Search

In the present study, to identify the clinical significance of the cytokeratin (CK) 20 staining pattern in Merkel cell carcinoma (MCC), we retrospectively analyzed the major clinicopathological and immunohistochemical characteristics of 12 cases of MCC. Typical dot-like pattern was seen in eight of our patients, while four patients showed peripheral staining pattern. Interestingly, all cases of MCC with dot-like CK20 tumor cells occurred in the head and neck region, while those with peripheral CK20 pattern tended to be located in other lesions (forearm, knee, or buttock): The difference of frequency in the head and neck regions was statistically significant. Dot-like CK20 staining pattern may therefore be resulted from ultraviolet exposure. Additionally, although without significance, metastasis was more frequent in those with dot-like CK20 than in peripheral CK20 staining: All patients with peripheral CK20 pattern had complete remission by surgical excision with or without radiation therapy. CK20 staining pattern may be a novel predictor of prognosis.

Lymphomatoid papulosis (LyP) is a self-limiting cutaneous T-cell lymphoproliferative disorder that may progress into malignant lymphoma. Most of the previously reported associated lymphomas are primary cutaneous anaplastic large-cell lymphoma and mycosis fungoides with a low mortality rate. We report a case of primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS), associated with LyP after long-term follow up. The patient was a 79-year old Japanese man followed up for 9 years. He suddenly developed a 3-cm ulcerated lesion on his forehead, which was diagnosed as an exacerbation of LyP. The lesion regressed after conservative treatment, but the patient soon developed multifocal pcPTCL-NOS. Thereafter, the patient developed pneumonia and cerebral infarction and died within a few months of the onset of malignant lymphoma. Aggressive cutaneous lymphoma may develop in LyP patients. The present case re-emphasizes the need for careful follow up of patients with persistent LyP., (© 2020 Japanese Dermatological Association.)

Adipophilin (ADP) is a primary protein component of lipid droplets (LDs). For more than half a century, certain types of cancer cells have been known to contain LDs in their cytoplasm. However, the pathological significance of ADP or LDs in cancer remains unclear. In the present study, we investigated the association between ADP and other pathological characteristics in cutaneous malignant melanomas to clarify the role of ADP in melanoma cells. We immunostained whole paraffin sections of primary cutaneous melanomas obtained from 90 cases for ADP, after which we analyzed the correlation between ADP immunohistochemistry (IHC) and patient survival data. We also studied the relationship between the ADP IHC score and in situ hybridization (ISH) score of ADP mRNA, and the Ki67-labeling index (Ki67-LI) by using tissue microarrays consisting of 74 primary cutaneous malignant melanomas, 19 metastasizing melanomas, and 29 melanocytic nevi. Finally, we analyzed the relationship between ADP expression and cell proliferation in cutaneous melanoma cell lines. We found that high ADP expression was associated with poor metastasis-free survival, disease-specific survival, and overall survival rates of patients with cutaneous melanomas (P < 0.05). By linear regression analysis, ADP IHC was correlated with increasing ADP mRNA ISH H-scores and Ki67-LI scores in melanocytic lesions (P < 0.01). ADP IHC and ADP ISH H-scores and Ki67-LI scores were greater in pT3-4 melanomas than in pT1-2 melanomas. In cell-based assays, cells with increased ADP expression showed higher proliferation rates compared with those of low-ADP cells. Thus, ADP expression in malignant melanoma was significantly associated with high cell proliferation and poor clinical prognosis. Our results thus indicate a significant association between ADP and melanoma progression, and we propose that ADP may be a novel marker of aggressive cutaneous melanoma with a lipogenic phenotype.

Although most cases of early cutaneous squamous cell carcinoma (CSCC) are indolent, a small subset metastasize and can be fatal. However, high-risk features of CSCC are controversial, and it is difficult to predict the biological behavior. In this study, we have tested the prognostic significance of tumor budding in CSCCs <4 cm in diameter. Hematoxylin and eosin-stained sections of surgically resected CSCCs (24 metastasizing and 24 nonmetastasizing cases) <4 cm in size were reviewed retrospectively. Tumor bud, defined as an isolated cancer cell or a cluster comprising<5 cells, was counted at a hot spot (1.23 mm), and graded between 1 and 3; grade 1: 0 to 4 buds; grade 2: 5 to 9 buds; and grade 3: ≥10 buds. Cases with grades 2 or 3 were regarded as positive for tumor budding. We found that tumor budding was positive in 83.3% of metastasizing CSCC, and 37.5% of nonmetastasizing CSCC (P<0.01). Moreover, CSCCs with grade 3 tumor budding showed worse disease-specific survival (P<0.01). Regarding interobserver reproducibility, the median κ value for tumor budding was significantly higher than that for histologic differentiation (P<0.01). In conclusion, tumor budding may be a valuable histologic marker for risk stratification of early CSCC in routine practice. Patients with tumor budding positive CSCC may benefit from evaluation and close follow-up for regional node metastasis.

