Background There is a diverse aetiology of the cervical adenopathy, the prompt clinic approach being different depending on the distinction between benignant/malignant.

Material and Method Case 1- boy, 5 years old, from rural environment with lateral cervical right adenopathy of 34/15 mm. IgM and IgG Toxoplasma Gondii antibodies are detected, in high level and IgG test of avidity with low index which plead for an acute form of lymphadenitis toxoplasmosis.

Case 2- boy, 17 years old, with lateral cervical adenopathy of 36/22 mm, rough, mobilizable, non-adherent to deep layers, 3 months persistent. Serologically, high levels of titrates of ASLO and high values for IgG VCA CMV which guides initially to an infectious aetiology. The lymph nodes echography highlights the Solbiati index (L/T)=0,87, intranodal calcifications and the absence of the hilar echogenicity and raises the suspicion of malignancy, afterwards confirmed by the biopsy. The final diagnostic is of lymph nodes metastasis of the undifferentiated lymphoepithelial carcinoma.

Case 3- girl, 8 years old, lateral cervical adenopathy of 33/22 mm. In addition, there is a papule at the girl’s neck occurred after 2 weeks since she was scratched by a cat. The high level of Bartonella Henselae titre, the context and the chronology of the lesions – scratch – papule of inoculation, adenopathy guides to Scratch cat disease.

Case 4 – girl, 11 years old, lymph nodes mass of 25/28 mm persistent for 1 year, with local Celsian signs. TB skin test PPD 2U=15 mm Palmer III, the Quantiferon TB test positive. The biopsy culture is positive for BK, guiding the diagnostic to a specific bacillar adenopathy.

Conclusions The complexity of the aetiology of the cervical adenopathy requires the quickest differentiation of the malignant aetiology from the benignant one. The sonography plays an extremely important part in detecting some characters of malignity, and the morpho-patological exam remains the gold standard in diagnosis.