Lymphoproliferative Disorder in an Esophageal Cancer Patient Treated with Pembrolizumab.

A 75-year-old man diagnosed with esophageal cancer and lung metastasis received a combination of fluorouracil, cisplatin, and pembrolizumab. During pembrolizumab maintenance therapy, lymphoproliferative lesions at the lips and mouth and multiple lymph node swellings appeared. Histologically, Epstein-Barr virus (EBV)-encoded RNA was positive, and EBV-DNA was detected in the blood.

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.

Intra- and Inter-Tumor 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 mutations in melanoma has been reported, accurate detection of 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.

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.

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.

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.

Alteration of PDGFRβ-Akt-mTOR pathway signaling in fibrosarcomatous transformation of dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous mesenchymal tumor of intermediate malignancy and fibroblastic/myofibroblastic differentiation. Fibrosarcomatous (FS) component is a high-grade component of DFSP. The detailed oncogenic difference between DFSP and FS components is not clear.

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.

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.

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.