Objective:Rare disease Background:Pseudolymphoma is a rare disorder that can mimic lymphoma both clinically and histologically. It usually affects middle-aged females. Since pseudolymphoma is a rare disorder not only is diagnosing the condition difficult, but there is also a lack of standardized treatment guidelines. In the literature, anti-CD20 monoclonal antibody rituximab is described as an effective treatment option. Case Report:46-year-old female fell ill suddenly with swelling and enlargement of her chin. Multiple skin biopsies were done, which were re-evaluated multiple times as well. Each ended with a new diagnosis for the patient. Finally, in the last revision of biopsy material, pseudolymphoma was confirmed. The patient received multiple courses of corticosteroid treatments -locally and systemically -without long lasting effect. After diagnosis of pseudolymphoma, the patient was started on intravenous rituximab and this treatment was effective. Conclusions:Cutaneous pseudolymphoma is a diagnostic challenge. Rituximab is a treatment option for refractory pseudolymphoma. Since there are no treatment guidelines for pseudolymphoma, more clinical studies are needed to establish best treatment options for these patients. Therefore, each reported clinical case is important.

Summary. Progressive multifocal leukoencephalopathy (PML) is a rare and often fatal demyelinating disease of the central nervous system caused by John Cunningham virus (JCV). We present a case report of patient with non-Hodgkin follicular lymphoma, who developed PML after hematopoietic stem cell transplantation and rituximab-bendamustine therapy. JCV DNA was proven both in peripheral blood and cerebrospinal fluid. Patient with 4 years history of follicular lymphoma presented with progressing weakness in the right arm and leg and postural instability. Magnetic resonance imaging scans showed bilateral hyperintense lesions in the cerebellum and centrum semiovale consistent with findings in PML. JCV DNA was detected in patient peripheral blood and cerebrospinal fluid by real time polymerase chain reaction assay in CERBA laboratory (France). Human herpes simplex 6 and 7 DNA were also detected in peripheral blood by PCR. Patients condition rapidly deteriorated with exitus letalis after 3 months and 2 weeks from onset of symptoms. This case draws attention to risk for developing PML in patients with long-standing hematological malignancies.