Lymph Nodes in the Groin
The lymph nodes in the groin are called inguinal lymph nodes, which are further subdivided into superficial and deep inguinal nodes. 1
Anatomical Classification
The inguinal lymphatic system consists of two main groups:
Superficial inguinal nodes: These drain the skin of the lower extremities, perineum, and superficial penile structures including the prepuce and shaft skin. 1, 2
Deep inguinal nodes: These are located in the femoral triangle and receive drainage from the glans, deep penile structures, and deeper tissues of the lower extremity. 1, 2
Clinical Nomenclature
While the distinction between superficial and deep inguinal nodes exists anatomically, this differentiation is clinically insignificant because these nodes are difficult to distinguish on physical examination or imaging. 1
Regional Drainage Pattern
The inguinal nodes serve as the primary drainage site before lymph proceeds to the pelvic (iliac) nodes:
Lymphatic flow progresses from inguinal nodes to ipsilateral iliac nodes (obturator, internal iliac, and external iliac). 1
Crossover to contralateral inguinal nodes can occur at the presymphyseal lymphatics before entering the inguinal region, which is clinically important for understanding bilateral disease spread. 3, 2
Anatomical Landmarks
Recent lymphoscintigraphic studies have identified that sentinel lymph nodes most commonly locate in Dassler's superomedial segment of the inguinal region. 1, 3
The superior lateral quadrant of the groin contains the highest concentration of lymph nodes (mean 3.3 nodes), supplied primarily by the superficial circumflex iliac vessels. 4