A 2-MONTH-OLD male infant presented with fever, which he had since age 1 month, and recurrent generalized seizures. On physical examination, jaundice, low-set ears, and a flattened nasal bridge were seen. The liver (4 cm below the right costal margin) and spleen (9 cm below the right costal margin) were palpable below the respective costal margins. Punched out ulcers in the perianal region were also seen. He was third in the birth order, with 2 older siblings who are still alive and healthy. There was no family history of consanguinity. Investigations revealed pancytopenia, a hemoglobin level of 40 g/L; a platelet count of 10 × 109/L; total leukocyte count of 0.0027 × 109/L, with 0.16 polymorphonuclear leukocytes, 0.78 lymphocytes, 0.04 myelocytes, and 0.2 monocytes; a prothrombin time of 25 seconds (control, 14 seconds), and a prothrombin thromboplastin time with a kaolin level 120 seconds (control, 35 seconds). There was hypofibrinogenemia (120 mg/L) with increased levels of serum bilirubin (131.67 µmol/L [7.7 mg/dL]) and alkaline phosphatase (27 King-Armstrong units). A Venereal Disease Research Laboratory test was nonreactive; toxoplasma and herpes simplex virus titers and human immunodeficiency virus and urine tests for CMV were negative. Computed tomographic scan of the head revealed a mild hydrocephalous with periventricular lucencies.
The brain weighed 505 g and exhibited mild hydrocephalus, periventricular sclerosis, and focal softening. The central white matter was focally soft with degeneration and fissuring (Figure 1). Microscopically, meningeal infiltration by lymphohistiocytes was seen (Figure 2). There was widespread periventricular and intraparencymal (gray and white matter) perivascular lymphohistiocytic infiltration mimicking an encephalitic process (Figure 3). The brain between the perivascular infiltration showed astrocytic proliferation admixed with diffusely infiltrating as well as nodular histiocyte aggregates (Figure 4). Similar perivascular infiltration was observed in the thalamus, globus pallidus, midbrain, and pons. The liver and spleen were enlarged (Figure 5). There was a heavy benign lymphohistiocytic infiltrate in the liver sinusoids (Figure 6), spleen, red pulp, bone marrow, lymph nodes, skin, adrenal glands, pancreas, intestines, kidneys, and perianal area. The infiltrate revealed prominent erythrophagocytosis.
Vasishta RK, Kakkar N, Banerjee AK, Marwaha RK. Pathological Case of the Month. Arch Pediatr Adolesc Med. 1999;153(5):545-546. doi: