Castleman's disease of the parotid.

A 17-year-old male presented with a painless swelling in the right parotid region of 2 years duration. The swelling was progressively increasing in size. On examination there was a round, firm, smooth-surfaced and non-tender swelling in the right infra-auricular region. CT scan revealed a smooth well-defined mass with a lobulated surface and homogeneous soft tissue density. Clinical differential diagnosis included benign salivary gland tumours. Fine needle aspiration was done from the swelling. Smears showed reactive population of lymphoid cells in various stages of maturation along with a few clusters of benign ductal epithelial cells, suggesting the diagnosis of reactive lymphoid hyperplasia of intra-parotid lymph node. Subsequently, the patient underwent superficial parotidectomy and the specimen was sent for histopathological examination. It was a single globular soft tissue mass measuring 4.5 x 4 x 3 cm. Cut section showed a well-defined homogeneous greyish brown mass surrounded by a thin rim of normal salivary gland tissue. Microscopically, the lesion was composed of lymphoid follicles of varying sizes with atrophic germinal centres traversed by hyalinised vessels (Figure 1). Mantle zone lymphocytes showed characteristic concentric onion skinning around the atrophic germinal centres (Figure 2). There was prominent vascular proliferation in the interfollicular area. A few ductal epithelial cells in the form of salivary inclusions representing embryologic remnants were also seen. Normal compressed salivary tissue was identified at the periphery (Figure 3). On the basis of these findings, a diagnosis of Castleman’s disease (hyaline vascular type) of intra-parotid lymph node was made.