[Rosai-Dorfman lymphadenopathy, a rare reactive lymphoproliferative disease. How valid are ultrasound morphologic criteria in lymph node involvement?].

AIM: The established criteria for benignity or malignancy of lymph nodes when evaluated with B-mode ultrasound can be divided into quantitative measures (size, quantity, contour and density) and qualitative parameters (configuration and structure). The validity of these criteria is controversial. METHODS: Two cases of sinus histiocytosis with massive lymphadenopathy (SHML) are presented; this is a rare benign reactive disorder in which massive enlargement of cervical lymph nodes often occurs. These enlarged nodes offer a chance to demonstrate and discuss the validity of the sonomorphological criteria. RESULTS: The enlarged lymph nodes in SHML fulfill most of the criteria for malignancy. The same results are meet in other disorders with prominent but benign lymphadenopathy. CONCLUSION: The current ultrasonic criteria to determine benignity/malignancy in lymph nodes most likely simply indicate a large number of enlarged nodes. Pathologic diagnosis remains the gold standard.