A case of overlapping adult-onset linear scleroderma and Parry-Romberg syndrome presenting with widespread ipsilateral neurogenic involvement.

Linear scleroderma is a variant of localized scleroderma. We report a 43-year-old woman who had developed left arm weakness and linear scleroderma on her back during pregnancy at 25 years of age, followed by left hemifacial atrophy and left leg weakness. She had multiple linear scleroderma lesions on her trunk and left limbs, left eyelid ptosis, impairment of vertical movement and abduction of the left eye, left hemifacial atrophy, and weakness and atrophy of the sternocleidomastoid, trapezius, and proximal limb muscles on the left side. On serology, antibodies to U1-ribonucleoprotein and Jo-1 were positive; anti-scleroderma-70 antibody was negative. Skin biopsy demonstrated increased hypertrophic collagen fibers without inflammatory infiltrates. Needle electromyography of left limb muscles revealed mild neurogenic patterns; left quadriceps muscle biopsy showed chronic neurogenic changes. Brain magnetic resonance imaging revealed mild left hemispheric atrophy. This is a rare case of linear scleroderma and Parry-Romberg syndrome presenting with widespread ipsilateral neurogenic manifestations.

Intra- and Inter-Tumor BRAF Heterogeneity in Acral Melanoma: An Immunohistochemical Analysis.

The current development of BRAF inhibitors has revolutionized the treatment of unresectable melanoma. As the potential heterogeneity of BRAF mutations in melanoma has been reported, accurate detection of BRAF mutations are important. However, the genetic heterogeneity of acral melanoma-a distinct type of melanoma with a unique genetic background-has not fully been investigated. We conducted a retrospective review of our acral melanoma patients. Of the 196 patients with acral melanoma, we retrieved 31 pairs of primary and matched metastatic melanomas. We immunostained the 31 pairs with VE1, a BRAFV600E-mutation-specific monoclonal antibody. Immunohistochemistry with VE1 showed a high degree of sensitivity and specificity for detecting BRAFV600E mutations compared with the real-time polymerase chain reaction method. A total of nine primary (29.0%) and eight metastatic (25.8%) acral melanomas were positive for VE1. In three patients (9.7%), we observed a discordance of VE1 staining between the primary and metastatic lesions. Of note, VE1 immunohistochemical staining revealed a remarkable degree of intra-tumor genetic heterogeneity in acral melanoma. Our study reveals that VE1 immunostaining is a useful ancillary method for detecting BRAFV600E mutations in acral melanoma and allows for a clear visualization of intra- and inter-tumor BRAF heterogeneity.

Histopathological and genetic review of phosphaturic mesenchymal tumours, mixed connective tissue variant.

AIMS: Phosphaturic mesenchymal tumour, mixed connective tissue variant (PMT-MCT), is a tumour of uncertain differentiation, characterised by 'smudgy/grungy' calcification and vitamin D-resistant phosphaturic osteomalacia. Fibroblast growth factor (FGF)23 is recognised as a reliable marker of PMT-MCT, but quantitative evaluation has never been performed. We reviewed cases of tumour-associated osteomalacia or histologically definitive PMT-MCT without osteomalacia using histological, immunohistochemical and genetic methods and evaluated the diagnostic significance of these findings. METHODS AND RESULTS: A total of 19 tumours from 14 cases diagnosed previously as PMT-MCT were retrieved, on which immunohistochemical staining, reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence in-situ hybridisation (FISH) analysis were performed. Histologically, fibrous capsule, calcification and giant cell reaction tended to be observed in soft-tissue PMT-MCT, while PMT-MCT of bone and multiple PMT-MCT showed an infiltrative growth pattern. The immunohistochemical results were as follows: the tumour cells were positive for FGF23 (nine of 12, 75%), FGFR1 (11 of 11, 100%), CD56 (12 of 14, 85.7%) and E26 oncogene homologue (ERG) (5 of 13, 38.4%). The sole malignant tumour was positive for p53. FGF23 mRNA was detected in seven of 14 formalin-fixed paraffin-embedded (FFPE) specimens and all five frozen specimens by RT-PCR. The level of FGF23 mRNA, which was determined by real-time PCR, varied among the phosphaturic cases. Two of 17 tumours were positive for FGFR1 gene rearrangement. CONCLUSIONS: It was considered that PMT-MCT is a histopathological entity with or without phosphaturia, with varying levels of FGF23 mRNA, and with or without fibronectin 1 (FN1)-FGFR1 fusion gene. The authors propose that the histology of PMT-MCT differs depending on its location, such as bone or soft tissue, which could complicate the differential diagnosis.

