Keywords
endosonography - tuberculosis - kala-azar - lymph nodes - fine needle aspiration
Introduction
Visceral leishmaniasis (VL) or Kala-azar is a disseminated protozoan infection that
spreads via the bite of phlebotome sand flies and is caused by Leishmania sp.[1] The disease onset is usually insidious and typical manifestation of VL include slow
progression of malaise, fever, weight loss, and hepatosplenomegaly.[1] Kala-azar (“black feverâ€) refers to the dark color of skin seen in patients with
VL and is usually seen in patients in South Asia but not elsewhere.[2] Lymphadenopathy is usually reported in cases of VL from East African countries and
is rarely reported from India.[3] VL is usually diagnosed by demonstrating parasites in the bone marrow or splenic
aspirate, and fine-needle aspiration (FNA) from enlarged lymph nodes has been occasionally
reported for its correct diagnosis.[1]
[3] We report an interesting case of VL presenting with malaise, fever and weight loss
along with isolated mediastinal lymphadenopathy and mimicked tuberculosis. Absence
of spleen because of previous splenectomy for symptomatic portal hypertension led
to difficulty in establishing the correct diagnosis that was eventually established
by endoscopic ultrasound (EUS)-guided FNA.
Case Report
A 34-year-old male, who had undergone splenectomy with proximal lienorenal shunt 12 years
ago for variceal bleeding because of extrahepatic portal venous obstruction, was admitted
with a 2-month history of fever, fatigue, and weight loss. The general physical examination
revealed a thin built patient with no organomegaly or lymphadenopathy. The hematological
investigations revealed hemoglobin of 8.2 g/dL, total leukocyte count of 5,200 cells/μL,
and platelet count of 1.3 lac/μL. Blood cultures as well as tests for human immunodeficiency
virus (HIV) were negative. Chest X-ray did not reveal any abnormal findings. Liver
function tests revealed conjugated hyperbilirubinemia (total/conjugated: 2.5/1.9 mg/dL),
elevated alkaline phosphatase (3,326 U/L; normal: <128 U/L), low-serum albumin (2.8
g/dL; normal 3.4–4.8 g/dL), and elevated serum globulins (4.6 g/dL; normal 2.0–3.5
g/dL). Abdominal ultrasonography revealed dilated intrahepatic biliary radicles due
to portal cavernoma cholangiopathy (PCC). There were no gastroesophageal varices on
gastroscopy.
EUS done for evaluation of PCC revealed enlarged hypoechoic subcarinal as well as
aortopulmonary lymph nodes with areas of necrosis ([Fig. 1], arrows). EUS-guided FNA was performed using 22G EUS FNA needle (EchoTip, Wilson-cook
Medical, Winston-Salem, North Carolina, United States) ([Fig. 2]), and cytological examination of lymph node aspirate revealed collection of foamy
histiocytes, showing numerous amastigote forms of Leishmania donovani ([Fig. 3]: MGG x40). Higher magnification revealed multinucleated histiocyte, showing Leishmania
donovani (LD) bodies ([Fig. 4]) and safety pin-shaped LD bodies with kinetoplasts within a histiocyte ([Fig. 5]; arrows [MGG x100]). RK 39 serological test was positive. Patient was successfully
treated with liposomal amphotericin B.
Fig. 1 Endoscopic ultrasound (EUS): enlarged hypoechoic subcarinal lymph node with areas
of necrosis.
Fig. 2 Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) was performed using
22G EUS FNA needle.
Fig. 3 Cytological examination of lymph node aspirate revealed collection of foamy histiocytes,
showing numerous amastigote forms of Leishmania donovani (MGG × 40).
Fig. 4 Multinucleated histiocyte showing Leishmania donovani (LD) bodies (MGG × 100).
Fig. 5 Safety pin-shaped Leishmania donovani (LD) bodies with kinetoplasts within a histiocyte
(arrows [MGG × 100]).
Discussion
Patients with VL in India usually present with fever, weight loss, hepatomegaly, splenomegaly,
pancytopenia, and hyperglobulinemia. Enlarged firm spleen in patient with febrile
illness from an endemic area raises suspicion of VL. Our patient had undergone splenectomy
for symptomatic extrahepatic portal venous obstruction and did not reside in the endemic
area for VL. Therefore, Kala-azar was not considered as a differential diagnosis in
the index case. Also, the clinical presentation as well as EUS morphology of mediastinal
lymph nodes mimicked lymph nodal tuberculosis.[4]
[5]
Lymphadenopathy due to Kala-azar is rare in India and isolated mediastinal lymphadenopathy
in the absence of HIV infection is very rarely reported in VL.[6]
[7] VL is commonly diagnosed by demonstrating parasites in the bone marrow and splenic
aspirate and lymph node FNA has been rarely used for its diagnosis.[1]
[2]
[3] Most of the cases of lymph nodal leishmaniasis have been diagnosed by aspiration
of cervical lymph nodes or ultrasound-guided FNA of mesenteric lymph nodes.[1]
[2]
[3] The diagnosis of VL by EUS-guided FNA of mediastinal lymph nodes is rarely reported
in the literature.[6]
[7]
In conclusion, leishmaniasis should be included in differential diagnosis of unexplained
lymphadenopathy, especially in endemic areas. EUS-guided FNA is an useful modality
for correctly diagnosing unexplained mediastinal lymphadenopathy.
