Clinicopathologic correlation of dermatologic diseases in patients with darker pigmentation

OBJECTIVES

Cutaneous diseases that disproportionately affect patients with darker pigmentation and their histologic features are historically understudied and undertreated. This review article aims to highlight the key clinical features, histopathology, and diagnostic pearls of several cutaneous diseases that commonly present in patients with darker pigmentation.

METHODS

A literature search was conducted, and a list of cutaneous diseases that frequently affect patients with darker pigmentation was compiled. A group of experts expounded upon those that were most common or misdiagnosed according to scientific evidence and clinical practice.

RESULTS

The diseases were divided into hypopigmented disorders, hyperpigmented disorders, scarring disorders, and alopecic disorders. Within each category, the etiology, clinical features, histopathology, and key histologic differential diagnoses are described and discussed.

CONCLUSIONS

As many clinicians are taught that there are no effective treatment options or that these diseases are considered "cosmetic" in nature, patients often do not get a thorough medical workup or skin biopsy. This article aims to decrease the knowledge gap and serve as a resource for anyone involved in the care of patients with these cutaneous conditions.

Giant cell tumor of bone in the pediatric population: a retrospective study highlighting cases of metaphyseal only location and increased local recurrence rates in skeletally immature patients

OBJECTIVE

To describe the presentation of giant cell tumors (GCT) of the bone in the pediatric population to (1) improve the differential diagnosis of pediatric bone tumors and (2) identify the origin of GCT. Understanding the origin of bone tumors assists in establishing appropriate diagnoses and recommending treatment options. This is particularly important in children, where evaluating the need for invasive procedures is balanced with the desire to avoid overtreatment. GCT have historically been considered epiphyseal lesions with potential metaphyseal extension. Therefore, GCT may be inappropriately excluded from the differential diagnosis of metaphyseal lesions in the skeletally immature.

MATERIALS AND METHODS

We identified 14 patients from 1981 to 2021 at a single institution who had histologic confirmation of GCT and were less than 18 years old at diagnosis. Patient characteristics, tumor location, surgical treatment, and local recurrence rates were collected.

RESULTS AND CONCLUSIONS

Ten (71%) patients were female. Eleven (78.6%) were epiphysiometaphyseal (1 epiphyseal, 4 metaphyseal, 6 epiphysiometaphyseal). Five patients had an open adjacent physis, of which three (60%) had tumors confined solely to the metaphysis. Of the five patients with open physis, four (80%) developed local recurrence while only one patient (11%) with a closed physis had local recurrence (p value = 0.0023). Our results illustrate that for the skeletally immature, GCT can (and in our results more commonly did) occur in the metaphyseal location. These findings suggest that GCT should be included in the differential diagnosis of primary metaphyseal-only lesions in the skeletally immature.

Tumor-intrinsic NLRP3-HSP70-TLR4 axis drives premetastatic niche development and hyperprogression during anti-PD-1 immunotherapy

The tumor-intrinsic NOD-, LRR- and pyrin domain-containing protein-3 (NLRP3) inflammasome-heat shock protein 70 (HSP70) signaling axis is triggered by CD8⁺ T cell cytotoxicity and contributes to the development of adaptive resistance to anti-programmed cell death protein 1 (PD-1) immunotherapy by recruiting granulocytic polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) into the tumor microenvironment. Here, we demonstrate that the tumor NLRP3-HSP70 axis also drives the accumulation of PMN-MDSCs into distant lung tissues in a manner that depends on lung epithelial cell Toll-like receptor 4 (TLR4) signaling, establishing a premetastatic niche that supports disease hyperprogression in response to anti-PD-1 immunotherapy. Lung epithelial HSP70-TLR4 signaling induces the downstream Wnt5a-dependent release of granulocyte colony-stimulating factor (G-CSF) and C-X-C motif chemokine ligand 5 (CXCL5), thus promoting myeloid granulopoiesis and recruitment of PMN-MDSCs into pulmonary tissues. Treatment with anti-PD-1 immunotherapy enhanced the activation of this pathway through immunologic pressure and drove disease progression in the setting of Nlrp3 amplification. Genetic and pharmacologic inhibition of NLRP3 and HSP70 blocked PMN-MDSC accumulation in the lung in response to anti-PD-1 therapy and suppressed metastatic progression in preclinical models of melanoma and breast cancer. Elevated baseline concentrations of plasma HSP70 and evidence of NLRP3 signaling activity in tumor tissue specimens correlated with the development of disease hyperprogression and inferior survival in patients with stage IV melanoma undergoing anti-PD-1 immunotherapy. Together, this work describes a pathogenic mechanism underlying the phenomenon of disease hyperprogression in melanoma and offers candidate targets and markers capable of improving the management of patients with melanoma.

