Immunotherapy (Cemiplimab)-Induced Bullous Pemphigoid: A Possible Pitfall in 18F-FDG PET/CT.

ABSTRACT: A 78-year-old man with multiple squamous cell carcinomas of the skin underwent 18F-FDG-PET/CT for restaging after 4 cycles of cemiplimab. The scan showed new disseminated FDG-avid skin lesions. Dermatologic examination and biopsy revealed bullous pemphigoid. Discontinuation of cemiplimab and treatment with corticosteroids led to clinical improvement, after which treatment with cemiplimab was resumed. A broad spectrum of inflammatory adverse events can occur in patients treated with immune checkpoint inhibitors, and FDG avidity of these lesions may mimic metastases. Knowledge of such imaging pitfalls is essential for interpreting 18F-FDG-PET/CT, particularly if they occur in the same organ as the primary tumor.

Pityriasis rubra pilaris as a systemic disease.

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disorder of unknown etiology, initially described in 1835. It is characterized by keratotic follicular papules, well-demarcated salmon-colored erythematous scaly plaques interspersed with distinct islands of uninvolved skin, and palmoplantar keratoderma. Is PRP a systemic disease? Skin is mainly affected in PRP. Despite its clinical heterogeneity, PRP could be associated with a variety of rheumatologic, infectious, neoplastic, and other extracutaneous manifestations. We accept the hypothesis of not only an association but also a causative relation between skin and systemic manifestations with possible common underlying pathomechanisms such as systemic immunologic processes and superantigen mimicry.

Sequential somatic mutations upon secondary anti-HER2 treatment resistance in metastatic ERBB2S310F mutated extramammary Paget's disease.

Metastatic extramammary Paget's disease is a rare adenocarcinoma with poor prognosis. Several reports of human epidermal growth factor receptor 2 alterations point to its pathogenic role in the disease. However, the occurrence of treatment resistance to anti-HER2 therapy demand the need for further knowledge. We report of a patient with metastatic penoscrotal extramammary Paget's disease, with an ERBB2S310F mutation, in which near complete response was achieved upon treatment with trastuzumab and carboplatin. However, after 10 cycles of trastuzumab and carboplatin, widespread metastasis re-occurred. Analysis of a newly developing metastasis revealed additional genomic alterations including ERBB3A232V and PIK3CAG106V point mutations as well as MET and CDK6 amplification, providing a potential mechanism of acquired treatment resistance. Therefore, ERBB family inhibitor afatinib was initiated. Unfortunately, the patient succumbed to disease-related complications shortly after treatment initiation. This is the first report of ERBB2S310F mutated, metastatic extramammary Paget's disease with secondary resistance to trastuzumab / carboplatin, potentially due to additional acquired genomic alterations. This case contributes to the growing evidence of HER2 in the pathogenesis of metastatic extramammary Paget's disease and emphasizes the importance of repetitive, genomic analysis in rare diseases.

Secretory Carcinoma of the Skin: Report of 6 Cases, Including a Case With a Novel NFIX-PKN1 Translocation.

Secretory carcinoma of the skin is a rare adnexal carcinoma, which is morphologically and immunohistochemically identical to secretory carcinoma of the breast and is associated with the presence of t (12;15) translocation, resulting in the ETV6-NTRK3 gene fusion. Nineteen cases of primary cutaneous secretory carcinoma have been previously published in the literature. In this study, we describe 6 new cases of secretory carcinoma of the skin. The study group consisted of 5 female patients and 1 male patient, ranging in age from 57 to 98 years (mean: 74.2, median: 74). Locations included the axilla (2), neck, eyelid, thigh, and nipple base, each one. Microscopically, all but 1 tumor were well circumscribed and nonencapsulated and exhibited characteristic abundant secretions within the microcystic and tubular spaces comprised by bland oval, round to cuboidal neoplastic cells. In addition, solid areas and focal pseudopapillae were seen, and, in 1 case, a focal mucinous component with small lakes of mucin containing small tumor nests or tubules of the neoplastic cells was present. The remaining neoplasm was mostly solid and papillary, with only few characteristic lumina containing secretions. Immunohistochemically, all cases expressed S-100 protein, mammaglobin, STAT5, GATA3, and NTRK. ETV6-NTRK3 gene fusion was detected in 5 cases, whereas, in the remaining tumor, a novel NFIX-PKN1 gene fusion was found.

