Multicentric Castleman Disease with Complete Duodenal Obstruction in an HIV Patient
Authors: Sethi Tarsheen K , Alireza Abdolmohammadi , Kloecker Goetz H , Slone Stephen P 
Published: October 2019

Abstract
Abstract 4834
Multicentric Castleman's Disease(MCD) can have an aggressive course making early diagnosis and treatment important. Although rare, peripancreatic involvement is known in Castleman's disease and an unusual presentation should be considered especially in the setting of HIV. An excisional lymph node biopsy is required for diagnosis. High plasma titers of Human Herpes Virus 8 DNA should also raise this possibility. Coexistence of Castleman disease and body cavity lymphoma has been reported but is rare.

Case Presentation:
A 42 year old African American gentleman with a history of HIV and CD4 count 271 presented with intractable nausea and vomiting of 1 month duration; associated with epigastric pain and weight loss. Past history was significant for presentation with jaundice 6 months earlier when he was found to have a pancreatic head mass with portocaval and retroperitoneal lymphadenopathy raising the suspicion of pancreatic adenocarcinoma. Endoscopic ultrasound guided fine needle aspiration of the mass had revealed a poorly differentiated malignant neoplasm that could not be further characterized by immunohistochemistry. Considering the HIV status of the patient, there was a strong suspicion of lymphoma. A PET-CT was planned to identify an appropriate site for tissue diagnosis but the patient was lost to follow up. Repeat imaging during the current admission revealed increasing size of the pancreatic mass causing complete obstruction of second part of duodenum. The patient subsequently underwent gastro-jejunostomy to bypass the duodenal obstruction and an excisional biopsy of two mesenteric lymph nodes was performed during the procedure. Pathology revealed HHV-8 positive plasma cell variant of Castleman's disease. Patient also had high plasma titers of HHV-8. Furthermore, the patient was also found to have bilateral pleural effusions and a thoracentesis was performed. Pleural cytology revealed large plasmablastic lymphoid cells that were positive for HHV-8, CD30, CD45, CD138, Ebstein-Barr virus (EBV), epithelial membrane antigen, and multiple myeloma oncogene-1. These findings suggested a diagnosis of body cavity lymphoma.

Discussion:
Although rare, the association of Multicentric Castleman's disease (MCD) with HIV is well recognized. The incidence is independent of CD4 count and the use of HAART. There are isolated case reports of pancreatic involvement with Castleman's disease and only one involving the duodenum. While most patients with peripancreatic involvement presented with abdominal discomfort, nausea or systemic symptoms, our patient was severely symptomatic from complete duodenal obstruction. Our case also highlights that the diagnosis can be elusive and requires excisional lymph node biopsy. Moreover, HIV MCD is fluorodeoxyglucose avid, and a PET-CT may help identify the gland to biopsy next in difficult to diagnose cases. Body cavity lymphoma is also HHV-8 related and this diagnosis should be considered in any HIV patient with effusions. Pleural fluid cytology and immunohistochemistry usually clinch the diagnosis.

Disclosures:
No relevant conflicts of interest to declare.