What parasitic infections, aside from Echinococcus, can mimic clear cell renal carcinoma in a pediatric patient?

Parasitic Infections Mimicking Clear Cell Renal Carcinoma

Malaria, particularly Plasmodium malariae and Plasmodium falciparum, can mimic clear cell renal carcinoma through renal parenchymal involvement and cystic changes, though this mimicry is primarily clinical and radiographic rather than histopathologic.

Primary Parasitic Differential: Malaria

The most clinically relevant parasitic infection that can present diagnostic confusion with renal masses is malaria:

Plasmodium malariae

• Creates chronic renal parenchymal changes including membranoproliferative glomerulonephritis and chronic tubular/interstitial nephritis that can appear as mass-like lesions on imaging 1
• Particularly affects pediatric patients, with nephrotic syndrome occurring in approximately 0.47% of children under 5 years with P. malariae infection 2
• Causes significant renal structural changes that persist chronically and can mimic neoplastic processes on cross-sectional imaging 1

Plasmodium falciparum

• Produces acute tubular necrosis with vascular obstruction by parasitized erythrocytes, creating focal renal lesions that may appear mass-like 3, 4
• Triggers post-infectious acute glomerulonephritis with inflammatory changes that can simulate malignancy radiographically 1
• Causes acute kidney injury through impediments in renal microcirculation and infection-triggered proinflammatory reactions within the kidney parenchyma 4

Other Parasitic Considerations

Schistosomiasis

• Schistosoma haematobium causes chronic tubular and interstitial nephritis with progressive renal function deterioration, creating mass-like inflammatory changes 1
• Schistosoma mansoni leads to mesangial and membranoproliferative glomerulonephritis that can appear as focal renal abnormalities 1

Leishmaniasis

• Produces acute glomerulonephritis, nephrotic syndrome, or acute interstitial nephritis that may present as focal renal lesions on imaging 1
• Generally causes mild renal involvement but can create more serious manifestations mimicking neoplastic processes 1

Critical Diagnostic Distinctions

The key differentiating factor is travel history and endemic exposure - any pediatric patient with a renal mass and travel to malaria-endemic regions (sub-Saharan Africa, Southeast Asia, India) requires parasitic workup before assuming malignancy 3, 2, 4.

Clinical Red Flags for Parasitic Etiology:

• Fever preceding renal findings by days to weeks 3
• Severe anemia disproportionate to renal mass size (mean hemoglobin 9.0 g/dL with P. malariae) 2
• Nephrotic syndrome in young children with renal abnormalities 2
• Acute kidney injury with oliguria in the setting of recent fever 3, 4

Diagnostic Workup Priority:

• Thick and thin blood smears for Plasmodium species identification before proceeding to biopsy 3, 2
• Urinalysis for proteinuria and hematuria suggesting glomerulonephritis rather than neoplasia 1
• Renal biopsy when available to distinguish inflammatory/infectious changes from clear cell carcinoma histology 3

Important Caveats

The mimicry is predominantly radiographic and clinical rather than histopathologic - true histologic confusion between parasitic renal disease and clear cell RCC is rare, as the characteristic clear cytoplasm and VHL pathway alterations of clear cell RCC are absent in parasitic infections 5.

In pediatric populations, always consider hereditary RCC syndromes (FH-deficient RCC, SDH-deficient RCC) alongside parasitic etiologies, particularly in younger patients with difficult-to-classify renal masses 5.

Renal hydatid cysts from Echinococcus remain the classic parasitic mimic (as noted in the question), diagnosed in 2-3% of hydatid disease cases, with surgery as the only definitive treatment 1.