Metastatic lymph nodes in a patient affected by melanoma
Patient with a brownish, raised spot of the upper back (1,3x1,2cm) showing a nodular, not homogenous morphology and irregular margins; the lesion was surrounded by pigmented nodules miming angiomas, with a maximum diameter of 0,5 cm and located 1,5 cm far from the main lesion (Figure-1). The lesion pattern oriented for melanoma with loco-regional satellitosis and the spot and surrounding skin and derma were thus surgically removed. Microscopic examination confirmed the presence of a not ulcerated melanoma with superficial involvement and neoplastic satellitosis. One month after surgery, the patient underwent US examination (high frequency probe/10-13MHZ) of the axillary and inguinal regions; in the left axilla, US revealed an increased lymph node (18x10 mm), which superior pole resulted completely altered, appearing as a hypoechoic area with lobulated margins, suspected for metastatic infiltration of the node; Power-Doppler showed moreover an anarchic distribution of the vessels (Figure-2). Near the first node, US showed also a second node (16x5mm) with a locally thick cortical, suspected for focal metastatic nodularity (3x2 mm) (Figure-3). . To depict any other metastatic nodal involvement, the patient underwent a whole-body PET-CT with 18-FDG, that evidenced only a pathological uptake in the left axillary region (SUV=3,8) (Figure-4). A radical lymphadenectomy of the left axillary region was performed; the pathology confirmed the presence of the two suspected metastatic lymph nodes, of which the biggest resulted to be completely infiltrated while the other showed infiltration of a limited area of the cortical, as it had been suspected at US (Figure-5).
Typical therapeutic approach in case of suspected melanoma consists in spot ablation; if pathological exam confirms the presence of tumor, therapeutic strategy includes the enlargement of the previous surgical field (removing the surrounding skin and subcutaneous tissue) and the examination of the sentinel lymph node. The study of the sentinel node starts injecting a specific radio-drug (generally Tc99m bound to colloid) in the region of pathological spot: some time after it is possible to detect the first drainage node of the lesion area (so called sentinel lymph node), which is surgically removed and analyzed by the pathologist. If histological analysis excludes neoplastic nodal infiltration, metastatic spreading is usually considered very unlikely, while if the sentinel node results infiltrated, all nodes of the same chain are removed (radical lymphadenectomy). In our case, the patient underwent US examination of axillary and inguinal regions instead of the lymphscintigrapy, because these superficial regions, frequent site of metastatic nodal involvement in cases of melanoma of the back, can be accurately evaluated also by imaging; US examination was anyway completed by PET-CT. Imaging role in patients affected by melanoma consists mainly in neoplasm staging, and depicting nodal and/or distant metastatic localizations. High frequency US allows in fact an accurate evaluation of the node structure. Typical US characteristics of a normal node are: -oval morphology, with a short/long axis rate >2; -thin but well defined cortical; -well defined hilum; -vessels mainly distributed at hilum (evaluated at Power-Doppler). The pattern of a metastatic node includes, instead, these imaging characteristics: -round morphology, with a short/long axis rate<2; -irregular margins with thickness of the cortical and possible eccentric, inhomogeneous areas; -frequent hilum lack or dislocation due to neoplastic infiltration; -aberrant vessels (passing through the cortical, with an irregular calibre and final stop at Power-Doppler). CT instead, does not represent a sensitive method to detect metastatic nodes, while the unique criterion that can lead to the suspicion of a metastatic lymph node is nodal enlargement (short axis measuring > 1cm). The possibility of acquiring very thin CT slices (<1mm) and create multiplanar reconstructions allows anyway to determine all nodal diameters and so to express an evaluation of nodal malignancy basing on the shape roundness. Nevertheless, in case of a not dimensionally significant lymph node at CT, it is not anyway possible to exclude certainly microscopic metastatic foci. Lately, also MR has been introduced in analyzing lymph nodes, because of its ability in depicting melanin, usually concentrated in normal and metastatic nodal cortical. Melanin determines a T1 time shortness, with a consequent hyperintensity in T1 weighted images, while signal intensity in T2 w.i can be quite variable, resulting mostly hypointense, because of the concomitant shortening of T2 time. Moreover, the use of superparamagnetic contrast medium (iron ioxides particles) has resulted useful in differentiating hyperplastic from metastatic nodes: reactive nodes appear in fact hypointense in T2 w.i. after contrast medium administration, while metastatic nodes show hyperintense because of the lack of ioxides particles captation by the lymphcites.
