Tangles in smears of granulomatous lymphadenitis--a clue to the diagnosis

To assess the significance and nature of tangles in fine needle aspiration biopsy (FNAB) smears of granulomatous lymphadenitis.

The study group included 45 cases of clinically suspected granulomatous lymphadenitis particularly of tuberculous origin in which a cytologic diagnosis of granulomatous lymphadenitis (GL) was made on FNAB material. Smears of 21 lymph node aspirates without cytologic evidence of granulomatous disease (NGL) were included as a control group. One case with double pathology was excluded. All smears were fixed in 95% alcohol and stained with haematoxylin and eosin. Tangles were defined as a meshwork of haematoxyphilic string-like material occurring in a tangle in an otherwise well preserved smear. A score was given for the distribution (0-3) and density (1-3) of the tangles on the count of 10 high power fields for each aspirate. Statistical analysis was done by the Mann Whitney U test.

Tangles were present in 41 of 45 (91%) GL and 7 of 21 (33%) NGL. The differences were statistically significant (p = 0.0008 and 0.0001 for distribution and density respectively). Six of the seven (84%) NGL with tangles were either cytologically diagnostic or suspicious of malignancy with 5 (71%) showing features of non-Hodgkin's lymphoma. The tangles were positive for nuclear stains (Feulgen) and originated in the nuclei of both lymphocytes and epithelioid cells, probably due to easy fragility of altered nuclear material.

The presence of tangles in smears should raise the possibility of GL in the absence of a malignancy, specifically a lymphoma. This becomes an important diagnostic clue especially in situations where epithelioid histiocytes, the hall mark of GL, are sparse or absent in cytologic material.