Dual Targeting of the PDZ1 and PDZ2 Domains of MDA-9/Syntenin Inhibits Melanoma Metastasis.

Genome-wide gene expression analysis and animal modeling indicate that melanoma differentiation associated gene-9 (mda-9, Syntenin, Syndecan binding protein, referred to as MDA-9/Syntenin) positively regulates melanoma metastasis. The MDA-9/Syntenin protein contains two tandem PDZ domains serving as a nexus for interactions with multiple proteins that initiate transcription of metastasis-associated genes. Although targeting either PDZ domain abrogates signaling and prometastatic phenotypes, the integrity of both domains is critical for full biological function. Fragment-based drug discovery and NMR identified PDZ1i, an inhibitor of the PDZ1 domain that effectively blocks cancer invasion in vitro and in vivo in multiple experimental animal models. To maximize disruption of MDA-9/Syntenin signaling, an inhibitor has now been developed that simultaneously binds and blocks activity of both PDZ domains. PDZ1i was joined to the second PDZ binding peptide (TNYYFV) with a PEG linker, resulting in PDZ1i/2i (IVMT-Rx-3) that engages both PDZ domains of MDA-9/Syntenin. IVMT-Rx-3 blocks MDA-9/Syntenin interaction with Src, reduces NF-κB activation, and inhibits MMP-2/MMP-9 expression, culminating in repression of melanoma metastasis. The in vivo antimetastatic properties of IVMT-Rx-3 are enhanced when combined with an immune-checkpoint inhibitor. Collectively, our results support the feasibility of engineering MDA-9 dual-PDZ inhibitors with enhanced antimetastatic activities and applications of IVMT-Rx-3 for developing novel therapeutic strategies effectively targeting melanoma and in principle, a broad spectrum of human cancers that also overexpress MDA-9/Syntenin.

Malignant Proliferating Pilar Tumor: Clinicopathologic, Immunohistochemical, and Molecular Study of 17 Cases.

Proliferating pilar tumors are rare neoplasms that differentiate toward the outer sheath near the isthmus and can rarely undergo malignant transformation. We performed histopathologic evaluation on 26 benign proliferating pilar tumor (BPPT) and 17 malignant proliferating pilar tumor (MPPT). Ki-67 and p53 immunostains were performed on 13 BPPT and 10 MPPT. Six MPPT cases were successfully analyzed by a next-generation sequencing platform which surveyed exonic DNA sequences of 447 cancer genes and 191 regions across 60 genes for rearrangement detection. Patient demographics and clinical characteristics were similar between the BPPT and MPPT groups. Follow-up data of 16 of 17 MPPT (median, 25 mo) showed metastasis in 1 MPPT. The histologic features associated with MPPT include size >2.5 cm, adjacent desmoplastic stroma, small nests or cords of atypical epithelium in surrounding stroma, irregular infiltration or borders, abnormal keratinization, large hyperchromatic nuclei, prominent nucleoli, severe cytologic atypia, nuclear pleomorphism, necrosis, and increased mitotic figures. MPPT harbors copy number gains of 15q and losses of 6p and 6q, findings previously reported in BPPT. However, MPPT harbors frequent TP53 mutations as molecular markers of progression. Different from cutaneous squamous cell carcinoma, MPPT more frequently demonstrates low tumor mutational burden and typically lacks a UV signature, suggestive of a different etiologic pathway than squamous cell carcinoma. In summary, with a median follow-up of 25 months, this study shows that MPPT is a biologically indolent carcinoma with rare metastasis. Molecular analyses suggest a non-UV-related pathogenesis with frequent TP53 aberration.

Cutaneous endosalpingiosis arising from C-section scar: A case report with review of literature.

Endosalpingiosis is a pathologic phenomenon in which non-neoplastic fallopian tube epithelium implants in ectopic locations. It is an uncommon and poorly understood condition, with most cases occurring within the abdominopelvic cavity. Cutaneous presentations of endosalpingiosis are even more rare, with only six cases described in international literature to-date. This report describes an additional case of cutaneous endosalpingiosis. The lesion arose within the scar tissue of a Pfannenstiel incision from 4 years prior in a 24-year old, previously healthy African American female. Punch biopsy of the lesion revealed a cystic mass lined by PAX8+ ciliated columnar cells and a surrounding fibrotic stroma with focal CD10-positivity, consistent with a histopathologic diagnosis of endosalpingiosis. In addition, this report provides a comprehensive review of the other documented cases of cutaneous endosalpingiosis, as well as the proposed pathogenesis, histopathologic and clinical features, and potential treatment avenues for this unique clinical entity.