High-risk human papillomavirus (HR-HPV) is known to play an oncogenic role in squamous cell carcinoma (SCC) at certain anatomical sites, namely the uterine cervix, oropharynx, and anogenital skin. However, the association between HR-HPV and nonanogenital cutaneous SCC (CSCC) remains controversial. In this study, we addressed this controversy by performing HR-HPV E6/E7 mRNA in situ hybridization (ISH) on 243 CSCC samples. A cocktail of E6/E7 mRNA ISH probes, recognizing 18 HR-HPV genotypes, was applied to a tissue microarray of paraffin-embedded sections of 154 invasive and 89 in situ CSCC specimens. The anatomical sites of CSCC included the head and neck (n = 100), extremities (n = 100), trunk (n = 25), and anogenitalia (n = 18). We also investigated the correlation between the p16 expression and HR-HPV status by immunohistochemistry. The results of HR-HPV E6/E7 mRNA ISH showed that 5.8% (14/243) of all CSCC samples were positive for HR-HPV, including 66.7% (12/18) of the anogenital and only 0.9% (2/225) of the nonanogenital CSCC samples (P < 0.01). For the detection of diffuse p16 expression by immunohistochemistry, the sensitivity was 100% (14/14 HR-HPV-positive CSCC samples), and the specificity was 72.1% (165/229 HR-HPV-negative specimens). Thus, HR-HPV E6/E7 mRNA was rarely detected in nonanogenital CSCC, making it unlikely that the virus contributes to the pathogenesis of this malignancy. In addition, p16 immunoreactivity has a limited value as a surrogate marker for transcriptionally active HR-HPV in nonanogenital CSCC.

Frequent kinase fusions have been reported in spitzoid neoplasms, approximately 10% of which involve ALK rearrangements. Herein, we report a case of atypical Spitz tumor with a novel MLPH-ALK fusion, which has not been previously reported to contribute to cancer development. The tumor was detected in the right arm of a 40-year-old woman. The novel ALK fusion was identified by a 5'-rapid amplification of cDNA ends-based system optimized for formalin-fixed, paraffin-embedded tissue. Initially, ALK expression was detected by immunohistochemistry using 5A4 antibodies for both sensitive and conventional polymer detection methods. However, the anti-ALK1 antibody, which is commonly used for the diagnosis of ALK-positive anaplastic large cell lymphoma, failed to confirm ALK expression. These results indicated that ALK immunohistochemistry results in ALK-rearranged atypical Spitz tumor may differ based on the type of primary antibody clone, which can be a potential diagnostic pitfall., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: The lipogenic pathway is upregulated in cancer cells, including melanomas. However, the pathological significance of cellular lipids in melanocytic lesions has yet to be determined. In this study, we evaluated intracytoplasmic lipid droplets in melanocytic nevi (MNs) and malignant melanomas via immunohistochemical analysis of adipophilin (ADP), which coats lipid droplets., Methods: One hundred primary cutaneous melanocytic lesions [33 MNs, 17 melanomas in situ (MIS), and 50 invasive melanomas (IMs)] were immunostained for ADP. The intensity score (IS) and proportion score (PS) of ADP staining in each case was recorded semiquantitatively on a scale of 0 to 3+., Results: High ADP expression (IS2/3+ and PS2/3+) was observed in 27 primary cutaneous melanocytic lesions that consisted of 23 IMs, three MISs, and one MN. Consequently, high ADP expression was associated with malignancy (38.8% vs. 3.0%; p < 0.0001). Among the IMs, high ADP expression was more prevalent in pT3/4 than pT1/2 (63.3% vs. 23.8%; p = 0.01) and Stage 3/4 than Stage 1/2 (76.9% vs. 36.8%; p = 0.02)., Conclusions: The majority of the melanocytic lesions with high ADP expression were malignant melanomas in our cohort. Therefore, ADP expression may serve as a sensitive diagnostic marker for malignant melanoma., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Although tumor budding is acknowledged as a risk factor for lymph node metastasis in certain types of carcinoma, it is not well investigated in cutaneous squamous cell carcinomas (SCCs). In this study, we analyzed the correlation between tumor budding and nodal metastasis in cutaneous SCC., Methods: Histopathologic specimens of 15 metastasizing and 144 non-metastasizing cutaneous SCC were retrospectively reviewed. Cut-off point for tumor budding was determined at five or more foci of an isolated cancer cell or a cluster comprising <5 cells /1.23 mm(2) in the invasive front of the tumor under hematoxylin and eosin sections., Results: Tumor budding was positive in 93.3% of metastasizing cutaneous SCC and 25.7% of non-metastasizing cutaneous SCC, respectively (p < 0.0001). In multivariate analysis, tumor budding was an independent risk factor for nodal metastasis among the other risk factors (tumor size, tumor thickness, Clark level and poor differentiation) (p = 0.0021). In combination with tumor thickness >4 mm, tumor budding became a better marker for predicting nodal metastasis (sensitivity 93.3%, specificity 84.7%)., Conclusions: In our cohort, tumor budding was an independent risk factor for nodal metastasis. Our data suggests the promising role of tumor budding in risk evaluation of cutaneous SCC., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Lymphoepithelioma-like carcinoma of the skin (LELCS) is a rare cutaneous neoplasm with histopathologic similarities to nasopharyngeal carcinoma. The association of nasopharyngeal carcinoma with Epstein-Barr virus (EBV) is well documented. EBV has also been reported to be associated with LELC in only four sites (the stomach, salivary glands, lung, and thymus), but not in the skin. We report herein a case of EBV-positive LELCS. An 82-year-old female presented with a red nodule on the right cheek. Histologically, the entire dermis was occupied by atypical tumor cell nests with dense lymphocytic infiltration. Neoplastic cells were strongly positive for cytokeratin 14 but were negative for cytokeratins 19 and 20. EBV genomes in neoplastic cells were detected by polymerase chain reaction analysis and in situ hybridization for EBV-encoded RNA, suggesting an association with EBV., (Copyright 2008 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.)