Anaplastic Large Cell Lymphoma Mimicking a Necrotizing Granulomatous Lesion: A Case Report

Introduction

Epithelioid cell granulomas into neoplastic tissues have been reported in association with a wide series of neoplasms, including lymphomas. Between lymphomas, Hodgkin’s lymphoma and T-cell derived non Hodgkin lymphoma are more seen commonly [1]. The presence of non-necrotic epithelioid cell granulomas is well known findings in lymph nodes, spleen, bone marrow, and liver from patients with Hodgkin’s disease [2, 3, 4]. Epithelioid granulomas in association with non-Hodgkin’s lymphomas are only rarely observed [5, 6]. When granulomas are present in association with lymphomas, they are usually non necrotizing, sarcoid-like [7, 8, 9]. Nevertheless, rarely necrotizing granulomas occurs. Hall et al. reported two cases of high-grade malignant lymphoma characterized by extensive necrosis in association with granulomatous reaction mimicking tuberculosis [10, 11]. Chow et al. reported three cases of lymphomas masquerading as granulomatous panniculitis from inflammatory or reactive disorders associated [12]. In these cases an infectious cause is not found and their development has been attributed to an immune or inflammatory reaction to tumour-associated antigens, probably [13, 14, 15]. Little is known about the association of granulomatous reaction with anaplastic large cell lymphoma and to the best of our knowledge anaplastic large-cell lymphoma with histological features of necrotizing granulomatous lesion has not been reported previously in the literature. In this article we report a case of anaplastic large-cell lymphoma mimicking a necrotizing granulomatous lymphadenitis.

Case Presentation Section

Case Report: a 55-year-old Caucasian man in otherwise good health, presented with a 3-month history of a

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The T-cell clonality assay employs primers for both TCRB and TCRG, a combination that has been shown to detect clonality in essentially 100% of T-cell prolymphocytic leukemias, T-cell large granular lymphocyte disorders, and peripheral T-cell lymphomas, unspecified, with somewhat lower rates reported in angioimmunoblastic T-cell lymphomas and anaplastic large cell lymphoma [16, 17]. Commercial reagents by ROCHE VENTANA, Italy were used to perform immuno-hystochemical assay and by EXPERTEAM (Marghera Venezia, Italy) and INVIVOSCRIBE TECHNOLOGIES (San Diego, California USA) were used to perform beta-globin and clonality T assay, respectively. All used products are compliant to the requirements of the in vitro diagnostic directive (IVDD) 98/79/EC.

Discussion

The majority of cancer diagnoses are made on the basis of either histologic or cytologic evaluation. Generally, the error frequency and effect are poorly characterized because there is no uniform measurement process, but, in this case, the current guide lines and the appropriated procedures have been respected. Here, we report a case of primary nodal anaplastic large-cell lymphoma mimicking a necrotizing granulomatous lymphadenitis. Rarely, the diagnosis of a lymphoma may be masked by the presence of extensive granulomatous lesions. Lymphomas associated with marked granulomatous reaction are well documented in the literature [8]. Malignant lymphomas and solid tumours that mimic or are associated with epithelioid granulomas are a dilemma in histological materials. Granulomatous lymphadenitis may be determined by several infective agents or determined by different pathological processes, sarcoidosis and tuberculosis being the most frequent. Granulomatous lymphadenitis may also occur along haematological diseases or after chemotherapy or radiotherapy. Granulomatous reaction after chemotherapy for Hodgkin’s disease has been described in the literature [14]. A prognostic relevance of the granulomatous reaction in ALCL lymphoma is not clear. Little is known about the association of granulomatous reaction with anaplastic large cell lymphoma (ALCL) [18]. The differential diagnosis of necrotizing granulomas includes chronic infections such as typical and atypical mycobacterium, fungi (e.g., histoplasmosis, aspergillosis, cryptococcosis), and Wegener’s granulomatosis, as well as foreign body type granulomatous inflammations [18]. In our case an infectious cause is not found and granuloma development could be attribute to an immune or inflammatory reaction to tumor-associated antigens [1, 13]. This case emphasizes the importance of a very careful microscopic evaluation of the lymph nodes with non- necrotizing granuloma searching for any large atypical cells that may represent hidden malignant cells that can be easily overlooked. In addition, the massive necrosis found here, could call in question the veracity of the immunohistochemical and molecular assays. Many authors reported cases of lymphomas with complete lymph node necrosis in which immunophenotypic and immunogenotypic studies were performed successfully [19, 20]. After the diagnosis, the patient underwent to oncology visit in a different hospital, so it was not possible to know the stage of lymphoma or the appropriated therapeutic treatment. Although, it should be very interesting, here we want principally to focus attention on the histological diagnosis. We describe a case of an unusual ALCL lymphoma that was associated with exuberant granulomatous reaction and has been misdiagnosed as necrotizing granulomatous lymphadenitis.

Conclusion

The purpose of this article is to provide a strong suggestion for pathologists. In fact, the aim of this case report is to emphasize the importance of an extensive immunophenotypic characterization, in conjunction with histomorphologic and molecular analysis in all instances of the lymph nodes with granulomatous reaction. This case highlights the importance of a careful assessment of any necrosis in lymph node, using a multimodality diagnostic approach to distinguish lymphomas masquerading as granulomatous lesion from inflammatory or reactive disorders associated with such histopathologic patterns, specially, when the diagnosis should be wrong and the treatment cannot be delayed and/or imprecise.