Rheumatoid nodules: a narrative review of histopathological progression and diagnostic consideration

Sulfasalazine's potential in managing rheumatoid nodules: Insights from a case report

RATIONALE

Rheumatoid arthritis (RA) is a systemic inflammatory disease characterized by joint inflammation and various extra-articular manifestations, including rheumatoid nodules (RNs). This case study aims to explore the effectiveness of alternative treatments for RNs, particularly highlighting the therapeutic potential of sulfasalazine.

PATIENT CONCERNS

A 52-year-old male with established RA presented with worsening joint pain and firm nodules on his elbows, feet, and fingers.

DIAGNOSES

The patient fulfilled the diagnostic criteria for RA and was diagnosed with methotrexate-induced RNs based on their temporal association with methotrexate initiation.

INTERVENTIONS

Methotrexate was discontinued and a combination of leflunomide and sulfasalazine was initiated. Sulfasalazine led to improvement in both joint pain and nodule size. However, due to cost concerns, the patient discontinued sulfasalazine, resulting in a resurgence of both symptoms and nodule enlargement. Reintroduction of methotrexate resulted in significant improvement in joint inflammation, and notably, no new nodules developed at 6 months follow-up.

OUTCOMES

Sulfasalazine demonstrated efficacy in managing RA nodules, suggesting a potential alternative therapy.

LESSONS

The case highlights the complex etiology of nodules in RA and emphasizes the importance of individualized treatment approaches and close monitoring for optimal management.

Caplan Syndrome Mimicking Progressive Massive Fibrosis on CT: A Case Report

This report presents a unique case of Caplan syndrome that mimicked accelerated progressive massive fibrosis. The patient, a former coal miner, had been diagnosed with coal worker's pneumoconiosis 15 years prior and had been treated for rheumatoid arthritis for over 20 years. Accelerated progressive massive fibrosis and the development of multiple nodules with cavitation in the basal lungs were subsequently observed on serial CT scans. Here, the CT manifestations of Caplan syndrome are highlighted in a case in which Caplan syndrome mimicked accelerated progressive massive fibrosis.

Spinal calcifying pseudoneoplasm of the neuraxis (CAPNON) associated with facet joint pathologies: CAPNON diagnostic and pathogenic insights

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumor-like fibro-osseous lesion that can develop anywhere in the neuraxis. Approximately a half of reported CAPNONs developed in the spinal region, mostly close to the facet joint (FJ). The diagnosis of spinal CAPNONs is challenging given the existence of mimics and associated pathologies including calcific degeneration of the FJ ligaments (DFJL) and synovial cysts (SCs). The pathogenesis of CAPNON remains elusive, although there have been a few hypotheses including degenerative, reactive, proliferative and immune-mediated processes. Our present study examined clinical, radiological and pathological features of 12 spinal CAPNONs in comparison to 9 DFJL foci, and diagnostic and pathogenic relationship between CAPNONs and FJ pathologies. On imaging, CAPNONs were all tumor-like and typically bigger than DFJL foci. All CAPNONs showed pathologically diagnostic features including characteristic cores, consistently identifiable core-surrounding/peripheral palisading of macrophages and other cells including multinucleated giant cells, variable infiltration of CD8+ T-cells, and multifocal immunopositivity of neurofilament light chain (NF-L). These features were absent or limited in the DFJL foci with statistically significant differences from CAPNONs, except calcifications. Spinal CAPNONs co-existed with DFJL foci in all cases; some had transitional foci with overlapping focal CAPNON and DFJL-like features. These findings, along with our previously reported relationship between CAPNONs and SCs, suggest that spinal CAPNONs may occur in association with or in transition from calcifying/calcified degenerative lesions of FJ ligaments and/or SCs when a reactive proliferative process is complemented by other pathogenic changes such as immune-mediated pathology and NF-L deposition/expression.