A 9-year-old girl with blisters on the hands and face: An early presentation of variegate porphyria.

Variegate porphyria (VP) is a rare subtype of porphyrias characterized by dysfunction of enzymes in the heme biosynthesis pathway leading to an accumulation of porphyrins and their precursors. The resulting buildup can manifest as neuropsychiatric symptoms and photosensitive blistering eruptions on sun-exposed skin. We report a case of VP in a 9-year-old girl with many confounding medical factors that warranted alternative explanations for her cutaneous lesions. VP has been reported infrequently in the pediatric population and is associated with more severe neuropsychiatric outcomes compared to adult-onset disease.

Nivolumab-Induced de novo Discoid Lupus Erythematosus.

An increasing number of checkpoint inhibitor-induced subacute cutaneous lupus erythematosus events have been reported. We present the first case of nivolumab-induced discoid lupus erythematosus in a patient with hepatocellular carcinoma. The patient presents with violaceous hypopigmented plaques on the pinna bilaterally, hypopigmented plaques with central hyperpigmentation on the posterior neck, and other hypopigmented plaques on the face, forearms, and hands. For management, nivolumab was held for 2 months, and Plaquenil and topical steroids were added. Nivolumab was resumed with no further progression of DLE lesions and improvement of the skin. It is important to characterize cutaneous side effects to effectively manage them.

Merkel Cell Carcinoma of Unknown Primary: Immunohistochemical and Molecular Analyses Reveal Distinct UV-Signature/MCPyV-Negative and High Immunogenicity/MCPyV-Positive Profiles.

BACKGROUND: Merkel cell carcinomas of unknown primary (MCC-UPs) are defined as deep-seated tumors without an associated cutaneous tumor. Although the distinction has important clinical implications, it remains unclear whether these tumors represent primary tumors of lymph nodes or metastatic cutaneous primaries. METHODS: We compared the immunohistochemical profiles of four groups of MCCs (Merkel cell polyomavirus (MCPyV)-positive UP, MCPyV-negative UP, MCPyV-positive known primary (KP), and MCPyV-negative KP) using B-cell and pre-B-cell markers, cell cycle regulating proteins, follicular stem cell markers, and immune markers, and performed next generation and Sanger sequencing. RESULTS: Virus-positive and virus-negative MCC-UPs exhibited an immunoprofile similar to virus-positive and virus-negative primary cutaneous MCCs, respectively. MCC-UP tumors (both virus-positive and -negative) were immunogenic with similar or even higher tumoral PD-L1 expression and intratumoral CD8 and FoxP3 infiltrates in comparison to MCPyV-positive cutaneous tumors. In addition, similar to primary cutaneous MCCs, MCPyV-negative MCC-UPs exhibited UV signatures and frequent high tumor mutational burdens, whereas few molecular alterations were noted in MCPyV-positive MCC-UPs. CONCLUSIONS: Our results showed distinct UV-signatures in MCPyV-negative tumors and high immunogenicity in MCPyV-positive tumors. Although additional studies are warranted for the MCPyV-positive cases, our findings are supportive of a cutaneous metastatic origin for MCPyV-negative MCC-UP tumors.

Molecular and immunophenotypic characterization of anal squamous cell carcinoma reveals distinct clinicopathologic groups associated with HPV and TP53 mutation status.