An Atypical Myelomonocytic Cell Infiltrate: Use of Next-Generation Sequencing to Diagnose Indeterminate Cell Histiocytosis

ABSTRACT

Indeterminant cell histiocytosis (ICH) is a rare lymphoproliferative disorder that demonstrates features of Langerhans and non-Langerhans cell histiocytoses and diagnosis can be challenging. We present a case of a 62 year old woman with a generalized eruption of erythematous papules on the face, trunk and extremities. Skin biopsies demonstrated a dermal mononuclear cell infiltrate with monocytic (CD4, CD33), histiocytic (CD68, CD163), and dendritic cell (CD1a) immunophenotype but negative for Langerhans' cell marker (CD207). The differential diagnosis included leukemia cutis and ICH, and further workup revealed a normal bone marrow biopsy. To confirm the diagnosis of ICH, next generation sequencing with ETV3-NCOA2 gene fusion was performed and was positive. The patient's condition improved with methotrexate and narrow band UVB phototherapy. Our case adds to the existing literature supporting the use of next-generation sequencing to test for ETV3-NCOA2 gene fusion in suspected cases of ICH.

c-AMP/MAPK dysregulation and its impact on survival and response to immunotherapy in advanced melanomas

3086

Background: Immunotherapies blocking the interaction of CTLA-4 or Programmed Death 1 (PD-1) with their ligands are the standard of care for advanced MEL although many pts fail to benefit from immunotherapy. Herein, we seek to identify epigenetic and genetic signatures associated with lack of response in patients treated with immunotherapy . Methods: We performed whole exome sequencing of 580 cancer-related genes and whole-genome DNA methylation arrays targeting > 850k CpG sites covering promoters, enhancers, and transcription factor sites in 28 MEL samples from patients treated with PD-1 +/- CTLA-4 inhibitors. Findings were correlated with collected clinical history. Results: Findings are summarized in the table . Unsupervised clustering and multi-parametric analysis showed a distinct methylation signature independent of age, sex, stage, site of metastasis, or type of treatment (adj. p<0.01). Pathway analysis identified c-AMP/MAPK and PI3K-Akt signaling pathways (adj. p=2.10E-05 and 8.19E-06, respectively) enrichment in non-responders . This coincided with significant increase of mutational events in c -AMP/MAPK and PI3K-Akt pathways (p= 0.0001) including deleterious events affecting PDE4DIP (p=0.0002), a negative regulator of mTORC1, in non-responders. C-AMP/MAPK/PI3K genomic alterations were associated with a worse OS and PFS but not worse response rate (p=0.04, p=0.01, and p=0.20). PDE4DIP deleterious events were associated with decreased response rate, worse OS and PFS (p=0.002; p=0.002;p=0.00003). Conclusions: Convergent epigenetic dysregulation of cAMP/MAPK signaling and inactivation of PDE4DIP is associated with worse outcome and lack of response to immunotherapy, respectively. [Table: see text]

BCAT1 and miR-2504: novel methylome signature distinguishes spindle/desmoplastic melanoma from superficial malignant peripheral nerve sheath tumor

Superficial/cutaneous malignant peripheral nerve sheath tumor is a rare soft tissue neoplasm that shares morphological, immunohistochemical, and molecular features with spindle/desmoplastic melanoma. We aimed to identify a methylome signature to distinguish these two entities. We analyzed 15 cases of spindle/desmoplastic melanoma and 15 cases of cutaneous malignant peripheral nerve sheath tumor in 23 men and 7 women. DNA from formalin-fixed, paraffin-embedded tissues was extracted and processed using the Illumina Infinium Methylation EPIC array interrogating 866,562 CpG sites. Using a home-grown informatics pipeline, we identified differentially methylated positions between the two entities. Functional network analysis for enrichment signatures was performed using DAVID tools. Identified differentially methylated positions were compared with the Cancer Genome Atlas's cutaneous melanoma dataset and a recently published malignant peripheral nerve sheath tumor dataset to assess the specificity of the identified signature. Unsupervised hierarchical clustering showed different patterns of methylation in cutaneous malignant peripheral nerve sheath tumor and spindle/desmoplastic melanoma. Two probes, cg20783223 and cg13332552, colocalized in the promoter region of BCAT1 and miR-2504. Pathway analysis highlighted enrichment in a subset of genes involved in breast and gastric cancer centered on BCAT1 and downstream activated genes in the mTOR pathway. Our study identifies BCAT1 as a novel methylome signature distinguishing spindle/desmoplastic melanoma from cutaneous malignant peripheral nerve sheath tumor.

