BREAST CYTOPATHOLOGY

Hematologic Tumors: Malignant Lymphoma
and Plasma Cell Tumors
Clinical Features
• Malignant lymphomas of the breast, both primary and
secondary, are extremely rare and may appear at any age.
• Patient may have multiple lesions, with up to 10% of
patients presenting with bilateral disease.
• The clinical presentation may mimic primary breast
carcinomas.
• Most often, primary and secondary lymphomas or plasma
cell tumors may appear as well-circumscribed lesions of
varying sizes.
• Lymphoma including Hodgkin lymphoma of the breast is
commonly seen as a manifestation of a known generalized
lymphoma and presents no difficulty in rendering a
diagnosis.
• However, rarely they may occur as a primary breast
cancer, with the majority of them being diffuse large B cell
lymphomas.
• Immunophenotyping with immunocytochemistry or flow
cytometry can establish the diagnosis.
• Axillary node involvement is seen in more than one third
of the patients with lymphoma.
• Plasmacytomas of the breast are rare and generally present
as circumscribed masses that appear solid by imaging.
Cytomorphologic Characteristics
(Figures 5.1 to 5.5)
• Characteristics depend on the type of hematologic cancer;
compare with a sample from a known primary.
• Reed-Sternberg cells are diagnostic of Hodgkin disease.
Pitfalls and Differential Diagnosis
• Consider neuroendocrine carcinoma.
• Consider invasive lobular carcinoma.
Hematologic Tumors 139