Squamous cell carcinoma (SqCC) is the most common malignancy of the anal canal, where it is strongly associated with HPV infection. Characteristic genomic alterations have been identified in anal SqCC, but their clinical significance and correlation with HPV status, pathologic features, and immunohistochemical markers are not well established. We examined the molecular and clinicopathologic features of 96 HPV-positive and 20 HPV-negative anal SqCC. HPV types included 89 with HPV16, 2 combined HPV16/HPV18, and 5 HPV33. HPV-positive cases demonstrated frequent mutations or amplifications in PIK3CA (30%; p = 0.027) or FBXW7 mutations (10%). HPV-negativity was associated with frequent TP53 (53%; p = 0.00001) and CDKN2A (21%; p = 0.0045) mutations. P16 immunohistochemistry was positive in all HPV-positive cases and 3/20 HPV-negative cases (p < 0.0001; sensitivity: 100%; specificity: 85%) and was associated with basaloid morphology (p = 0.0031). Aberrant p53 immunohistochemical staining was 100% sensitive and specific for TP53 mutation (p < 0.0001). By the Kaplan-Meier method, HPV-negativity, aberrant p53 staining, and TP53 mutation were associated with inferior overall survival (OS) (p < 0.0001, p = 0.0103, p = 0.0103, respectively) and inferior recurrence-free survival (p = 0.133, p = 0.0064, and p = 0.0064, respectively). TP53/p53 status stratified survival probability by HPV status (p = 0.013), with HPV-negative/aberrant p53 staining associated with the worst OS, HPV-positive/wild-type p53 with best OS, and HPV-positive/aberrant p53 or HPV-negative/wild-type p53 with intermediate OS. On multivariate analysis HPV status (p = 0.0063), patient age (p = 0.0054), T stage (p = 0.039), and lymph node involvement (p = 0.044) were independently associated with OS. PD-L1 expression (CPS ≥ 1) was seen in 30% of HPV-positive and 40% of HPV-negative cases, and PD-L1 positivity was associated with a trend toward inferior OS within the HPV-negative group (p = 0.064). Our findings suggest that anal SqCC can be subclassified into clinically, pathologically, and molecularly distinct groups based on HPV and TP53 mutation status, and p16 and p53 immunohistochemistry represent a clinically useful method of predicting these prognostic groups.

CYLD mutation characterizes a subset of HPV-positive head and neck squamous cell carcinomas with distinctive genomics and frequent cylindroma-like histologic features.

Mutations in the tumor suppressor CYLD, known to be causative of cylindromas, were recently described in a subset of high-risk (hr) HPV-positive head and neck squamous cell carcinomas (HNSCC). Pathologic and genetic characterization of these CYLD-mutant carcinomas, however, remains limited. Here, we investigated whether CYLD mutations characterize a histopathologically and genomically distinct subset of hrHPV-positive HNSCC. Comprehensive genomic profiling via hybrid capture-based DNA sequencing was performed on 703 consecutive head and neck carcinomas with hrHPV sequences, identifying 148 unique cases (21%) harboring CYLD mutations. Clinical data, pathology reports, and histopathology were reviewed. CYLD mutations included homozygous deletions (n = 61/148; 41%), truncations (n = 52; 35%), missense (n = 26; 18%) and splice-site (n = 9; 6%) mutations, and in-frame deletion (n = 1; 1%). Among hrHPV-positive HNSCC, the CYLD-mutant cohort showed substantially lower tumor mutational burden than CYLD-wildtype cases (n = 555) (median 2.6 vs. 4.4 mut/Mb, p < 0.00001) and less frequent alterations in PIK3CA (11% vs. 34%, p < 0.0001), KMT2D (1% vs. 16%, p < 0.0001), and FBXW7 (3% vs. 11%, p = 0.0018). Male predominance (94% vs. 87%), median age (58 vs. 60 years), and detection of HPV16 (95% vs. 89%) were similar. On available histopathology, 70% of CYLD-mutant HNSCC (98/141 cases) contained hyalinized material, consistent with basement membrane inclusions, within crowded aggregates of tumor cells. Only 7% of CYLD-wildtype cases demonstrated this distinctive pattern (p < 0.0001). Histopathologic patterns of CYLD-mutant HNSCC lacking basement membrane inclusions included nonkeratinizing (n = 22, 16%), predominantly nonkeratinizing (nonkeratinizing SCC with focal maturation; n = 10, 7%), and keratinizing (n = 11, 8%) patterns. The latter two groups showed significantly higher frequency of PTEN alterations compared with other CYLD-mutant cases (38% [8/21] vs. 7% [8/120], p = 0.0004). Within our cohort of hrHPV-positive HNSCCs, CYLD mutations were frequent (21%) and demonstrated distinctive clinical, histopathologic, and genomic features that may inform future study of prognosis and treatment.

