A case report of Castleman disease with paraneoplastic pemphigus and bronchiolitis obliterans: Challenges and key takeaways.

introductionCastleman disease is a rare lymphoproliferative disorder, subdivided into three types: unicentric Castleman disease, idiopathic multicentric Castleman disease and human herpesvirus-8 (HHV8) associated multicentric Castleman disease. The retroperitoneum comprises only 13 % of the cases. CASE PRESENTATION: We report a case of a 36-year-old female who presented with skin lesions in a dermatology clinic. Her CT scan revealed a left retroperitoneal soft tissue mass that measured 5.6 × 7.8 × 6.7 cm. On laparoscopy, a 10 × 5 cm retroperitoneal mass located in close proximity to the left renal vessels was noted. Histopathology revealed dense lymphoid infiltrate with follicular hyperplasia having atretic germinal centres, confirming the diagnosis of Castleman disease. DISCUSSION: Paraneoplastic pemphigus (PNP) and bronchiolitis obliterans (BO) are complications associated with Castleman disease. PNP is always associated with an underlying neoplasm and diagnosis of PNP should prompt work up for underlying malignancy. BO is a progressive and debilitating condition that responds poorly to medical therapy and lung transplant is the only viable treatment option. On account of vascular nature of these lesions, pre operative embolization should be considered. Ureteric stenting may also be helpful to delineate ureters while dissecting retroperitoneal mass.

conclusionMucocutaneous lesions suspicious for PNP should be thoroughly investigated and necessary imaging must be obtained to look for underlying neoplastic process. CT scan is an effective diagnostic modality; however, it has its limitations and PET/CT may provide additional benefits in diagnosis. Prior to resection, careful surgical planning, including ureteric stenting and pre-operative embolization may be required.