Paraneoplastic pemphigus caused by pre-existing stroma-rich variant of Castleman disease: from a pathologist’s point of view

Abstract

A young woman presented with mucocutaneous blisters and ulcerating lesions, and was diagnosed with erythrodermic pemphigus complicated by bronchiolitis obliterans. Her clinical condition did not improve on immunosuppressive therapy. She had a history of an asymptomatic retroperitoneal mass, presumed to be a dermoid cyst, followed up clinically. Due to the pre-existing nature of the retroperitoneal mass, the paraneoplastic nature of the pemphigus was initially not recognised, but after a multidisciplinary team meeting a biopsy was performed. Histology revealed a rare stroma-rich variant of Castleman disease with a prominent stroma demonstrating a myoid phenotype. Resection of the retroperitoneal tumour resulted in resolution of the cutaneous blisters. This emphasises the importance to consider paraneoplastic disease in treatment-resistant pemphigus as surgical removal of the tumour forms the mainstay of therapy. The differential diagnosis should include Castleman disease and careful evaluation of histology is essential with the awareness of this rare stroma-rich variant.

Case report: The stroma-rich variant of Castleman’s disease of hyaline-vascular type with atypical stromal cell proliferation and malignant potential: An exceptional rare case occurred in mediastinal lymph node

“…By definition, the area of interfollicular zone is required to be larger than that of follicular zone. Since then, a few studies further explored the clinicopathological features of this rare disorder ( 5 – 12 ). However, the etiology of SR-HVCD is still kept unknown.…”