Iwata Hajime, Nakashima Jotaro, Kai Tomonori, Okada Haruka
Pathology, Tokyo Metropolitan Tama Medical Center, Fuchu, JPN.
Cureus. 2024 Dec 5;16(12):e75179. doi: 10.7759/cureus.75179. eCollection 2024 Dec.
Pulmonary amyloidosis is diagnosed by identifying amyloid deposits using Congo red stain (CR) and birefringence under polarized light. However, collagen fibers can also produce similar staining results, complicating diagnosis. We report a case of a 55-year-old male patient with lung opacities, initially suspected to have amyloidosis based on CR positivity and green birefringence. Thoracoscopic biopsy revealed pulmonary ossification (PO) rather than amyloidosis. The parallel alignment of lamellar bone fibers likely caused false-positive CR findings and birefringence. This case underscores the need for careful differentiation between bone tissue and amyloid deposits. Misdiagnosis can lead to unnecessary treatments, especially when the actual condition requires only conservative management, as in PO. Awareness of PO as a mimic of amyloidosis is crucial, especially in cases lacking other systemic symptoms or calcification.
肺淀粉样变性通过使用刚果红染色（CR）并在偏振光下观察双折射来识别淀粉样沉积物进行诊断。然而，胶原纤维也可产生类似的染色结果，使诊断复杂化。我们报告一例55岁男性患者，有肺部混浊，最初基于CR阳性和绿色双折射怀疑患有淀粉样变性。胸腔镜活检显示为肺骨化（PO）而非淀粉样变性。板层骨纤维的平行排列可能导致CR检查结果和双折射出现假阳性。该病例强调了仔细区分骨组织和淀粉样沉积物的必要性。误诊可能导致不必要的治疗，特别是当实际病情仅需要保守治疗时，如PO。认识到PO可模拟淀粉样变性至关重要，尤其是在缺乏其他全身症状或钙化的病例中。
