Hobnail Hemangioma: A Case Report.

Hobnail hemangioma is a small, solitary, benign vascular tumor that shows a biphasic histological pattern of dilated vascular spaces in the superficial dermis and narrow vascular structures in the deeper dermis. In the superficial dermis, dilated, irregular, thin-walled vascular spaces are lined by plump endothelial cells with large nuclei which protrude into the lumina like hobnails. A 43-year-old Japanese man presented with an 11×8-mm bluish-red macule surrounding a 6×3-mm violaceous, slightly elevated papule of the lumbar region of 6 months' duration. Total resection was performed under local anesthesia. Microscopic examination revealed a biphasic pattern with dilated superficial vessels whose endothelial cells were plump with intraluminal papillary projections, showing a "hobnail" appearance, in the papillary layer and upper dermis, and vascular spaces forming slitlike spaces, some of them dissecting collagen fibers, in the deeper dermis. Neither true atypia nor mitotic figures were present. The findings were consistent with those of hobnail hemangioma. Immunohistochemical analysis of the endothelia of the superficial vessels showed that CD31 and D2-40 were expressed, factor VIII was focally expressed, and CD34 and α-SMA were not expressed. In the endothelia of the deeper vessels, CD31, CD34, factor VIII, and α-SMA were expressed, but D2-40 was not expressed. These findings suggest that hobnail hemangioma also shows a biphasic immunohistochemical pattern because of its origin from both lymphatic vessels and blood vessels.

Tenosynovial giant cell tumor arising on the scapular region.

Tenosynovial giant cell tumor (TSGCT) is a benign soft tissue tumor arising from the synovial membrane that composes the lining of joints, tendons and bursae. TSGCT is a common tumor occurring in the hands and fingers, and also consecutively in the knees, ankles, feet and hips. It is rarely found in the scapular region. To the best of our knowledge, only 2 cases arising on the upper back have been reported. This report presents the case of a 44-year-old Japanese female with a TSGCT arising on her right scapular region.

Basal cell carcinoma arising on a chronic lymphedematous leg.

We describe a case of an 82-year-old Japanese woman with basal cell carcinoma (BCC) on the leg with secondary chronic lymphedema due to treatment for uterine cancer. Sparse tumor nests with remarkable edema of the dermis in the nodule appeared to be influenced by the chronic lymphedema. However, it remains inconclusive whether or not the tumorigenesis of the BCC was associated with chronic lymphedema in this case.

Mediastinal lymph node metastasis of lung cancer with an unknown primary lesion having concurrent endocrine abnormality and acanthosis nigricans: report of a case.

We herein describe a patient we encountered in whom mediastinal lymph node metastasis of lung cancer with an unknown primary lesion was complicated by both an endocrine abnormality and acanthosis nigricans. A 66-year-old male visited a local hospital and was diagnosed as having acanthosis nigricans. The patient was referred to our hospital for further examination. Computed tomography scans of the chest and the abdomen showed no adverse findings except for an enlargement of the mediastinal lymph node. No malignant lesions were detected in examinations of the upper gastrointestinal tract. Based on the above findings, the lesion was thus considered to possibly be mediastinal lymph node metastasis of an unknown primary tumor or malignant lymphoma. A thoracoscopic biopsy of the mediastinal lymph node was performed. The patient was diagnosed to have mediastinal lymph node metastasis of lung cancer with an unknown primary lesion and endocrine abnormality resulting from paraneoplastic syndrome. Palliative radiation therapy was initiated to prevent superior vena cava syndrome and esophageal passage failure or dysphagia. The cutaneous lesions markedly improved thereafter. The serum levels of adrenocorticotropic hormone decreased.

Case of Sweet's syndrome with extensive necrosis and ulcers accompanied by myelodysplastic syndrome.

A 43-year-old woman presented with a persistent high fever of 39 degrees C and edematous erythema accompanied by pustules on the face, trunk and extremities. Conjunctivitis and nodules were also observed in the right eye. On the basis of the clinical symptoms and histopathological findings. Sweet's syndrome was diagnosed. Eruptions quickly progressed to extensive necrosis and ulcers, mimicking clinical features of pyoderma gangrenosum. A bone marrow biopsy indicated myelodysplastic syndrome. Oral administration of 50 mg/day of prednisolone induced epithelialization of ulcers, with remaining scarring and pigmentation. Six months later, myelodysplastic syndrome had progressed to acute myelogenous leukemia.

A case of peripheral T-cell lymphoma unspecified involving subcutaneous tissue.

A 36-year-old man presented with a 3-year-old red-brown plaque with subcutaneous nodules on his left thigh. Although a similar lesion was observed on his right thigh 3 years earlier, it spontaneously disappeared 1 year later. However, the lesion on the left thigh was growing larger. Histologically, the lesion showed a diffuse and dense infiltration of atypical lymphocytes extending from the superficial dermis to the subcutaneous tissue. Severe lobular panniculitis, composed of small- and medium-sized atypical lymphocytes and large normal histiocytes, was observed in the subcutaneous adipose tissue. Immunohistochemical studies revealed a post-thymic T-cell phenotype. A genetic analysis demonstrated a rearrangement of the T-cell receptor chain gene. The left skin lesion also gradually disappeared after skin biopsy without therapy, and he continues to be in remission.

Wound healing involves induction of cyclooxygenase-2 expression in rat skin.

Cyclooxygenase (COX), an enzyme essential for prostaglandin biosynthesis, has two isoforms, COX-1 and -2. We investigated temporal and spatial changes in localization of these two COX proteins and mRNAs after excisional injury in rat skin. We also quantified the expression of these proteins and studied the effects of a specific COX-2 inhibitor on healing. Immunohistochemistry and in situ hybridization respectively indicated that the COX-2 protein and mRNA were expressed mainly within the basal layer of the epidermis, peripheral cells in the outer root sheath of hair follicles, and fibroblast-like cells and capillaries near epidermal wound edges. Much less intense expression was observed in normal skin than in injured skin. Western analysis demonstrated marked induction of COX-2 protein beginning within 12 hours and peaking 3 days after injury. In contrast, localization of COX-1 protein and mRNA, as well as the amount of protein expression, showed no significant change during wound healing. Administration of the COX-2 inhibitor delayed re-epithelialization in the early phase of wound healing and also inhibited angiogenesis. Thus, COX-2 induction may be important in cutaneous wound healing.