Treating insect-bite hypersensitivity in horses with active vaccination against IL-5.

BACKGROUND: Insect-bite hypersensitivity is the most common allergic dermatitis in horses. Excoriated skin lesions are typical symptoms of this seasonal and refractory chronic disease. On a cellular level, the skin lesions are characterized by massive eosinophil infiltration caused by an underlying allergic response. OBJECTIVE: To target these cells and treat disease, we developed a therapeutic vaccine against equine IL-5 (eIL-5), the master regulator of eosinophils. METHODS: The vaccine consisted of eIL-5 covalently linked to a virus-like particle derived from cucumber mosaic virus containing the tetanus toxoid universal T-cell epitope tt830-843 (CMVTT). Thirty-four Icelandic horses were recruited and immunized with 400 µg of eIL-5-CMVTT formulated in PBS without adjuvant (19 horses) or PBS alone (15 horses). RESULTS: The vaccine was well tolerated and did not reveal any safety concerns but was able to induce anti-eIL-5 autoantibody titers in 17 of 19 horses. This resulted in a statistically significant reduction in clinical lesion scores when compared with previous season levels, as well as levels in placebo-treated horses. Protection required a minimal threshold of anti-eIL-5 antibodies. Clinical improvement by disease scoring showed that 47% and 21% of vaccinated horses reached 50% and 75% improvement, respectively. In the placebo group no horse reached 75% improvement, and only 13% reached 50% improvement. CONCLUSION: Our therapeutic vaccine inducing autoantibodies against self IL-5 brings biologics to horses, is the first successful immunotherapeutic approach targeting a chronic disease in horses, and might facilitate development of a similar vaccine against IL-5 in human subjects.

Sarcoid-like reactions in patients receiving modern melanoma treatment.

The development of cancer immunotherapy and targeted therapy has reached an important inflection point in the history of melanoma. Immune checkpoint inhibitors and kinase inhibitors are today's standard of care treatments in advanced melanoma patients. Treatment-related toxicities can be very intriguing and quite challenging. Sarcoidosis is a multisystemic granulomatous disease characterized by an aberrant immune response to unknown antigens, whereas sarcoid-like reactions (SLRs) refer to localized clinical features. We carried out a single-center observational study in patients with stage IIB-IV melanoma treated with BRAF/MEK inhibitors and immune checkpoint inhibitors. A description of the sarcoidosis-related manifestations was provided from patients' records. We observated eight cases of SLRs in a cohort of 200 patients. The clinical courses were characterized by a variety of symptoms, accompanied by cutaneous signs and extracutaneous manifestations such as bilateral, hilar lymphadenopathy. We identified a histologically granulomatous inflammation involving the skin, the lungs, and the lymph nodes. Two patients presented with cutaneous lesions only, and three patients had lung involvement only. Three patients achieved complete and partial response of the melanoma disease, and three patients had stable disease. Disease progression was documented in two patients. The reported immune-related adverse events were mild to severe and in most of the cases were continued without any treatment cessation. SLRs appear during treatment with both kinase and immune checkpoint inhibitors. Awareness of these can avoid misdiagnosis of disease progression and unnecessary treatment changes.

TLR4 as a negative regulator of keratinocyte proliferation.

