Unicentric or Multicentric Castleman disease?
A 52 year old caucasian woman, with history of ovarian pelvic pain and without any systemic symptoms, underwent a transvaginal ultrasonography, in which was detected a right ovarian enlargement. Computed tomography revealed a 4.7 cm sized intraperitoneal pelvic solid mass, with regular but bumped margin with some calcifications spots and an isolated right external iliac lymph node enlargement. Due to shape, location and unknown nature of the mass, the patient had a whole body PET which showed metabolic activity in both pelvic mass and enlarged omolateral lymph node. In another center, was performed a biopsy of the right adnexal mass that resulted undiagnostic. Then the patient underwent an explorative laparoscopic surgery with excision of the pelvic mass at our hospital. At histological examination, the excised mass revealed to be a lymph node, with peculiar histopathologic changes suggestive for the diagnosis of hyaline-vascular type Castleman disease. Castelman Disease is a lymphoid disorder characterized by the presence of hypervascular lymph node. Two different forms of the disease are known: the Unicentric Castelman Disease is a benign disorder, that consists in a single lymphoid mass, more often localized into the mediastinum and the Multicentric Castleman Disease that involves more than one lymphoid station and that is related to the presence of B symptoms (fevers, night sweats and weight loss), HIV/HHV8 infection and increases of IL-6 sieric levels. In this patient, blood analysis revealed mild reduction of WBC with neutropenia and lymphopenia, mild increase of light chain K and of K/λ rate, normal levels of LDH and β2 microglobulin. Immunostainig and urine exam were negative, but a mild increased of sieric level of IL-6 was detected. Serologies for HIV, HCV, HBV and HHV8 were negative. These finding were unclear to confirm univocally Unicentric CD, so two month later it was performed another CT than reveal persistence of right external iliac lymph node enlargement, but this lesion did not show metabolic activity at a second whole body PET done after surgical excission of the mass. In conclusion, when a single abdominal-pelvic mass is detected at CT in asymptomatic patients, Unicentric Castleman disease should be taken in consideration in the differential diagnosis and differentiated from metastatic disease, lymphoproliferative disorders and other hypervascular masses.