Unusual presentation of primary cutaneous melanoma of the forearm with epitrochlear and axillary lymphadenopathy

Abstract

In patients with primary cutaneous melanomas of the distal upper limb, metastatic involvement of the epitrochlear lymph nodes is uncommon. It belongs to a particular category of nodal metastasis termed as interval or in-transit lymphadenopathies often encountered by tumour cells as they spread from the primary sites. We describe the case of a 41-year-old woman who presented with a right forearm melanoma that was metastatic to both the epitrochlear and axillary lymph nodes. She underwent wide excision of the primary lesion as well as epitrochlear and axillary nodal clearances in the same sitting. Although uncommon, It is prudent to search for the presence of sentinel lymph nodes in the epitrochlear region although uncommon, and where positive, a completion axillary clearance should be undertaken at the same time as the epitrochlear clearance. Failure to detect the presence of interval lymph nodes along the melanoma spread pathways may be a cause of tumour recurrence.

Imaging Assessment of Interval Metastasis from Melanoma

“…Regarding differential diagnoses, many conditions can be associated with the presence of a nodular image within soft tissues, including normal or abnormal vessels, dense scars, and nodal and extra-nodal diseases [ 34 , 64 , 65 , 66 ]. Nodal causes include acute lymphadenitis (e.g., cat scratch disease), tubercular lymphadenitis, sarcoidosis-related lymphadenitis, lymphomas, and metastatic lymphadenopathies (especially from melanomas, but also from other cutaneous and non-cutaneous cancers) [ 34 , 64 , 65 , 67 ].…”

“…Regarding differential diagnoses, many conditions can be associated with the presence of a nodular image within soft tissues, including normal or abnormal vessels, dense scars, and nodal and extra-nodal diseases [ 34 , 64 , 65 , 66 ]. Nodal causes include acute lymphadenitis (e.g., cat scratch disease), tubercular lymphadenitis, sarcoidosis-related lymphadenitis, lymphomas, and metastatic lymphadenopathies (especially from melanomas, but also from other cutaneous and non-cutaneous cancers) [ 34 , 64 , 65 , 67 ]. Extra-nodal causes include cysts, fluid collections (seromas, hematomas, and lymphoceles), abscesses, tumors (nerve tumors, fibromas, hemangiomas, lipomas, and Merkel cell tumors), cutaneous and subcutaneous hematogenous metastases, and Kimura’s disease [ 22 , 32 , 34 , 64 , 65 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ].…”

“…Nodal causes include acute lymphadenitis (e.g., cat scratch disease), tubercular lymphadenitis, sarcoidosis-related lymphadenitis, lymphomas, and metastatic lymphadenopathies (especially from melanomas, but also from other cutaneous and non-cutaneous cancers) [ 34 , 64 , 65 , 67 ]. Extra-nodal causes include cysts, fluid collections (seromas, hematomas, and lymphoceles), abscesses, tumors (nerve tumors, fibromas, hemangiomas, lipomas, and Merkel cell tumors), cutaneous and subcutaneous hematogenous metastases, and Kimura’s disease [ 22 , 32 , 34 , 64 , 65 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ].…”

“…The origin is typically hilar in benign lymph nodes, with monopolar vascularity; in malignant lymph nodes, multiple vessels can penetrate the lymph node through the capsule [ 32 , 33 , 34 ].…”

“…Therefore, the combination of US findings, such as round or oval morphology, markedly hypoechoic structure, focal or nodular and asymmetric cortical thickening, and hilum loss or dislocation with anarchic distribution of the vascular signal, regardless of size, is virtually diagnostic of metastasis [ 14 , 28 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ].…”