TLR4 is an innate immune receptor with expression in human skin, keratinocytes as well as squamous cell carcinoma (SCC) of the skin. In the present study we investigate the role of TLR4 as a negative regulator of keratinocyte proliferation. We present here that the expression of TLR4 increased with the differentiation of cultured keratinocytes in a passage-dependent manner or under calcium-rich conditions. Moreover, the down-regulation of TLR4 by specific knockdown increased the proliferation of HaCaT keratinocytes in vitro. In addition, subcutaneously injected HaCaT keratinocytes with shTLR4 formed growing tumors in nude mice. In contrast, we observed lower proliferation and increased migration in vitro of the SCC13 cell line stably overexpressing TLR4 in comparison to SCC13 TLR4 negative cells. In vivo, SCC13 TLR4-overexpressing tumors showed delayed growth in comparison to TLR4 negative tumors. The overexpression of TLR4 in SCC13 tumor cells was followed by phosphorylation of ERK1/2 and JNK and increased expression of ATF3. In gene expression arrays, the overexpression of TLR4 in tumor cells correlated with gene expression of ATF-3, IL-6, CDH13, CXCL-1 and TFPI. In summary, TLR4 negatively regulates the proliferation of keratinocytes and its overexpression reduces tumor growth of SCC cells.

A Report of Two Cases of Solid Facial Edema in Acne.

INTRODUCTION: Solid facial edema (SFE) is a rare complication of acne vulgaris. To examine the clinical features of acne patients with solid facial edema, and to give an overview on the outcome of previous topical and systemic treatments in the cases so far published. METHODS: We report two cases from Switzerland, both young men with initially papulopustular acne resistant to topical retinoids. RESULTS: Both cases responded to oral isotretinoin, in one case combined with oral steroids. Our cases show a strikingly similar clinical appearance to the cases described by Connelly and Winkelmann in 1985 (Connelly MG, Winkelmann RK. Solid facial edema as a complication of acne vulgaris. Arch Dermatol. 1985;121(1):87), as well as to cases of Morbihan's disease that occurs as a rare complication of rosacea. CONCLUSION: Even 30 years after, the cause of the edema remains unknown. In two of the original four cases, a potential triggering factor was identified such as facial trauma or insect bites; however, our two patients did not report such occurrencies. The rare cases of solid facial edema in both acne and rosacea might hold the key to understanding the specific inflammatory pattern that creates both persisting inflammation and disturbed fluid homeostasis which can occur as a slightly different presentation in dermatomyositis, angioedema, Heerfordt's syndrome and other conditions.

Transient Efficacy of Tofacitinib in Alopecia Areata Universalis.

Alopecia areata is a common autoimmune disorder that targets hair follicles. Swarms of lymphocytes surround the basis of the follicles, inducing loss of pigmented terminal hair and subsequently inhibit further hair growth. Depending on the extent of involvement, alopecia areata can be associated with a dramatic reduction of quality of life. Currently, no targeted treatment option is available, and topical immune therapies or immunosuppressive drugs are typically used with mixed success. Recently, several cases of alopecia areata responding to Janus kinase inhibitors were published. Here, we report on a businessman with alopecia areata universalis who was treated with tofacitinib. We observed initial signs of hair regrowth in the same timeframe as previously reported, but efficacy quickly waned again, leading to renewed effluvium. Thus, even though tofacitinib and ruxolitinib are a promising new treatment option, we have yet to learn more about their potential role in each particular patient's individual treatment strategy.

Pyogenic granuloma in patients treated with selective BRAF inhibitors: another manifestation of paradoxical pathway activation.

Cutaneous toxicities under therapy with selective BRAF inhibitors such as vemurafenib or encorafenib (LGX818) are frequent, including plantar hyperkeratosis, squamous cell carcinoma, and second primary melanoma. Pyogenic granuloma is a benign, rapidly growing, eruptive hemangioma that often bleeds and ulcerates. Common causes are mechanical trauma and cast immobilization, as well as multiple drugs such as retinoids and antineoplastic agents. However, the development of pyogenic granuloma under treatment with encorafenib (LGX818) has not yet been reported. These three cases might be further examples for paradoxical activation of the mitogen-activated protein kinase pathway. We report three male patients with metastatic BRAFV600E-mutated melanoma who developed pyogenic granulomas 16, 10, and 12 weeks after treatment initiation with the selective BRAF inhibitors vemurafenib or encorafenib (LGX818). Except for one patient receiving retinoids, the clinical history for other frequent causes of pyogenic granuloma was negative. Pyogenic granulomas are not listed in the drugs investigator brochure but seem to be associated with selective BRAF inhibitors and might be a cutaneous phenomenon of paradoxical mitogen-activated protein kinase pathway activation. This correlation has to be confirmed by further observations.

