Cutaneous borreliosis associated with T cell-predominant infiltrates: a diagnostic challenge.

BACKGROUND: With the exception of erythema migrans, Borrelia infection of the skin manifests much more commonly with B cell-rich infiltrates. T cell-rich lesions have rarely been described. OBJECTIVE: We report a series of 6 patients with cutaneous borreliosis presenting with T cell-predominant skin infiltrates. METHODS: We studied the clinicopathologic and molecular features of 6 patients with T cell-rich skin infiltrates. RESULTS: Half of the patients had erythematous patchy, partly annular lesions, and the other patients had features of acrodermatitis chronica atrophicans. Histopathology revealed a dense, band-like or diffuse dermal infiltrate. Apart from small, well differentiated lymphocytes, there were medium-sized lymphocytes with slight nuclear atypia and focal epidermotropism. An interstitial histiocytic component was found in 4 cases, including histiocytic pseudorosettes. Fibrosis was present in all cases but varied in severity and distribution. In 5 patients, borrelia DNA was detected in lesional tissue using polymerase chain reaction studies. No monoclonal rearrangement of T-cell receptor gamma genes was found. LIMITATIONS: This retrospective study was limited by the small number of patients. CONCLUSION: In addition to unusual clinical presentation, cutaneous borreliosis can histopathologically manifest with a T cell-rich infiltrate mimicking cutaneous T-cell lymphoma. Awareness of this clinicopathologic constellation is important to prevent underrecognition of this rare and unusual presentation representing a Borrelia-associated T-cell pseudolymphoma.

The role of interval nodes in sentinel lymph node mapping and dissection for melanoma patients.

UNLABELLED: In sentinel node (SN) biopsy, an interval SN is defined as a lymph node or group of lymph nodes located between the primary melanoma and an anatomically well-defined lymph node group directly draining the skin. As shown in previous reports, these interval SNs seem to be at the same metastatic risk as are SNs in the usual, classic areas. This study aimed to review the incidence, lymphatic anatomy, and metastatic risk of interval SNs. METHODS: SN biopsy was performed at a tertiary center by a single surgical team on a cohort of 402 consecutive patients with primary melanoma. The triple technique of localization was used-that is, lymphoscintigraphy, blue dye, and gamma-probe. Otolaryngologic melanoma and mucosal melanoma were excluded from this analysis. SNs were examined by serial sectioning and immunohistochemistry. All patients with metastatic SNs were recommended to undergo a radical selective lymph node dissection. RESULTS: The primary locations of the melanomas included the trunk (188), an upper limb (67), or a lower limb (147). Overall, 97 (24.1%) of the 402 SNs were metastatic. Interval SNs were observed in 18 patients, in all but 2 of whom classic SNs were also found. The location of the primary was truncal in 11 (61%) of the 18, upper limb in 5, and lower limb in 2. One patient with a dorsal melanoma had drainage exclusively in a cervicoscapular area that was shown on removal to contain not lymph node tissue but only a blue lymph channel without tumor cells. Apart from the interval SN, 13 patients had 1 classic SN area and 3 patients 2 classic SN areas. Of the 18 patients, 2 had at least 1 metastatic interval SN and 2 had a classic SN that was metastatic; overall, 4 (22.2%) of 18 patients were node-positive. CONCLUSION: We found that 2 of 18 interval SNs were metastatic: This study showed that preoperative lymphoscintigraphy must review all known lymphatic areas in order to exclude an interval SN.

Long-term protective effect of mature DC-LAMP+ dendritic cell accumulation in sentinel lymph nodes containing micrometastatic melanoma.

PURPOSE: In a previous immunohistochemical study of dendritic cells (DC) in sentinel lymph nodes (SLN) draining regressing melanomas, we found that the accumulation of mature DC-LAMP(+) DCs in SLNs was associated with local expansion of antigen-specific memory effector CTLs and the absence of metastasis in downstream lymph nodes. The aim of this study was to investigate the prognostic importance of the maximal density of mature DCs in SLNs. EXPERIMENTAL DESIGN: A total of 458 consecutive patients with micrometastatic melanoma within SLNs were eligible for analysis. The maximal density of mature DC-LAMP(+) DCs was evaluated by three independent observers and categorized into three classes (<100, 100 to <200, and >or=200/mm(2)). RESULTS: There was excellent interobserver reproducibility for maximum density of mature DC-LAMP(+) DC scores (kappa score = 0.82). There were differences in the maximal density scores and staining intensity according to the treating melanoma center (P < 0.001). The higher the mature DC density in the SLN is, the longer is the duration of survival [P = 0.047; hazard ratio, 0.70; 95% confidence interval, 0.50-1.00]. Adjusted by thickness and ulceration, the prognostic importance of DC density was lower (P = 0.36). CONCLUSION: This study is the first to report the prognostic value of DC-LAMP(+) DC counts in SLNs containing metastatic melanoma. Patients with a high density of mature DCs (>or=200/mm(2)) have the lowest risk of death. It also provides evidence that a lack of maturation in the SLNs is important in biological facilitation of melanoma progression.

Selective accumulation of mature DC-Lamp+ dendritic cells in tumor sites is associated with efficient T-cell-mediated antitumor response and control of metastatic dissemination in melanoma.

The clinical relevance of dendritic cells (DCs) at the tumor site remains a matter of debate concerning their role in the generation of effective antitumor immunity in human cancers. We performed a comprehensive immunohistochemical analysis using a panel of DC-specific antibodies on regressing tumor lesions and sentinel lymph nodes (SLNs) in melanoma patients. Here we show in a case report involving spontaneous regression of metastatic melanoma that the accumulation of DC-Lamp+ DCs, clustered with tumor cells and lymphocytes, is associated with local expansion of antigen-specific memory effector CTLs. These findings were extended in a series of 19 melanoma-positive SLNs and demonstrated a significant correlation between the density of DC-Lamp+ DC infiltrates in SLNs with the absence of metastasis in downstream lymph nodes. This study, albeit performed in a limited series of patients, points to a pivotal role of mature DCs in the local expansion of efficient antitumor T-cell-mediated immune responses at the initial sites of metastasis and may have important implications regarding the prognosis, staging, and immunotherapy of melanoma patients.