Abstract B166: Investigating the effect of CDK4/6 and MDM2 inhibition on melanoma

Introduction: The purpose was to investigate how inhibition of MDM2 and CDK4/6 would affect growth of melanoma tumors with deleted CDKN2A in vivo. Methods: B16F0 and WM115 cells were cultured with increasing concentrations of MDM2 inhibitors nutlin-3a, RG7112, or RG7388. Viability was monitored by CellTiter-Blue assay. Induction of p21, MDM2, and BAX expression was monitored by qRT-PCR. C57BL/6J mice (n=40) were injected subcutaneously into both flanks with 50,000 B16F0 cells, a CDKN2A-deficient mouse melanoma cell line. Tumors grew for one week, then mice were randomized into four treatment groups: vehicle (100 µL 0.5% methylcellulose) (n=10), CDK4/6 inhibitor palbociclib 100 mg/kg (n=10), RG7388 150 mg/kg (n=10), and combination palbociclib 100 mg/kg + RG7388 150 mg/kg (n=10). Drugs were given daily via oral gavage. Tumor volumes were measured every 2-3 days, and mice with tumors &gt;15 mm in diameter were euthanized. After 12 days of therapy, tumors were excised and weighed. At the time of euthanasia, mice were bled to evaluate AST and ALT levels. Four tumors per group were randomly selected for H&E staining to evaluate necrosis and IHC for CD3 (T cell marker), Ki67 (proliferation marker), and cleaved caspase 3 (apoptosis marker). The percent of necrosis and number of cells that were positive on IHC were evaluated by a pathologist blinded to the groupings. A mixed-effects model was used to compare tumor growth rate and tumor weights. Kruskal-Wallis and post-hoc Wilcoxon were used for other analyses. Results: In vitro experiments showed RG7388 was the most potent inhibitor of B16F0 and WM115 viability and the strongest inducer of p21 and MDM2. In vivo experiments revealed B16F0 tumor growth rate was significantly reduced in mice treated with palbociclib (p&lt;0.001), RG7388 (p=0.0012), and the combination regimen (p&lt;0.001) compared to those that received the vehicle. Comparing tumor weights to the vehicle group, tumors in the RG7388 (p=0.0281) and combination (p=0.0412) groups weighed significantly less. The drugs did not cause toxicity when used alone or combined based on AST and ALT. Tumors in the RG7388 group had fewer Ki67-positive cells than those in the vehicle (p&lt;0.05) and combination (p&lt;0.01) groups at the endpoint. There was no difference in cleaved caspase 3 expression, necrosis, or CD3 cell infiltration between groups at treatment endpoint. Conclusion: Each therapy reduced tumor growth rate compared to the control and reduced the final tumor weight with the exception of palbociclib-alone-treated tumors, which did not weigh less than control tumors after 12 days of treatment. The reduced growth rate was not associated with changes in apoptosis by cleaved caspase 3 staining or necrosis at the endpoint. Only RG7388-treated tumors showed decreased Ki67 staining. It may be that palbociclib and the combination regimen reduced growth by other means or that the contribution of Ki67-positive nontumor cells skewed the results. Palbociclib and the combination therapy group did not show an increase in TIL recruitment based on CD3 IHC analysis at the endpoint. However, it is likely that T-cell recruitment peaks early in the therapy regimen. We conclude that RG7388, and RG7388 combined with palbociclib, reduced B16 melanoma tumor growth in vivo. Future efforts should include earlier time point analyses of multiplex FACS to characterize full immune filtrate in the tumor over time as well as analyses of multiple cell lines.

Citation Format: Lauren Slesur, Anna Vilgelm, Rami Al-Rohil, Ann Richmond. Investigating the effect of CDK4/6 and MDM2 inhibition on melanoma [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B166.

Extreme Eyelid Lymphedema Associated With Rosacea (Morbihan Disease): Case Series, Literature Review, and Therapeutic Considerations

PURPOSE

To describe severe lymphedema of the eyelids, known as Morbihan disease, a previously characterized but infrequently reported and poorly understood entity related to rosacea that features solid mid-facial and eyelid lymphedema.

METHODS

Retrospective chart review, histopathologic and immunohistochemical analysis, and pertinent literature consideration.

RESULTS

Five cases of Morbihan disease were identified. Histopathologic examination revealed pleomorphic perivascular and perilymphatic inflammation with profound lymphangiectasis and lymph stasis, thus suggesting elements of both rosacea and localized, chronic lymphedema. Multiple therapeutic interventions were performed including systemic anti-inflammatory therapy, surgical debulking, and corticosteroid injection.

CONCLUSIONS

Extreme eyelid edema associated with characteristic skin changes and histopathologic findings represents an entity known as Morbihan disease which is rare and difficult to treat. While multiple modalities have been employed with variable results, future therapeutic considerations may include the use of targeted biologic agents.