Preferential expression of OVOL1 in inner root sheath of hair, sebaceous gland, eccrine duct and their neoplasms in human skin.

OVOL1 is an important transcription factor for epidermal keratinization, which suppresses proliferation and switches on the differentiation of keratinocytes. A recent genome-wide association study has revealed that OVOL1 is one of the genes associated with susceptibility to atopic dermatitis. Although it is known to be expressed in murine skin and hair follicles, no investigations have focused on its localization in human skin. In the present study, we thus immunolocalized the expression of OVOL1 in normal and diseased human skin. In normal human skin, OVOL1 was preferentially expressed in the suprabasal layer of the epidermis, inner root sheath of hair, mature sebocytes and the ductal portion of the eccrine glands. Compared to this, no remarkable change in the expression of OVOL1 was observed among inflammatory skin diseases. The expression of OVOL1 was evident in eccrine poroma and hidradenoma. Moreover, it was overexpressed in Bowen's disease and sebaceous adenoma, in sharp contrast to its downregulation in their more malignant counterparts, squamous cell carcinoma and sebaceous carcinoma. OVOL1 may play an important role in human skin morphogenesis and tumorigenesis.

Histological background of dedifferentiated solitary fibrous tumour.

AIMS: Dedifferentiation is a histological phenomenon characterised by abrupt transition of histology to a sarcomatous component with high-grade malignant potential in solitary fibrous tumour (SFT). The authors histologically reviewed SFT cases to reveal the histological background of dedifferentiated SFTs. METHODS: Clinicopathological and histopathological findings of 145 SFT cases were reviewed. Immunohistochemical staining and genetic analysis were also performed. RESULTS: The non-dedifferentiated components showed a cellular component in 45 of 145 (31%), high mitotic rate (≥4/10 high-powered field) in 12 of 145 (8.2%) tumours, necrosis in 7 of 145 (4.8%) tumours, multinodular growth pattern in 39 of 132 (29.5%) available tumours and intratumoural fibrous septa in 37 of 131 (28.2%). Immunohistochemically, the non-dedifferentiated components were positive for CD34 in 128 of 141 (90.7%), bcl-2 in 101 of 133 (75.9%), nuclear pattern of ß-catenin in 64 of 127 (50.3%) and p16 in 22 of 140 (15.7%). Loss of Rb protein expression was detected in 17 of 110 (15.4%) cases. Statistically, cellular component, multinodular structure, p16 overexpression and Rb protein loss were significantly associated with dedifferentiation. Moreover, cellular component and multinodular structure were significantly associated with p16 overexpression and Rb protein loss. All the non-deddifferentiated components showed wild type of p53 expression. The dedifferentiated components of all 10 dedifferentiated tumours presented positivity for p16 in 9 of 10 (90%) and mutational type of p53 in 5 of 10 (50%). Loss of Rb protein expression was detected in 6 of 10 (60%). CONCLUSIONS: The authors propose that cellular or multinodular transformation may be associated with dedifferentiation. They also suggest that cellular and multinodular transformation may be associated with p16 overexpression and Rb downregulation.

A novel fusion gene CRTC3-MAML2 in hidradenoma: histopathological significance.

