Localized light chain amyloidosis: A self-limited plasmacytic B-cell lymphoproliferative disorder

Localized light chain amyloidosis involving the lacrimal sac: A case report

Amyloidosis involving the lacrimal sac is extremely rare. In this study, we demonstrated a rare case of localized light chain amyloidosis in the lacrimal sac region. The lacrimal sac lesion presented as infiltrative with bony erosion. Given the slow growth of the lesion and the absence of a blood flow signal inside, we concluded that the lesion was less likely to be malignant. Complete removal of the lacrimal sac lesion combined with simultaneous lacrimal passage reconstruction was performed. The diagnosis of light chain amyloidosis was confirmed by histology. The surgical results were favorable, and no recurrence was observed over one-year follow-up. Our case report enriches the understanding of amyloid deposition in the ocular adnexa.

Role of EBUS-TBNA/EUS-FNA and mass spectrometry for diagnosis and typing of lymph node amyloidosis: 10-year experience in two tertiary care academic centers

BACKGROUND

The objectives of this study were to investigate the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)/endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for the diagnosis of amyloidosis coupled with the feasibility of mass spectrometry (MS) for amyloid subtyping.

METHODS

All patients who had amyloid diagnosed by EBUS-TBNA/EUS-FNA at two tertiary care centers from 2011 to 2020 were retrieved along with the MS subtype, clinical findings, and outcomes.

RESULTS

Eight patients were included: seven underwent EBUS-TBNA of mediastinal lymph nodes, and one underwent EUS-FNA of a periportal lymph node. Ages ranged from 37 to 79 years (median, 69 years), with equal numbers of men and women. Presenting clinical history included one case each of follicular lymphoma, lymphoplasmacytic lymphoma, rheumatoid arthritis, possible sarcoid, cirrhosis, and chronic renal insufficiency, and one case each of suspected pulmonary and cardiac amyloidosis. All cases showed waxy, amorphous material on direct smears (n = 5) or ThinPrep slides (n = 3), which were confirmed as amyloid on Congo Red staining. Immunohistochemistry showed dominant lambda staining in two of three cases. MS was performed in all cases and identified five of the light-chain (AL) type, one of the heavy-chain/AL type, and two suggestive of AL amyloidosis. Bone marrow biopsy performed in seven patients demonstrated that three had monoclonal plasma cells and one had lymphoplasmacytic lymphoma. Two of four patients with systemic amyloidosis received chemotherapy and remained alive, whereas three with localized disease remained stable under observation.

CONCLUSIONS

EBUS-TBNA/EUS-FNA is effective for amyloidosis diagnosis and provides adequate material for ancillary tests, including MS, which can identify the precursor amyloidogenic protein, leading to appropriate patient management.