Isolated Lymphangioleiomyomatosis in axillary lymph node: A rare case report with review of literature.

Background: Lymphangioleiomyomatosis (LAM) is a rare low grade metastatic tumour spreading through lymphatic vessels. On histology, it shows proliferation of smooth musclelike or epitheliod tumour cells in the lungs or axial lymphatic system. Extrapulmonary LAM is rare. Case presentation: We report a case of a 23-yearold male who presented with generalised lymphadenopathy and skin lesions since one month. The patient had no history of pulmonary LAM, tuberous sclerosis complex or renal angiomyolipoma. The biopsy from the skin nodule performed outside, was reported as Mycosis fungoides with large cell transformation. The biopsy from the axillary lymph node showed an encapsulated nodal tissue with numerous follicles of varying sizes, both primary and secondary follicles. Some of the follicles showed spindle cell proliferation and increased plasma cells in the germinal centres. Prominence of vasculature is also noted. Subcapsular spindle cell proliferation with areas of myxoid degeneration is also noted. On immunohistochemistry, these spindle cells were positive for S100, SMA, and HMB45 and negative for Pan- CK , MDM2, Melan A, Desmin and Beta catenin. D 240 highlighted the lymphatic channels. The patient was treated with chemotherapy. Conclusion: The diagnosis was challenging in this case, as it is rare pathology, less commonly seen in men, and even more, with a history of skin nodules and no history suggestive of pulmonary LAM or other causes of LAM. With spindle cell proliferation in lymph nodes, LAM should always be had in mind and the appropriate immunohistochemistry will help in arriving at the final diagnosis.