In-transit intramammary sentinel lymph nodes from malignant melanoma of the trunk.

OBJECTIVE: Our goal was to determine the incidence and outcomes of intramammary in-transit sentinel lymph nodes (IMSLN) from primary malignant melanoma (MM) of the trunk. We hypothesize that regional metastasis to the breast from anterior trunk MM also occurs via the lymphatic system to these intramammary in-transit sentinel lymph nodes. BACKGROUND: MM is the most common solid tumor metastasis to the breast. The mechanism of intramammary (IM) metastasis is generally attributed to hematogenous rather than lymphatic spread. METHODS: We retrospectively reviewed medical records from all patients who underwent selective sentinel lymph node dissection at the UCSF Melanoma Center from 1993 to 2008 after the approval of UCSF Committee on Human Research. Of the 1911 cases, we found 614 patients with primary MM located on the trunk, and queried their medical records for in-transit SLN and SLNs in the breast. Data from preoperative lymphoscintigraphy, intraoperative lymphatic mapping, operative notes, and pathology and clinic notes were gathered. RESULTS: Of the 1911 patients with MM, 169 (8.9%) and 420 (22.0%) had anterior and posterior trunk lesions, respectively, and 25 patients (1.3%) with flank lesions (lateral abdominal wall below the rib cage, above the iliac crest). Of the anterior trunk population, 18 patients had in-transit SLNs. The vast majority of these patients (14 of 18, 77.8%) had in-transit IMSLN. Of patients with posterior trunk melanoma, 27 patients had in-transit nodes with 1 patient having IMSLNs. Of patients with flank melanomas, 3 patients had in-transit nodes with 1 patient having IMSLNs. Interestingly, all patients with IMSLNs had primary lesions located inferior to the breasts. Two of the 16 patients with IMSLNs had micrometastasis to IMSLN; 1 patient died and the other currently is disease free 4 years after initial SLND. Four of the 32 patients with non-IM in-transit nodes had micrometastases to these in-transit nodes. Of all patients with trunk melanomas, 4 patients had micrometastases to axillary SLNs (AxSLNs). Three of the 4 patients with positive AxSLNs also had positive in-transit nodes whereas only half of the patients with positive in-transit SLNs had positive AxSLNs. CONCLUSIONS: IMSLNs exist in the breast. Our results establish an anatomic basis for lymphatic metastasis to the breast from primary cutaneous melanoma mainly from the anterior trunk inferior to the breasts. For anterior trunk melanomas, IMSLNs should not be overlooked during SLND as they may harbor micrometastasis.

Clinical significance of occult metastatic melanoma in sentinel lymph nodes and other high-risk factors based on long-term follow-up.

Selective sentinel lymphadenectomy (SSL) following preoperative lymphoscintigraphy is the most significant recent advance in the management of patients with primary melanoma. This study evaluates the prognostic value of sentinel lymph node (SLN) status and other risk factors in predicting survival and recurrence in patients with primary cutaneous melanoma. From October 1993 to July 1998 a series of 412 patients with primary invasive melanoma underwent SSL at the UCSF/ Mt. Zion Melanoma Center. The outcome of 363 evaluable patients is summarized in this study. The factors related to survival and disease recurrence were analyzed by Cox proportional hazard regression models. The overall incidence of patients with positive SLNs was 18%. Over a median follow-up of 4.8 years, the overall mortality rate in patients with primary cutaneous melanoma was 18.7%, and 74 recurrences occurred (20.4%). Mortality was significantly related to SLN status [HR = 2.06; 95% Confidence interval (CI) 1.18, 3.58], angiolymphatic invasion (HR = 2.21; 95% CI 1.08, 4.55), ulceration (HR = 1.79; 95% CI 1.02, 3.15), mitotic index (HR =1.38; 95% CI 1.01, 1.90), and tumor thickness (HR = 2.20, 95% CI 1.21, 3.99). Factors significantly related to disease-free survival included SLN status (HR = 2.09; 95% CI 1.31, 3.34), tumor thickness (HR = 1.89; 95%. CI 1.20,2.98), and age (HR= 1.26 95% CI 1.08, 1.47). SLN status was the most significant factor for melanoma recurrence and death. Other important predictors include tumor thickness, ulceration, lymphatic invasion, and mitotic index.

Heterogeneous patterns of lymphatic drainage to sentinel lymph nodes by primary melanoma from different anatomic sites.

UNLABELLED: We want to define the patterns of lymphatic drainage for primary melanoma to sentinel lymph nodes (SLNs) based on a large lymphoscintigraphic database. Preoperative lymphoscintigraphy was used to identify and classify SLN drainage basins and patterns of drainage. METHODS: Lymphoscintigraphy using intradermally administered technetium-99m labeled sulfur colloid was performed on 400 consecutive patients with malignant melanoma to define lymphatic drainage channels and draining SLN basins before surgery. Primary tumor sites consisted of head and neck, upper extremity, trunk, and lower extremity. Different types of drainage patterns were classified and correlated with different anatomic sites. RESULTS: SLN(s) were identified in over 98% of the patients, whereas lymphatic drainage channels were successfully identified in 90% of the patients. Drainage from the primary site to a single SLN through a single lymphatic channel (type IA) was seen in 186 of 400 patients (47%) as the most common type. In patients with a single SLN within a single basin (type I-V), the percentage of patients with primary lesions in the head and neck, upper extremity, trunk, and lower extremity regions were 61%, 79%, 55%, and 78%, respectively. In cases of multiple lymphatic channels (type VI-VII), the percentages of patients with primary lesions in the head and neck, upper extremity, trunk, and lower extremity regions were 24%, 8%, 36%, and 19%, respectively. CONCLUSION: Various drainage patterns were noted from primary melanomas in different anatomic sites. Preoperative lymphoscintigraphy is important in establishing the SLN basins for harvesting the SLN(s).

Failure to harvest sentinel lymph nodes identified by preoperative lymphoscintigraphy in breast cancer patients.

Selective sentinel lymphadenectomy dissection has been demonstrated to have high predictive value for axillary staging in breast cancer patients. Preoperative lymphoscintigraphy can localize and facilitate the harvesting of sentinel lymph nodes (SNLs) with a high success rate. The failure rate of selective sentinel lymphadenectomy ranges between 2% and 8%. Details of the failures were seldom addressed. This study analyzes the causes of failure to harvest SLNs in spite of positive preoperative lymphoscintigraphy. From November 1997 through November 2000, 201 female patients with histologically confirmed and operable breast carcinoma underwent selective sentinel lymphadenectomy at the University of California, San Francisco (UCSF) Carol Franc Buck Breast Care Center. Among these patients, 183 (91%) received preoperative lymphoscintigraphy to identify axillary lymph nodes. The causes of failure to harvest the SLNs in this group of patients despite successful preoperative lymphoscintigraphy were analyzed. In our series, the failure rate of SLN identification was 7.0% (14/201). The failure rate for our first year was 11.1% (6/54), second year 9.1% (7/77), and third year 1.4% (1/70). The incidence of failure in spite of positive preoperative lymphoscintigraphy was 3.5% (6/170). The shine-through effect of the primary injection site and failure to visualize a blue lymph node were the main reasons for technical failure. Most of these cases occurred during our learning curve of the procedure. The possibility of failure to get the SLN should be explained to patients before surgery. Axillary lymph node dissection (ALND) should be done if selective SLN dissection is not successful.