Diagnostic application of Epstein-Barr virus-encoded RNA in situ hybridisation.

AIMS: Epstein-Barr virus (EBV) has been implicated in the pathogenesis of nasopharyngeal carcinoma and a range of proliferative lymphoid conditions. In situ hybridisation (ISH) looking for virus-encoded RNA (EBER) transcripts is performed simply using a commercially available probe. We aimed to examine the application of this test in a routine diagnostic setting. METHODS: In total, 26 cases in which EBV ISH was requested for diagnostic purposes were examined. We looked at the indication for testing, the result and its implication for the final diagnosis. RESULTS: Cases were classified into three categories: possible nasopharyngeal carcinoma; possible EBV-related lymphoma; and possible immunodeficiency-associated lymphoproliferative disorder. Six of nine cases of possible nasopharyngeal carcinoma were EBV ISH positive (3/3 primary and 3/6 secondary), confirming the diagnosis. Three of 14 possible lymphoma cases were EBV ISH positive which, along with appropriate ancillary tests, assisted in making the diagnoses of Burkitt's lymphoma, lymphomatoid granulomatosis and extranodal NK/T-cell lymphoma of nasal type. All of three immunodeficiency-associated cases were EBV ISH positive. Two of these were post-transplant lymphoproliferative disorders, monomorphic type. The third case was classified as HIV-related polymorphic lymphoproliferative disorder. CONCLUSIONS: In our experience, EBV ISH is a straightforward and rapid procedure to perform, giving unequivocal results. Used in the appropriate clinicopathological setting it can be a highly useful ancillary diagnostic aid.

Cutaneous lymphomas: which pathological classification?

Cutaneous lymphomas are rare and although some are a manifestation of systemic lymphoma, the majority arise primarily from the skin. These primary cutaneous lymphomas comprise predominantly T cell subtypes and represent a wide spectrum of disorders. Pathologists can currently choose to label these conditions according to three classifications (REAL, EORTC or WHO) but each has shortcomings. Nonetheless, in an attempt to unify the field, we would recommend that pathologists make every attempt to categorise these conditions according to the WHO classification. This classification can encompass all the conditions and aligns the cutaneous lymphomas with the broader systemic lymphoproliferative conditions.

Clinical study of primary cutaneous B-cell lymphoma using both the European Organization for Research and Treatment of Cancer and World Health Organization classifications.

Primary cutaneous B-cell lymphoma (PCBCL) is rare, with few series reported in the literature. Its classification and treatment remain controversial. Biopsy specimens of 13 patients with PCBCL were classified according to both the European Organization for Research and Treatment of Cancer (EORTC) and the new World Health Organization (WHO) classifications. Treatment and clinical outcomes were documented. Using the EORTC classification there were seven men and six women aged 32-85 years (mean = 51 years) with follicle centre cell (FCC) lymphoma (nine), immunocytoma (two) and primary cutaneous large B-cell lymphoma of the leg (PCLBCL-leg) (two). When the WHO classification was used, the nine patients with FCC were reclassified as follicle centre (five) and diffuse large B-cell lymphoma (four). Most patients had localized disease (12). Initial treatment consisted of radiotherapy alone (seven), combination chemotherapy alone (one), combined chemoradiotherapy (three) and surgery (two). Twelve patients achieved complete remission (median follow up 28 months, range 10-167 months). One patient with PCLBCL-leg died from progressive cutaneous disease. Most localized PCBCL lesions (except PCLBCL-leg) have a favourable prognosis. We recommend that clinicians be familiar with the important differences in the EORTC and WHO classifications. Further large prospective studies comparing the WHO and EORTC classifications are required to more clearly delineate the outcomes of the increasing number of patients who are classified as DLBCL by the WHO system.