Hidradenoma usually presents as a solitary, slow-growing, and solid or cystic nodular lesion, which arises in various anatomical sites. Its diagnosis is occasionally difficult because the tumor shares histological features with other cutaneous appendage tumors. Recently, CRTC1-MAML2 fusion gene was reported in hidradenomas, with the fusion transcript being demonstrated in approximately 50% of cases. However, limited information is available regarding its clinical significance. Here, we investigated the relationship between the fusion gene and clinicohistopathological features. We reviewed 39 cases histologically diagnosed as hidradenoma. Reverse-transcription polymerase chain reaction (RT-PCR) was performed for all 39 cases, and fluorescence in situ hybridization was also performed for the RT-PCR-negative cases. The 39 tumors included 36 clear cell hidradenomas and 3 poroid hidradenomas. The details of the cellular components were as follows: clear cell-dominant type, 9 cases; polygonal cell-dominant type, 21 cases; and equally mixed type, 9 cases. There were no tumors with apparent mucinous cells. There were 8 tumors with prominent cystic change, 2 of which presented apocrine-like decapitated secretion. CRTC1-MAML2 fusion was detected in 10 of the 39 tumors (26%) and CRTC3-MAML2 fusion in 2 of the 39 (5%) by RT-PCR. MAML2 gene rearrangement was detected in 11 of 27 fusion gene-negative cases by fluorescence in situ hybridization. Moreover, neither the fusion genes nor gene rearrangement was detected in prominent cystic tumors and poroid hidradenomas. We conclude that CRTC1/3-MAML2 fusion gene analysis can be a useful method for diagnosing hidradenoma. Considering the histological and genetic similarity to mucoepidermoid carcinoma, hidradenoma may be a cutaneous counterpart of salivary gland mucoepidermoid carcinoma.

HIF-1α, MDM2, CDK4, and p16 expression in ischemic fasciitis, focusing on its ischemic condition.

Ischemic fasciitis is a benign myofibroblastic lesion, occurring in the sacral region or proximal thigh of elderly or bedridden individuals. The pathogenesis of ischemic fasciitis is thought to be based on ischemic condition; however, it has never been demonstrated. In this study, we examined the expression of ischemia-associated proteins in ischemic fasciitis by immunohistochemical and genetic methods. Specifically, this study aimed to reveal the expression of HIF-1α, MDM2, CDK4, p16, and gene amplification of MDM2 gene. Seven cases of ischemic fasciitis from among the soft-tissue tumors registered at our institution were retrieved. Histopathological findings were as follows: poorly demarcated nodular masses, a proliferation of spindle-shaped fibroblastic or myofibroblastic cells with oval nuclei and eosinophilic or pale cytoplasm, zonal fibrinous deposition, pseudocystic degeneration, granulation-like proliferation of capillary vessels, ganglion-like cells, myxoid or hyalinized stroma, and chronic inflammatory infiltration. Immunohistochemically, the spindle cells were positive for HIF-1α (7/7 cases), MDM2 (4/7 cases), CDK4 (4/7 cases), p16 (7/7 cases), p53 (2/7 case), cyclin D1 (7/7 cases), and alpha-smooth muscle actin (6/7 cases). Neither MDM2 gene amplification nor USP6 gene split signal was detected in any case. Overexpression of the above proteins may be associated with the pathogenic mechanism of ischemic fasciitis. It is noted that the immunohistochemical positivity of MDM2, CDK4, and p16 do not necessarily indicate malignant neoplasm such as dedifferentiated liposarcoma.

Two Cases of Cutaneous Squamous Cell Carcinoma Arising in Immunosuppressed Patients with Chronic Human Papillomavirus Infection.

Increasing evidence has suggested that human papillomaviruses (HPVs) are linked to a large subset of numerous malignant tumors, including mucosal squamous cell carcinoma (SCC); however, its involvement in cutaneous SCC has not fully been elucidated. Cutaneous SCC is the second most common type of skin cancer and is increasing in frequency every year. Since we have no satisfactory treatment for advanced SCC, it is important to provide a definitive diagnosis and appropriate therapeutic intervention at an early stage. Here, we present two cases of SCC arising in immunosuppressed patients. In these cases, we suspected the association between SCC and HPV infection histopathologically and succeeded in proving the presence of high-risk type HPV by PCR analysis (HPV 14 in case 1 and HPV 23 and 38 in case 2). Although it is unclear whether HPV actually induced SCC in our cases, our cases showed rapid progression comparing to typical courses of actinic keratosis (AK)/SCC. SCC and AK are common diseases; in daily practice, dermatologists examine many patients with immunosuppression of various causes. We should apply increased oncological vigilance to these patients to prevent an aggressive course of SCC/AK.