Utility of 18F-fluorodeoxyglucose PET-CT scan in detecting bone marrow involvement in lymphoma.

Background & objectives: Evaluation of bone marrow infiltration in lymphoma is usually done by bone marrow biopsy (BMB). This study analyzed the utility of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography (18F-FDG PET/CT) to detect bone marrow involvement (BMI) compared to BMB. Methods: Treatment-naïve lymphoma patients underwent both 18F-FDG PET/CT scan and BMB before treatment initiation. BMI detected on PET/CT was compared with BMB. Results: The study population consisted of 80 patients and comprised 37 Hodgkin's lymphoma (HL) patients, 30 aggressive non-HL (NHL) and 13 indolent NHL patients. The majority of the aggressive NHLs were diffuse large B-cell lymphoma (20/30) and major indolent lymphoma was follicular lymphoma (5/13). When compared to BMB, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of focal (±diffuse) marrow FDG uptake on 18F-FDG PET/CT were 100, 61.3, 33.3 and 100 per cent, respectively, for HL; 100, 65.4, 30.8 and 100 per cent, respectively, for aggressive NHL and 75, 80, 85.7 and 66.7 per cent, respectively, for indolent NHL. When comparing marrow involvement on 18F-FDG PET/CT to baseline BMB and/or resolution of bone marrow FDG uptake at interim/end-of-treatment 18F-FDG PET/CT, the sensitivity, specificity, PPV and NPV were 100 per cent each for HL and aggressive NHL and 77.3, 100, 100 and 66.7 per cent, respectively, for indolent NHL. Interpretation & conclusions: 18F-FDG PET/CT has a good sensitivity and NPV for detecting BMI in HL and aggressive lymphoma. The low specificity and PPV improved if marrow uptake pattern on interim or end-of-treatment 18F-FDG PET/CT scan was analyzed. In patients with HL who are staged with18F-FDG PET/CT at baseline and followed up with an interim/end-of-treatment PET/CT, baseline BMB may be avoided. For all other lymphoma subtypes, BMB may be essential if there is no marrow FDG uptake on PET/CT scan performed at baseline.

JAK2 exon 12 mutations in cases with JAK2V617F-negative polycythemia vera and primary myelofibrosis.

Molecular detection of JAK2 mutation (V617F or exon 12) is included as a major diagnostic criterion for polycythemia vera (PV) by the WHO 2016 guidelines. JAK2 exon 12 mutations are seen in about 2-5% of JAK2V617F-negative cases of PV. Mutations in JAK2 cause constitutive activation of JAK-STAT pathway which results in variable phenotypes. PV patients with exon 12 mutations in JAK2 present characteristically with erythrocytosis. There are limited reports describing the spectrum of JAK2 exon12 mutations in myeloproliferative neoplasms (MPNs). Here, we describe the characteristics of a series of MPN patients with mutations in exon 12 of JAK2 of which two were novel variants associated with polycythemia. Interestingly, we noted two patients presenting as myelofibrosis having JAK2 exon 12 mutations.

Brush Cytology and AgNOR in the Diagnosis of Oral Squamous Cell Carcinoma.

OBJECTIVE: We aimed to evaluate the role of brush cytology in the screening of oral lesions with malignant suspicion and compare it with histopathology in north-eastern India. STUDY DESIGN: Brush cytology samples taken from 48 patients were processed for conventional cytology (CC) and liquid-based cytology (LBC), and biopsy samples were also obtained. LBC samples were also stained to assess the argyrophilic nucleolar organizer region (AgNOR). The cytology was compared with histopathology, both individually and in combination with AgNOR. The smear quality was compared with histopathology for evaluating their diagnostic accuracy. RESULTS: The sensitivity of diagnosing oral cavity squamous cell carcinoma by LBC and CC alone was 75 and 85%, respectively, which improved on combining with the AgNOR count, with a cutoff of 6.5. The presence of round cells on cytology was significantly associated with high-grade lesions. LBC provided clearer cytomorphology but compromised the background information in high-grade lesions. CONCLUSION: Brush cytology is a minimally invasive tool for screening oral lesions with malignant suspicion. LBC and CC are complementary techniques for cytological screening and combining them with AgNOR can increase the diagnostic yield. With objective criteria for assessment, cytology can be an indispensable tool for screening oral lesions in a resource-limited set-up, especially in high-incidence regions.

Natural Killer Cell Lymphoma: A Case with Classification Dilemma.

Non-Hodgkins lymphoma of the Natural Killer (NK) cell type is rare. World Health Organisation recognises 3 NK-cell phenotypic entities; extranodal NK/T cell lymphoma, nasal type (ENK/TL); aggressive NK cell leukaemia (ANKL); and chronic lymphoproliferative disorders of NK cells (CLPD-NK) which is classified as a provisional entity. Though specific clinical, morphological and immunophenotypic criteria have been laid down to diagnose these conditions there may however, be considerable variations in the clinical presentation making diagnosis difficult. We present a case with contrasting clinical and haematopathological findings posing difficulty in its diagnosis and classification, and despite the aggressive presentation showing favourable response to treatment.