[Bullous drug reaction after pembrolizumab administration: two case reports]. / Bullöse Arzneimittelreaktion nach Gabe von Pembrolizumab ­ 2 Fallberichte.

Severe, blistering, adverse drug reactions involving the skin include Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Allopurinol, anticonvulsants, sulphonamide antibiotics and non-steroidal anti-inflammatory drugs in the oxicam class have been repeatedly described as triggers. Increasingly, immunotherapies are also coming into focus as triggers of severe skin reactions. Two patients with bullous skin symptoms after administration of the checkpoint inhibitor pembrolizumab are presented. As the clinical picture does not always allow an unequivocal classification, a histological assessment is often indispensable.

The predictive value of the sentinel lymph node in malignant melanomas.

At the beginning of a lymphogenous metastasizing process in malignant melanomas, the first tumor cells are found in the so-called sentinel lymph node (SLN), defined as the first tumor-draining lymph node. Its removal and histopathological examination enable us to discover metastases of malignant melanomas long before their possibility of detection by any other method. Since the beginning of 1995, we have performed more than 350 gamma-probe-guided sentinel lymphonodectomies (gamma-SLNE), without any clinical evidence of metastases as determined by lymphoscintigraphy. Using gamma-SLNE, the detection and excision of the SLN succeeded in nearly all patients. The SLNs were fixed in formalin, completely cut into 1-mm thin slices and stained for routine H&E histology and with S-100 and HMB-45. In persons with melanomas thinner than 0.75 mm, we never found micrometastases. However, the SLNs were positive in melanomas from 0.76 to 1.50 mm in about 7% of patients, in melanomas from 1.51 to 4.00 mm in about 21% and in tumors thicker than 4 mm in about 44%. In primary melanomas with satellite or in-transit metastases, the SLNs contained metastases in 75% of patients. Normally, a radical lymph node dissection (RLND) follows, as it is considered to be the necessary consequence following detection of tumor cells. The lymph nodes of the RLNDs contained further metastases in about 30% of patients. The probability of the involvement of lymph nodes other than the SLN correlates with the extension of tumor cells in the SLN. During our 4-year-follow-up, we observed only a single lymph node recurrence in a patient with a negative SLN (false negative rate of about 0.4%). The development of systemic metastasis correlates not only with the Breslow tumor thickness, but also with the extent of the involvement of the melanoma metastasis in the SLN. Summarizing, it can be said that gamma-SLNE has revolutionized melanoma surgery. Based on our data, it is absolutely necessary in the staging of malignant melanoma. In our opinion, the existing classification systems for staging lymph node involvement have to be revised in light of the results of SLNE.

Sentinel lymphonodectomy in nonmelanoma skin malignancies.

BACKGROUND: Whereas the value of sentinel lymphonodectomy (SLNE) in malignant melanoma is established, experience with SLNE in nonmelanoma skin cancers is limited. OBJECTIVES: The feasibility of SLNE in nonmelanoma skin tumours is evaluated. METHODS: Thirty-seven patients with high-risk nonmelanoma skin tumours underwent SLNE: 11 squamous cell carcinomas (SCCs), seven Merkel cell carcinomas (MCCs), five cutaneous lymphomas, eight adnexal carcinomas and six other skin cancers, all clinical stage N0. RESULTS: In nine patients (four MCCs, two SCCs, three lymphomas) the sentinel lymph nodes (SLNs) showed histological evidence of microinvolvement. In five of these nine patients, radical lymph node dissection (RLND) was performed, revealing further micrometastases in three patients (two SCCs, one MCC). No patient with negative SLN showed tumour dissemination during the follow-up over a mean of 2.5 years (range 2 months to 4.5 years, median 2.4 years). CONCLUSIONS: Our data provide evidence that SLNE is a minimally invasive and highly sensitive staging tool in selected patients with high-risk nonmelanoma skin cancers.