Immunoglobulin heavy and light chains and T-cell receptor beta and gamma chains PCR assessment on cytological samples. A study comparing FTA cards and cryopreserved lymph node fine-needle cytology.

OBJECTIVES: To evaluate and compare the DNA yield and quality extracted from lymph node fine needle cytology (FNC) samples stored on FTA cards to those cryopreserved, and to assess the immunoglobulin heavy and light chains (IGHK) and T-Cell receptor beta and gamma chains (TCRBG) PCR tests. METHODS: DNA extractions were performed on FNC of 80 non-Hodgkin lymphomas (NHL), four myelomas and 56 benign reactive hyperplasias (BRH) cryopreserved and stored on FTA cards. The JAK2 gene was amplified to assess the DNA integrity and the IGHK/TCRBG clonality status was tested. RESULTS: IGHK monoclonality was found in 99% of B-cell NHL and 100% of myeloma. TCRBG monoclonality was found in 100% of T-cell NHL. TCRBG polyclonality was detected in 97% of B-cell NHL, 100% of myeloma and 96% of BRH. IGHK/TCRBG PCR data were confirmed by histological and/or follow-up controls. No differences were found in the DNA quality between cryopreservation and FTA cards storage methods. CONCLUSIONS: IGHK/TCRBG PCR of the lymphoproliferative process on FTA cards is comparable to those cryopreserved. FTA cards can be used to store lymph node FNC for further molecular investigations.

Fine needle aspiration cytology of lymphoproliferative lesions of the oral cavity.

OBJECTIVE: Oral cavity non-Hodgkin lymphoma (OCL) is a rare condition that may be clinically and radiologically indistinguishable from other pathologies of the mouth. A complete excision or adequate biopsy of the OCL may be difficult. Fine needle aspiration (FNA) cytology has been successfully utilized in the pre-operative diagnosis of oral masses and in lymphoma involving other anatomical areas. Our experience with FNA pre-operative cytological diagnosis of 16 OCLs is reported herein. METHODS: The results of FNA cytology on 16 consecutive lymphoproliferative lesions of the oral cavity collected over an 8-year period in three institutions were retrieved. Sampled lesions were submucosal masses of different sizes bulging into the oral cavity. Rapid on-site evaluation (ROSE) and routine cytological staining were performed. Immunocytochemistry (ICC), flow cytometry (FC) and polymerase chain reaction (PCR) of the IGH (immunoglobulin heavy) locus were performed on additional passes according to ROSE. RESULTS: Fourteen OCLs, one myeloma and one florid reactive lymphoid hyperplasia (FRLH) were diagnosed by FNA. OCLs were diagnosed as large B-cell (eight cases) and small B-cell (six cases) lymphomas. Histology revealed eight diffuse large B-cell lymphomas (DLBCL), four lymphomas of mucosa-associated lymphoid tissue (MALT), two follicular lymphomas and one FRLH; no false-negative or false-positive results were diagnosed, but accurate subclassification was obtained in four cases only. CONCLUSIONS: FNA diagnosis of OCLs may be hampered by the rare incidence, anatomical context and difficulties in obtaining a sufficient amount of cells. Ancillary techniques should be used according to ROSE; a pre-operative FNA cytology diagnosis can avoid unnecessary extensive surgery and speed up the institution of therapeutic procedures.