Acrokeratosis paraneoplastica in serous ovarian carcinoma: case report.

BACKGROUND: Acrokeratosis paraneoplastica is a rare paraneoplastic phenomenon associated with upper aerodigestive tract carcinomas, usually manifesting as psoriasiform keratosis over the acral sites. It is primarily seen in white males above the age of 40 years. Here we report a case of paraneoplastic acrokeratosis in a woman with serous ovarian cancer. To the best of our knowledge, no similar case has been reported previously. CASE PRESENTATION: We report the case of a 60-year-old woman diagnosed with a serous ovarian cancer and complaining of a thickening and peeling of the skin on her feet. Clinical and histological examination, as well as the course of disease, confirmed the diagnosis of a paraneoplastic plantar keratosis. Under systemic chemotherapy with carboplatin and paclitaxel the lesion resolved gradually in concordance with tumour marker CA 125. CONCLUSIONS: We present the reported case of paraneoplastic acrokeratosis associated with advanced high-grade ovarian cancer.

Severe Sweet's Syndrome with Elevated Cutaneous Interleukin-1ß after Azathioprine Exposure: Case Report and Review of the Literature.

Sweet's syndrome (SS) is a dermatosis with systemic symptoms characterized by tender, red nodules or papules, occasionally covered with vesicles, pustules or bullae, usually affecting the upper limbs, face and neck. SS is frequently observed in patients with leukemia or connective tissue diseases, while it is rather seldom in patients with inflammatory bowel disease. The exact pathogenesis of SS is only partially understood. We report the case of a 50-year-old patient with indeterminate colitis, presenting with a febrile diffuse papulopustular and necrotizing skin eruption that healed with significant scarring and appeared 14 days after onset of treatment with azathioprine. Histological examination revealed the presence of features typical of SS, gene expression analysis very high levels of interleukin-1ß (IL-1ß) mRNA in lesional skin, and immunohistochemistry high levels of IL-1ß at the protein level. SS associated with azathioprine is being increasingly reported and is reviewed herein.

New onset of kaposi sarcoma in a human immunodeficiency virus-1-infected homosexual man, despite early antiretroviral treatment, sustained viral suppression, and immune restoration.

This is a rare case of new onset Kaposi sarcoma in a man infected with human immunodeficiency virus (HIV) and receiving antiretroviral treatment since primary HIV infection, with normal CD4(+) cell count and suppressed viral load. The presentation questions the general understanding of Kaposi sarcoma as an acquired immune deficiency syndrome-defining disease occurring predominantly in severely immunocompromised patients infected with HIV.

Persistent photodamage following drug photosensitization in a lung-transplant recipient.

Photosensitivity is a well-known complication of treatment with quinolone antibiotics. Several transient phototoxic drug reactions have been described. We report a case of a persistent phototoxic reaction to ciprofloxacin in a lung-transplant recipient on a long-term immunosuppressive drug regimen.

Collision tumors: CAMEL, METRO and other acronyms.

We describe two exceptional collision tumors, namely: a 63-year-old woman revealing a melanocytic tumor within a trichoblastoma and a 71-year-old woman with a squamous cell carcinoma colonized by dendritic cells of a melanoma. Both neoplasms showed two different tumor components with intimate relationship. The lesions are labeled in a "playful" way with the acronyms METRO (MElanocytic tumor +TRichOblastoma) and CAMEL (CArcinoma +MELanoma) to facilitate memorization.