Two-Metastatic axillary lymph nodes in a patient affected by melanoma
1. Skin lesion (at the site of the back melanoma): The lesion appears dark in color with an irregular raised surface, and pigmented or nodular changes can be observed in the surrounding area. Combined with the patient’s previous history, this strongly suggests a high-grade malignancy.
2. Ultrasound examination (axillary and inguinal lymph nodes): Some lymph nodes appear round, with a significantly thickened cortex and uneven internal echo distribution; the hilum structure is unclear or deviated. Doppler imaging shows abnormal blood flow patterns, disordered intracortical vessels, and increased blood flow, suggesting possible malignant metastasis.
3. CT scan (chest): Some lymph nodes show an enlarged short-axis diameter (close to or exceeding 1 cm), with a nearly round shape. For smaller lymph nodes, CT sensitivity is limited, and suspicion primarily depends on changes in their shape and size.
4. PET-CT: Obvious increases in glucose metabolism are seen in the axillary region, certain thoracic lymph node areas, and other suspicious sites, which are highly consistent with tumor metastasis or local recurrence.
5. Pathology (biopsy/postoperative specimen): Tumor cells are observed infiltrating the lymph node cortex, showing high melanin content, consistent with metastatic malignant melanoma.
1. Melanoma Lymph Node Metastasis: Based on the patient’s confirmed history of malignant melanoma, local malignant skin lesion presentation, and the imaging findings of round lymph nodes with disordered blood flow, this is the most likely diagnosis.
2. Lymph Node Metastasis from Other Malignant Tumors: If multiple lymph nodes are enlarged in different regions, other malignancies (e.g., lymphoma, metastatic carcinoma) should be considered. However, given the patient’s primary lesion, melanoma is most indicative.
3. Inflammatory Lymph Node Enlargement: Lymph nodes can enlarge with acute or chronic infection and exhibit abundant blood flow, but they are usually more elliptical in shape and clearly associated with symptoms of infection. In this case, imaging findings more strongly suggest tumor metastasis.
Considering the patient’s history of malignant melanoma, suspicious lymph node hypermetabolism on ultrasound and PET-CT, and pathological findings, the most likely final diagnosis is: melanoma lymph node metastasis.
1. Treatment Strategy
- Surgical Treatment: If both pathology and imaging suggest lymph node metastasis, consider wide excision of the primary lesion (or ensure the original incision is extended sufficiently) and lymph node dissection. If a sentinel lymph node biopsy has already been performed, determine whether to proceed with regional lymph node dissection based on the pathology results.
- Combined Therapy: For patients confirmed to have lymphatic spread or a high risk of distant metastasis, postoperative immunotherapy (e.g., PD-1 inhibitors) and/or targeted therapy (e.g., BRAF/MEK inhibitors) may be considered to reduce the risk of recurrence.
- Radiation Therapy: For high-risk cases or those with residual local lesions, local radiotherapy can be considered to enhance control.
- Follow-up and Monitoring: After surgical and combined therapy, regular imaging examinations (ultrasound, CT, or PET-CT) and blood tests for biomarkers are necessary for early detection of recurrence or new metastases.
2. Rehabilitation and Exercise Prescription
A. Early Postoperative Period (Wound Healing Phase):
Disclaimer: This report is a reference analysis based on current information and does not replace face-to-face consultation or specialist medical advice. Specific diagnoses and treatment plans should be determined in conjunction with the comprehensive assessment of a professional medical institution.
Two-Metastatic axillary lymph nodes in a patient affected by melanoma
