A 32-year-old male presented to the surgical clinic with multiple left axillary lymph nodes. His complaints had been persistent for the previous eight months and had been preceded by development of furuncles in the axilla. Although he had infrequently taken treatment from several practitioners, there was no relief to his complaints. He subsequently developed fever ranging from 100-101  F. There was no family or past history of tuberculosis or loss of weight or appetite. Jaundice was not present.
The patient had a negative Montoux test. Hematological evaluation revealed a raised erythrocyte sedimentation rate (ESR) of 28 mm in the first hour by the Wintrobes method. Other hematological parameters, including a coagulation profile, were normal. The chest radiograph did not reveal any abnormality. Liver function tests showed the total bilirubin level to be 0.7 mg/dL, serum alkaline phosphatase was 52 U/L, and serum alanine and aspartate aminotransferases were 21 U/L and 28U/L, respectively. The patient was referred to the Department of Pathology for FNAC, with a provisional diagnosis of tuberculosis, a disease rampant in rural as well as urban India. On palpation, three lymph nodes were discernible in the left central axilla which were discrete, firm, and mobile, ranging in size from 0.8 to 2.0 cm, with pain in the largest one. FNA was performed on the largest lymph node.
A blood-tinged caseous aspirate was obtained and several fixed and dry smears were prepared, which were stained with hematoxylin and eosin, Giemsa, and Ziehl Neelson (ZN) stains.
Smears were cellular showing intact and degenerated neutrophils, histiocytes, and eosinophils, along with several loose epithelioid cell granulomas, giant cells, and a variable number of lymphoid cells [Figure 1a]. The background showed extensive caseous necrosis. When the ZN stained smears were being screened for the presence of acid fast bacilli, classical hooklets of Echinococcus were noticed [Figure 2a]. The hooklets were semi-translucent, retractile, and sickle-shaped, with an inner semi-translucent core of a similar shape. Alerted by this discovery, a further search revealed scolices of Echinococcus, which were large ovoid structures [Figure 2b]. However, no lamellated membrane was identified. In addition, classic granular, beaded, acid fast bacilli of Mycobacterium tuberculosis were seen [Figure 1b]. This enabled us to render a diagnosis of tuberculous lymphadenitis with coexistent echinococcal infection.
An ultrasound of the abdomen was unremarkable. Contrast-enhanced computed tomography was advised for the chest as well as liver, which the patient could not afford. The echinococcal indirect hemagglutination test was negative. Retrospectively, the patient gave a history of contact with a dog. Polymerase chain reaction as well as culture for Mycobacterium tuberculosis was positive. Antihelminthic as well as anti-tuberculous therapy was started. However, the excision could not be performed as the patient was lost to follow-up.