Diagnostic dilemma: Kikuchi's disease or tuberculosis?

Any patient from a tuberculosis (TB) endemic area such as India with classical clinical features of fever, weight loss and lymphadenopathy, making a diagnosis of Kikuchi's disease (KD) prior to waiting for the 6-week culture is not appropriate. KD or histiocytic necrotising lymphadenitis is a rare self-limiting cervical lymphadenitis, often a diagnosis of exclusion. One needs to exclude TB, sarcodosis, lymphoma and autoimmune diseases to make such a diagnosis. The patient here with classical clinical presentation of TB with lymph node biopsy mimicking KD (biopsy and immunohistochemistry) posed a big diagnostic dilemma. However, culture of the biopsied lymphatic tissue was confirmed to be mycobacterium TB after the 6th week of incubation. The patient was treated with antitubercular drugs initially, and later, steroid was added in view of his persistent symptoms and he responded. One should wait for the tissue culture report to confirm or exclude the diagnosis of TB. Exclusion should not be based only on laboratory criteria. Histopathogically, TB can mimic any other granulomatous disorder.