, Kitanakagusuku, Nakagami-gun, Okinawa-ken, 901-2393, Japan.
Department of Oral and Maxillofacial Functional Rehabilitation, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nakagami, Nishihara, Okinawa, 903-0215, Japan.
BMC Oral Health. 2022 Dec 31;22(1):662. doi: 10.1186/s12903-022-02695-0.
The coexistence of calcium pyrophosphate dihydrate crystal deposition (CPP) and synovial chondromatosis (SC) in the temporomandibular joint (TMJ) is rarely reported. CPP disease (CPPD) is complex arthritis synonymous with excessive pyrophosphate production and variable aberrations in mineral and organic phase metabolism of the joint cartilage, leading to local inundated CPP and crystal deposition of partially deciphered predispositions. Meanwhile, SC is a rare benign synovial joint proliferative disease of unclear etiology and has a low risk of malignant transformation. However, SC manifests severe joint disability and dysfunction because of connective tissue metaplasia of the synovial membrane, which forms cartilaginous nodules with or without calcifications or ossifications. These nodules often detach and form intra-articular loose bodies and very rarely within extraarticular spaces.
We report the case of a 61-year-old man to expand the body of literature on these unusual coexisting arthropathies of the TMJ. The patient presented to our hospital in 2020 with complaints of pain in the right TMJ and trismus for over 6 months. Radiographic assessments of the TMJ provided a preoperative provisional diagnosis of SC. However, the histopathology of the open biopsy revealed tumor-like lesions comprising several deposits of rhomboid and rod-shaped crystals that displayed positive birefringence in polarized light, confirming a coexistence of CPPD. A second-stage operation was performed for the complete removal of the loose bodies and chalk-like lesions including synovectomy. No evidence of recurrence was recorded after a follow-up of nearly 1.5 years.
Isolated CPPD and SC of the TMJ are prevalent in the literature however, monoarticular coexistence of these diseases is rare, due to the lack of consistency in the diagnostic criteria in clinical practice. Moreover, optimal treatment depends on several considerations. This report delineated the molecular etiopathology and underscored the need for continued deciphering of the causal mechanisms of coexisting CPPD and SC of the TMJ. In addition, the importance of confirmatory testing for accurate diagnosis, and appropriate management of these diseases were discussed.
双水相萃取技术（CPP）和滑膜软骨瘤病（SC）在颞下颌关节（TMJ）中同时存在的情况很少见。CPP 病（CPPD）是一种复杂的关节炎，与过量焦磷酸盐的产生以及关节软骨中矿物质和有机相代谢的可变异常有关，导致局部 CPP 浸润和部分解密的局部 CPP 晶体沉积。同时，SC 是一种罕见的良性滑膜关节增生性疾病，病因不明，恶性转化风险低。然而，由于滑膜膜的结缔组织化生，SC 表现为严重的关节残疾和功能障碍，形成带有或不带有钙化或骨化的软骨结节。这些结节经常脱落并形成关节内游离体，非常罕见的情况下也会形成关节外间隙。
我们报告了一例 61 岁男性患者的病例，以扩展 TMJ 这些罕见共存关节病的文献。该患者于 2020 年因右 TMJ 疼痛和张口受限超过 6 个月就诊于我院。TMJ 的影像学评估提供了 SC 的术前暂定诊断。然而，开放性活组织检查的组织病理学显示，肿瘤样病变包括几个菱形和杆状晶体的沉积，在偏光下显示出阳性双折射，证实了 CPPD 的共存。为了完全切除游离体和粉笔样病变，包括滑膜切除术，进行了二期手术。在近 1.5 年的随访中，未记录到复发证据。
TMJ 的孤立 CPPD 和 SC 在文献中很常见，但是由于临床实践中诊断标准缺乏一致性，这些疾病的单关节共存很少见。此外，最佳治疗取决于多种因素。本报告阐述了分子发病机制，并强调了继续破译 TMJ 共存 CPPD 和 SC 的因果机制的必要性。此外，还讨论了确诊测试对准确诊断和这些疾病的适当管理的重要性。