Abstract 588: Advanced molecular characterization of severe autoimmune toxicities associated with checkpoint inhibitor therapies

Immune checkpoint inhibitors (ICIs) have made a profound impact on the treatment of a variety of cancers. However, as with any systemic treatment, toxicities are inevitable. With most classes of cancer therapies, toxicities are relatively predictable based on clinical trial safety data and therefore can be handled with prophylactic or supportive care measures. However, ICIs are unique in their ability to cause rare but severe auto-immune toxicities. The molecular underpinnings of these toxicities, as well as unique features of the patient, tumor, or affected tissue, have not been extensively explored. We recently reported a small case series of two patients with myocarditis resulting in death arising following combination ICI therapy (Johnson et al, N Engl J Med, 2016). High lymphocytic infiltration, coupled with PD-L1 expression was present in the affected myocardium and skeletal muscle. Common T cell clones were identified between the affected tissue and tumor, and abnormal expression of muscle-specific transcripts was identified in the associated tumor, suggesting release of peripheral tolerance to tumor-expressed self-antigens.To expand upon our reported study, we collected healthy and afflicted tissue from a series of cancer patients with immune-related colitis, myocarditis (MC), and encephalopathy following ICI treatment. We hypothesize that molecular analysis of these tissues will identify causal factors in the etiology of these toxicities, and how to better predict, prevent, and treat them. Thus, we performed molecular characterization of the immune infiltrate and diseased tissue microenvironment. A total of 20 affected (colon, cardiac, brain) and non-diseased control specimens were examined by spatial digital profiling (nanoString). This process generates a spatial heatmap of digital counts of 20 selected immunology and cellular markers and proteins across each specimen. Using this technology, the landscape of inflammation in ICI-affected organs can be resolved for insights into the mechanism whereby ICI-mediated auto-immunity occurs. Targeted RNAseq for selected immuno-oncology mRNA targets was also performed. In initial RNA sequencing analyses of MC cases, affected myocardium, skeletal muscle, and patient-matched tumors all demonstrated expression of immune activation markers (e.g. interferon-gamma and granzyme B), expression of PD-L1, and muscle-specific genes. In the expanded population, including colitis, digital spatial profiling analyses and targeted NGS (RNAseq) are underway. Although data analyses are incomplete at the time of this abstract, this work will be the largest and most comprehensive analysis of the molecular underpinnings of ICI-mediated auto-immune toxicity reported to date. These data should offer clarity in the mechanisms and features of these adverse events, how to prevent or predict them with precision medicine, and how to treat them when they do occur.

Citation Format: Justin M. Balko, Daniel Y. Wang, Yu Wang, Rami Al-Rohil, Margaret Compton, Jeffery A. Sosman, Igor Puzanov, Bret Mobley, Robert D. Hoffman, Yaomin Xu, Javid J. Moslehi, Chanjuan Shi, Douglas B. Johnson. Advanced molecular characterization of severe autoimmune toxicities associated with checkpoint inhibitor therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 588. doi:10.1158/1538-7445.AM2017-588

New routes to targeted therapy of intrahepatic cholangiocarcinomas revealed by next-generation sequencing

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is a subtype of primary liver cancer that is rarely curable by surgery and is rapidly increasing in incidence. Relapsed ICC has a poor prognosis, and current systemic nontargeted therapies are commonly extrapolated from those used in other gastrointestinal malignancies. We hypothesized that genomic profiling of clinical ICC samples would identify genomic alterations that are linked to targeted therapies and that could facilitate a personalized approach to therapy.

METHODS

DNA sequencing of hybridization-captured libraries was performed for 3,320 exons of 182 cancer-related genes and 36 introns of 14 genes frequently rearranged in cancer. Sample DNA was isolated from 40 μm of 28 formalin-fixed paraffin-embedded ICC specimens and sequenced to high coverage.

RESULTS

The most commonly observed alterations were within ARID1A (36%), IDH1/2 (36%), and TP53 (36%) as well as amplification of MCL1 (21%). Twenty cases (71%) harbored at least one potentially actionable alteration, including FGFR2 (14%), KRAS (11%), PTEN (11%), CDKN2A (7%), CDK6 (7%), ERBB3 (7%), MET (7%), NRAS (7%), BRCA1 (4%), BRCA2 (4%), NF1 (4%), PIK3CA (4%), PTCH1 (4%), and TSC1 (4%). Four (14%) of the ICC cases featured novel gene fusions involving the tyrosine kinases FGFR2 and NTRK1 (FGFR2-KIAA1598, FGFR2-BICC1, FGFR2-TACC3, and RABGAP1L-NTRK1).

CONCLUSION

Two thirds of patients in this study harbored genomic alterations that are associated with targeted therapies and that have the potential to personalize therapy selection for to individual patients.