Metastasizing basal cell carcinoma: A clinicopathologic and immunohistochemical study of 22 cases.

Basal cell carcinomas metastasize rarely, and there have been limited studies of potential drivers for this metastasis. Epithelial-mesenchymal transition (EMT) may play a role, although this has not been investigated in detail. We reviewed clinicopathologic features of 22 patients with metastasizing basal cell carcinoma (MBCC). Immunohistochemical markers of EMT, including CD44, E-cadherin, claudin, smooth muscle actin, beta-catenin, Twist1, and Oct 3/4, were evaluated on 10 MBCC (primary and metastases) and 18 non-metastasizing BCC. Primary sites included the head and neck, trunk, and extremity, while metastatic sites included lymph nodes, lung, bone, and soft tissue. Of 19 cases with follow-up, the range of follow-up after diagnosis of metastasis was 5 to 248 months (median: 50 months). Two cases were of unknown primary, nine metastases were diagnosed concurrently with primary tumors, and remaining cases showed a median latency between diagnosis of primary and metastatic tumors of 27.5 months (range: 3-81 months). Median survival was 66 months. Compared to non-metastasizing BCC, MBCC demonstrated reduced CD44 expression (primary [P = .0036], metastatic [P = .011]) and increased Twist1 expression (primary, P = .0017). MBCC shows variably aggressive behavior, and reduced CD44 and increased Twist1 expression may indicate significant EMT in metastasizing tumors and signify a metastatic phenotype.

Vulvar Squamous Cell Carcinoma: Comprehensive Genomic Profiling of HPV+ Versus HPV- Forms Reveals Distinct Sets of Potentially Actionable Molecular Targets.

PURPOSE: Vulvar squamous cell carcinoma (vSCC) encompasses two predominant variants: one associated with detectable high-risk strains of human papillomavirus (hrHPV) and a second form often occurring in the context of chronic dermatitis in postmenopausal women. Genomic assessment of a large-scale cohort of patients with aggressive vSCC may identify distinct mutational signatures. MATERIALS AND METHODS: Tumor samples from a total of 280 patients with vSCC underwent hybridization capture with analysis of up to 406 cancer-related genes. Human papillomavirus (HPV) sequences were detected by de novo assembly of nonhuman sequencing reads and aligned to the RefSeq database. Immunohistochemistry for programmed death-ligand 1 (PD-L1) was assessed. RESULTS: One hundred two of 280 vSCCs (36%) contained hrHPV sequences, predominantly HPV 16 (88%). The HPV-positive (HPV+) group was significantly younger (median age, 59 v 64 years; P = .001). Compared with HPV-negative (HPV-) vSCCs, HPV+ tumors showed more frequent pathogenic alterations in PIK3CA (31% v 16%; P = .004), PTEN (14% v 2%; P < .0001), EP300 (14% v 1%; P < .0001), STK11 (14% v 1%; P < .0001), AR (5% v 0%; P = .006), and FBXW7 (10% v 3%; P = .03). In contrast, HPV- vSCCs showed more alterations in TP53 (83% v 6%; P < .0001), TERTp (71% v 9%; P < .0001), CDKN2A (55% v 2%; P < .0001), CCND1 amplification (22% v 2%; P < .0001), FAT1 (25% v 4%; P < .0001), NOTCH1 (19% v 6%; P = .002), and EGFR amplification (11% v 0%; P < .0001), as well as a higher rate of 9p24.1 (PDL1/PDL2) amplification (5% v 1%) and PD-L1 immunohistochemistry high-positive tumor staining (33% v 9%; P = .04). CONCLUSION: Comprehensive molecular profiles of vSCC vary considerably with hrHPV status and may inform patient selection into clinical trials. Sixty-one percent of HPV+ vSCCs had a pathogenic alteration in the PI3K/mTOR pathway, whereas HPV- vSCCs showed alterations in TP53, TERTp, CDKN2A, CCND1, and EGFR, and biomarkers associated with responsiveness to immunotherapy.