Lymphomatoid granulomatosis: A case series from South India

Context: Lymphomatoid granulomatosis (LYG) is a rare B-lymphoproliferative disorder characterised by an angiocentric and angiodestructive pattern along with Epstein - Barr virus (EBV) association. It is one of the diagnostic challenges in lymphoma pathology. Deregulation of EBV immune surveillance is one of the narrated hypotheses in the literature. Extrapulmonary manifestations are rare with LYG. Morphological grading is done based on the number of EBV-positive B cells, which is useful to strategize treatment protocol. Aims: We report here a series of nine cases of LYG to discuss the clinical, histological, and immunohistochemistry findings. Settings and Design: This is the first case series from India in published literature. Subjects and Methods: We reviewed cases of LYG diagnosed at our center for the past 11 years (2006-2016). A total of nine cases were included in this study. Histomorphology was studied in conjunction with immunohistochemistry and clinical details. Cases without classical morphology and negative for EBV immunostain were excluded from the study. Results: There were nine patients in our study (7 males and 2 female; M:F ratio 3.5:1). The age of these patients ranged from 4 years to 57 years (mean age: 30 years). The most common site involved was the lung (4, 44%), followed by the skin (2, 22%), central nervous system (2, 22%) and lymph node (1, 11%). One patient had primary immunodeficiency. Another patient had undergone renal transplant 11 years before the development of the lesion. Angiocentricity and angioinvasion were appreciated in all nine cases (9/9) with necrosis in four cases (44%) and ill-defined histiocytic aggregates in three cases (33%). The histological features were as follows: Grade 1(4 cases, 44%), Grade 2(2 cases, 22%), and Grade 3(3 cases, 33%). Conclusion: LYG is a rare EBV driven angiodestructive disease with predominantly lung involvement as well as isolated extrapulmonary sites as seen in our study. It is often progressive and ultimately fatal in the absence of appropriate treatment. Grading of the lesion helps to initiate the appropriate treatment of choice