Pseudoprogression is an atypical response after cancer treatment, and is defined as a temporary increase in the total tumor burden. Previously, pseudoprogression has often been reported after combination treatment of chemotherapy and radiotherapy, but recently, it has been reported after immune checkpoint blockade therapy, such as after treatment with the PD-1 inhibitor nivolumab. Pseudoprogression is shown as nodules on computed tomography (CT) imaging, which indicates T cell infiltration and extensive necrosis. In our study, we explored pseudoprogression in 8 malignant melanoma patients using ¹⁸F-FDG PET/CT imaging in our department.[Skin Cancer (Japan) 2016 ; 31 : 110-113]

A 48-year-old male patient with a congenital melanocytic nevus (CMN) noticed a tumor near the CMN one year prior to his first visit to our clinic. Topical therapies were ineffective in treating the tumor, and he began to experience disturbances in consciousness. During his first visit, a CMN with a diameter of 20 cm was observed on the back of his head. An 8-cm skin tumor and a 6-cm subcutaneous tumor were noted adjacent to the CMN. Biopsy examination of the skin tumor confirmed malignant melanoma. Magnetic resonance imaging was suggestive of frontal lobe metastases, which was confirmed on histopathology examination. Surgical removal of the melanoma was performed, during which no continuity with the CMN was observed. Postoperatively, he was administered nivolumab and underwent radiation therapy including CyberKnife robotic radiosurgery for the brain metastases. However, the tumor continued to increase in size. The patient had progressive disease and died four months later.[Skin Cancer (Japan) 2016 ; 31 : 114-117]

A 75-year-old woman with subcutaneous chest nodules visited our department. The nodules, which had developed two months previously, increased gradually and spread throughout the body. