Citations

Abstract: Immune checkpoint inhibitors are increasingly being used in the treatment of various solid organ and hematologic malignancies. Dermatologic toxicities associated with programmed cell death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) therapy have been widely reported in the literature. It is important for clinicians to be aware of these toxicities to ensure prompt recognition and treatment. Herein, we present the clinical, histopathologic, and immunofluorescence findings of 3 patients diagnosed with lichen planus pemphigoides (LPP) after treatment with anti-PD-1 inhibitors. We also reviewed the literature and summarize 7 previously reported cases of LPP associated with anti-PD-1 and anti-PD-L1 inhibitors. LPP was diagnosed at a median time of 24.4 weeks (range: 4–78 weeks) after initiation of immunotherapy. Clinical findings included papules, plaques, erosions, vesicles, and bullae on the trunk and extremities. Oral involvement was present in half the cases. Histopathologic features of immunotherapy-induced LPP included lichenoid or vacuolar interface dermatitis, the presence of eosinophils, and subepidermal bullae. Direct immunofluorescence demonstrated linear deposition of immunoglobulin G (IgG) or C3. Indirect immunofluorescence demonstrated linear IgG along basement membrane zone on monkey esophagus in 2 cases and linear IgG on the epidermal side of salt split skin in 3 cases. Serum anti-BP180 was elevated in all cases in which enzyme-linked immunosorbent assay was performed.

BACKGROUND Dermatofibrosarcoma protuberans (DFSP) is a soft tissue tumor with slow infiltrative growth and local recurrence if inadequately excised. OBJECTIVE To compare long-term outcomes after Mohs micrographic surgery (MMS) and wide local excision (WLE). MATERIALS AND METHODS Records of patients with DFSP surgically treated with WLE or MMS from January 1955 through March 2012 were retrospectively reviewed. RESULTS Mean follow-up for patients treated with MMS (n = 67) and WLE (n = 91) was 4.8 and 5.7 years, respectively. Twenty-eight patients (30.8%) with WLE had recurrence (mean, 4.4 years), whereas only 2 (3.0%) with MMS had recurrence (1.0 and 2.6 years). Recurrence-free survival rates at 1, 5, 10, and 15 years were significantly higher with MMS (p < .001). Mean preoperative lesion sizes were similar (5–6 cm) between the 2 groups, whereas mean (standard deviation) postoperative defect sizes were 10.7 (4.3) cm and 8.8 (5.5) cm for WLE and MMS, respectively (p = .004). Primary closure was used for 73% of MMS cases, whereas WLE more commonly used flaps, grafts, or other closures (52%). Two Mohs layers typically were required for margin control. CONCLUSION Surgical excision with meticulous histologic evaluation of all surgical margins is needed for DFSP treatment to achieve long-term high cure rates and low morbidity.

Frozen section pathology is routinely used for margin assessment of non‐melanoma skin cancer ( NMSC ). Frozen section can also be used for the primary diagnosis of several skin lesions. Limited data exist on the accuracy of frozen section in the diagnosis of NMSC . We performed a retrospective chart review of 300 cases in which frozen section diagnoses were compared with permanent section diagnoses of NMSC . Frozen section and permanent section pathology were concordant 83.3% of the time, with the highest concordance rates noted for basal cell carcinoma (145/153, 95%). Our results show a high level of concordance between frozen section and corresponding permanent section pathology diagnosis for NMSC . The rapidity of frozen section tissue processing and pathology reporting makes this technique useful in dermatologic practice for immediate diagnosis and management of NMSC . Further studies should explore strategies to decrease or eliminate discrepancies between frozen and permanent section diagnosis.