Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease due to a lytic infection of oligodendrocytes caused by polyoma virus (JC virus) infection. PML usually occurs in a setting of severe immunosuppression and is most commonly associated with human immunodeficiency virus (HIV) infection. Idiopathic CD4 + lymphocytopenia is a very rare cause of PML and only a few cases have been reported in the literature. We present a case of a 45-year-old man who presented with behavioral alteration followed by progressive weakness of right side of the body. Contrast-enhanced magnetic resonance imaging of the brain revealed confluent irregular areas of T2-weighted/fluid-attenuated inversion recovery hyperintensities in left frontoparietal and right temporoparietal regions. His hematological work up showed a decreased absolute CD4 + count of 217 per microliter, but was negative for HIV serology. Keeping a differential diagnoses of central nervous system lymphoma, brain biopsy was performed. Histopathology revealed demyelination with presence of intranuclear inclusions in the oligodendrocytes, which were positive for SV40 immunostain. Adjacent areas showed reactive gliosis with hypertrophic astrocytes, hence a diagnosis of PML was made. The patient died due to aspiration pneumonia. PML can occur very rarely in association with idiopathic CD4 + lymphocytopenia in the absence of other immunosuppressive illnesses. This report highlights the importance of high index of clinical suspicion and need for a careful histological examination for diagnosis of PML to facilitate adequate patient management.

IntroductionHydatid disease (HD) is caused by the tapeworm of the genus Echinococcus. Fine‐needle aspiration cytology (FNAC) is an expedient diagnostic technique that may be used for its rapid diagnosis.AimTo study the clinical and cytomorphological spectrum of HD diagnosed by cytology.Material and methodsA total of 24 patients diagnosed with HD on FNAC and fluid were studied over a period of 5.5 years. May Grunwald Giemsa, Periodic acid Schiff, and Haematoxylin and Eosin stained smears were studied and analysed for the cytomorphological spectrum of HD.ResultsAmongst the 24 patients studied, the mean age was 29.8 years (range 6‐64 years). There was equal sex preponderance with 12 males and 12 females. The most common organ involved was lung (54.1% of cases) followed by liver (25% of cases). Presence of laminated membranes (n‐20, 83.3%) followed by presence of hooklets (n‐13, 54.1%) were the common cytological features. Scolices and protoscolices representing endocyst were seen in 37.5% of cases (n‐9).ConclusionClinicians and pathologists should be aware of the clinical and morphological spectrum of HD respectively for immediate diagnosis followed by prompt management.