Incidental lymphangioleiomyomatosis in the lymph nodes of gynecologic surgical specimens.

OBJECTIVES: Incidentally discovered lymphangioleiomyomatosis (LAM) in sampled lymph nodes are infrequent but intractable issues for gynecologists. The aims of this study were to elucidate the prevalence of incidental nodal LAM in a consecutive cohort of gynecologic surgical specimens from Japanese patients, to document clinicopathological features of nodal LAM cases, and to investigate the association between the subsequent development of pulmonary LAM and tuberous sclerosis complex (TSC).

STUDY DESIGN: We retrospectively reviewed 1732 consecutive Japanese patients who underwent gynecologic surgery with lymph node sampling in the National Cancer Center Hospital between January 2004 and April 2017. The pathological diagnosis of LAM was performed by pathologists. Clinicopathological data were obtained from patients' electronic medical records.

RESULTS: We found that 0.46% (8/1732) of gynecologic surgical specimens with lymph node sampling showed incidental nodal LAM. The size of the lesions was less than 10 mm, and external iliac and obturator nodes were frequently affected. Although there has been no report of a case of incidental nodal LAM developing pulmonary LAM, we identified the first case of a 36-year-old woman who developed pulmonary LAM 7 years after the diagnosis of incidental nodal LAM. None of the 8 patients had a personal or family history of TSC.

CONCLUSIONS: Our case brings attention to the risk of developing subsequent pulmonary LAM. To date, insufficient long-term follow-up data of young patients have hindered us from drawing a definite conclusion that patients with incidental nodal LAM are not at risk for subsequent pulmonary LAM. Future studies should collect and share long-term follow-up data to elucidate the true risk of developing pulmonary LAM in women with incidental nodal LAM.