Diverse liver morphology in two cases of visceral leishmaniasis: Same face,different expressions

Introduction

Infection with Leishmania donovani in Visceral Leishmaniasis (VL) affects the reticulo-endothelial (RE) cells of spleen, liver, mucosa of small intestine, bone marrow and lymph nodes. ¹ In endemic regions, the diagnosis is confirmed by detecting the parasite in infected tissue and the first recommended option is bone marrow aspiration (BMA), as it is easy to perform and gives a parasitic yield. ² We report two cases, who presented with pyrexia of unknown origin, where BMA was negative and the diagnosis was made on liver biopsies (LB). The diverse histopathological features in two cases are discussed.

Case reports

Case 1

A 52-year-old man from a non-endemic area of North India presented with high-grade fever for one month’s duration, not associated with cough, chills rigor nor jaundice. He also complained of loss of appetite without significant loss of weight. There were no gastrointestinal, urinary or neurological symptoms. There was no history of skin rash, animal contact or recent travel. He had no other co-morbidity. On examination, mild pallor was noted with a minimal icterus. Abdominal examination revealed minimal hepatomegaly and mild splenomegaly. There was no central nervous system or genitourinary symptoms.

Investigation results of both cases are summarised in Table 1.

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Table 1.

Investigation results of both case 1 and case 2.

Blood tests	Case 1	Case 2
Haemogram	Mild anaemia	Pancytopenia
PBS for malarial parasite	−	−
ESR	96 mm in 1 h	140 mm in 1 h
Mountoux test	−	−
LFT-Bil/AST/ALT	30.8 µmol/L, 3.3 µkat/L, 1.4 µkat/L	138.3 µmol/L, 5.1 µkat/L, 3.8 µkat/L
Etilogical work up for liver disease	−	−
KFT	Normal	Normal
Blood culture (bacterial/AFB)	−	−
BMA organisms/LD bodies	Normal marrow	Hyperplastic marrow
Serology
Antinuclear antibody	X	+ (1:100) further dilution not done
Coombs test	X	+
Rh factor/DS DNA	X	−
Widal test	−	−
HIV	−	−
Leishmania serology	+ (done after liver biopsy)	−
Dengue/Brucella serology	−	−
Leptospira serology	−	X
Scrub typhus/Ricketsia/Parvo virus serology	X	−
Weil felix reaction	X	−
Urine examination
Urine examination routine	−	−
Urine culture	−	−

−

: negative; +: positive; X: not done; PBS: peripheral blood smear; AFB: acid-fast bacillus; LD: Leishmania Donovan; BMA: bone marrow aspiration; LFT: liver function test; AST: aspartate transaminase; ALT: alanine transaminase; KFT: kidney function test; ESR: erythrocyte sedimentation rate.

Ultrasound and computed tomography scans both confirmed minimal hepatomegaly and mild splenomegaly. In addition, minimal ascites was also seen. Infective endocarditis was ruled out by a two-dimensional echo cardiography.

On histopathological examination, LB showed effaced hepatic lobular architecture with extensive portal inflammation, bridging necrosis and minimal fibrosis. The inflammatory cells comprised of dense lymphocytes, some histiocytes, neutrophils and many plasma cells. The histiocytes showed many intracytoplasmic Leishman Donovan (LD) bodies. Hepatic lobules were largely within normal histological limits. No significant Kupffer cell hyperplasia, plasma cell infiltration nor ballooning degeneration of hepatocytes was seen (Figure 1(a) to (c)). OPEN IN VIEWER

Figure 1.

Liver biopsy from case 1 shows effaced hepatic architecture. There is extensive portal inflammation and bridging necrosis hepatic lobules were largely within normal limits except mild steatosis ((a) – 40× H&E, (b) – 100× H&E). Dense lymphocytes admixed with plasma cells, histiocytes and neutrophils are seen in portal tracts ((b) – 100× H&E). Many histiocytes show LD bodies (arrow) in them ((c) – 400× H&E). Liver biopsy from case 2 shows maintained lobular architecture ((d) – 40× H&E). The hepatocytes shows marked ballooning degeneration. There is marked Kupffer cell hyperplasia along with moderate chronic inflammatory cell infiltrate, rich in plasma cells ((e) – 100× H&E). The Kupffer cells show many LD bodies (arrow head) within them. Focal intracytoplasmic cholestasis is seen ((f) – 400× H&E).

Discussion

Both our cases of VL were negative on BM examination. Both BMA and trephine biopsies were re-examined but did not reveal any organisms. First case was unusual, as he belonged to a non-endemic area and denied history of recent travel. Leishmania serology was not performed earlier as BM turned out to be negative and this diagnosis was not strongly suspected. There was no significant hepatomegaly. LB was performed owing to abnormal liver function tests. In liver biopsy, there was marked bridging necrosis, giving rise to cirrhosis-like appearance. Hepatic lobules were relatively normal without significant Kupffer cell hyperplasia. LD bodies were also restricted to macrophages in the portal tracts. Later, the patient remembered that he had, in fact, travelled to an endemic area eight months previously.

In the second case, however, VL topped the list of differential diagnoses, as he belonged to an endemic area and had typical clinical picture. Both leishmania serology and BM, however, turned out to be negative. LB showed typical picture of leishmaniasis.

Other organisms, which should be excluded morphologically, are histoplasma and toxoplasma.

Morphological changes in the liver in VL involve Kupffer cells, hepatocytes, Ito cells, portal tracts, sinusoids and hepatic veins. Hypertrophy and hyperplasia of the Kupffer cells occur in 44% of cases, and the parasite is generally seen within these cells. Ballooning degeneration of the hepatocytes, bridging (piecemeal) necrosis are usual findings. Inflammatory cellular reaction consists of parasitised macrophages, lymphocytes and plasma cells. They are found in portal tracts as well as in the hepatic lobules (in the sinusoids) either diffusely or focally. ³

Since parasites replicate in the RE system, very high parasite loads accumulate in the spleen, liver and bone marrow. The definitive diagnosis still requires demonstration of the parasite by either histopathology or culture of material obtained by needle aspiration or biopsy from affected organs (usually BM or spleen). In regions where VL is endemic, positive antibody test results may be observed among asymptomatic individuals with subclinical infection.^4,5 Patients with clinical recovery after successful treatment of VL continue to have positive serology for months to years, so these assays cannot be used as short-term tests of cure.^6,7 For these reasons, a positive serological test is not definitive proof of active VL. BMA is a safer but less sensitive method (76%) as compared to splenic aspiration (95%).^8,9 However, splenic aspirate is associated with the risk of fatal haemorrhage in inexperienced hands hence is not routinely performed nor recommended. LB hence is next best option.

The lessons learnt from these two cases are that clinicians should perform LB in suspected cases of leishmaniasis, even if BM turns out to be negative for LD bodies. Travel history to endemic area is important even though not entirely reliable.

Pathologists should be aware of the various morphological pictures of this disease and a high index of suspicion should exist for LD bodies in this treatable disease, which otherwise has very high mortality (90% without and 10% with treatment).

Summary

Two cases of visceral leishmaniasis are presented, where bone marrow examination was negative and showed different morphological pictures in the liver biopsies. It is important for the pathologists to recognise them, to diagnose such cases correctly.