Relapsing Polychondritis following PD-1 Blockade by an Immune Checkpoint Inhibitor.

Immune-related adverse events (irAEs) mimicking rheumatic diseases are observed in 1.5%-22% of patients receiving cancer therapy with immune checkpoint inhibitors (ICIs). Relapsing polychondritis (RP) is a rare autoimmune disease mainly involving auricle, nose, and airway cartilage inflammation. However, knowledge regarding RP as an irAE is scarce. Pembrolizumab, a type of ICI that regulates the programmed cell death protein-1 (PD-1), is used in patients whose cancer cannot be cured with surgery or radiation therapy. We report the first case of pembrolizumab-induced RP with isolated auricular lesions resolved without immunosuppressants. A 49-year-old man with lower lip cancer underwent surgical resection followed by reconstruction. Histopathological investigation confirmed the diagnosis of squamous cell carcinoma. Since multiple metastases 6 months post-surgery rendered the carcinoma inoperative, pembrolizumab was initiated, improving lymph node involvement. However, 4 months later, the patient developed rapidly progressive swelling and pain in both auricles. While no pathogen was detected, C-reactive protein levels were elevated (11.21 mg/dL). Computed tomography (CT) showed swelling of the bilateral auricles; the biopsy of the right auricle revealed cartilage destruction by infiltration of surrounding granulation tissue. Since these characteristic findings were not observed before pembrolizumab was initiated, we clinically diagnosed the patient with RP induced by pembrolizumab. The swelling of the auricles resolved spontaneously 1 month after pembrolizumab discontinuation. 18F-fluorodeoxyglucose (18F-FDG)-positron emission tomography/CT revealed no 18F-FDG uptake in reduced auricular lesions. On re-administration of pembrolizumab to maintain antitumor immunity, both auricles swelled again, and pembrolizumab was switched to paclitaxel, considering the risk of tracheobronchial chondritis. Although no recurrence of auricular chondritis was observed, the patient died from cancer progression 8 months after paclitaxel administration. RP can occur as a rheumatic irAE in patients receiving anti-PD-1 therapy, and a literature review with retrospective analysis indicates that PD-1 inhibition-induced RP is unusual and atypical.

Cases of true and false median cleft with polypoid masses in the facial midline.

We describe cases of true and false median cleft combined with polyps. The polyp in the true median cleft was microscopically a skin polyp consisting of fatty tissue and was considered to be subsequent compensatory partial excess caused by impediment at the embryonic stage. The polyp in the false median cleft was considered to be a failure of the nasal septum derived from the nasal (ectethmoid) capsule. The features of these cases were considered of interest because they exhibited transient forms of the cleft. The histological findings of each polyp reflected the distinctive features of each median cleft.

A missense mutation in the SH3BP2 gene on chromosome 4p16.3 found in a case of nonfamilial cherubism.

OBJECTIVE: Cherubism is a rare hereditary multilocular cystic disease of the jaws, characterized by its typical appearance. Although nonfamilial cases have been reported, it is difficult to distinguish nonfamilial cherubism from central giant cell granuloma. Recent studies have revealed the point mutations in the SH3BP2 gene on chromosome 4p16.3 in cherubism families. In this article, the SH3BP2 gene in nonfamilial cherubism was examined. PATIENT: A 21-year-old Japanese woman with nonfamilial cherubism. INTERVENTIONS: Genomic DNA was purified from a blood sample obtained from the patient and used for direct sequencing. In addition, a sample of the lesion, resected during surgery, was used for histologic and immunohistochemical purposes. RESULTS: Genomic DNA sequencing found a Pro418Arg mutation in the SH3BP2 gene of the patient. In a histochemical analysis, the multinucleated giant cells proved to be strongly positive for PGM-1, KP-1, and tartrate-resistant acid phosphatase and faintly positive for osteopontin. CONCLUSIONS: The missense mutation Pro418Arg was identified in the SH3BP2 gene from a nonfamilial case of cherubism. DNA diagnosis may play a significant role in the identification of cherubism.