Presentation
A 70 years old woman presented a palpable lump in the upper outer quadrant of her left breast; she was treated for a left lung adenocarcinoma by surgery alone, four years before (Stage pT1b pN0 M0).
Patient Data
Mammography showed a round, 1.5 cm, well circumscribed nodule, with homogeneous density, tiny lobulated borders, and without microcalcifications or spiculations.
Breast ultrasound
Ultrasound showed a 1,5 cm, hypoechoic, well-limited lesion.
The lesion is so significantly hypoechoic that it can be mistaken for simple cyst.
Eco-color-doppler did not detect vascularization within the nodule.
Case Discussion
The working diagnosis was a breast benign nodule or a solitary metastasis from the previously treated lung cancer.
An ultrasound-guided fine needle aspiration cytology (FNAC) revealed atypical cells (C3).
Core biopsy was not performed and the patient underwent surgery (wide local excision).
The final diagnosis was a primary non-Hodgkin lymphoma, follicular B-cell type, arising from an intramammary lymph node.
The lymph node was enlarged by neoplastic lymphocytic growth that microscopically spread outside the lymph node capsule. The grade was G1. The surgical margins were uninvolved.
This case must not be considered a primary lymphoma of the breast, but a true non-Hodgkin lymphoma arising from an intramammary lymph node.
The development of a lymphoma within an intramammary lymph node is extremely rare since the incidence of lymph nodes within the breast in mammographic series is about 5%.
Only 3 cases are reported in the literature.