Intramammary lymph nodes: A question seeking for an answer or an answer seeking for a question?

Protective fibroblastic niches in secondary lymphoid organs

Fibroblastic reticular cells (FRCs) are specialized fibroblasts of secondary lymphoid organs that provide the structural foundation of the tissue. Moreover, FRCs guide immune cells to dedicated microenvironmental niches where they provide lymphocytes and myeloid cells with homeostatic growth and differentiation factors. Inflammatory processes, including infection with pathogens, induce rapid morphological and functional adaptations that are critical for the priming and regulation of protective immune responses. However, adverse FRC reprogramming can promote immunopathological tissue damage during infection and autoimmune conditions and subvert antitumor immune responses. Here, we review recent findings on molecular pathways that regulate FRC-immune cell crosstalk in specialized niches during the generation of protective immune responses in the course of pathogen encounters. In addition, we discuss how FRCs integrate immune cell-derived signals to ensure protective immunity during infection and how therapies for inflammatory diseases and cancer can be developed through improved understanding of FRC-immune cell interactions.

[Ectopia of mammary tissue]

Ectopic breast tissue may represent the complete breast (accessory breast), glandular tissue without areola or nipple (aberrant breast tissue), or exclusively the nipple (polythelia). Localization is along the embryonic milk ridge extending from the axilla to the vulva. Only rarely, is ectopic tissue found outside of the milk ridge. Most frequently affected are the axilla, the breast itself, and its close neighbourhood. Ectopic breast tissue may rarely give rise to tumours such as fibroadenoma or carcinoma.

A Pictorial Review of Sonography of Intramammary Lymph Nodes: When to Care and What to Do About It

This pictorial essay reviews and illustrates benign and malignant features of intramammary lymph nodes on mammography, ultrasound, and magnetic resonance imaging, including a review of the clinical and the prognostic significance in patients with known breast cancer. This pictorial essay discusses management suggestions for intramammary lymph nodes in patients with breast cancer.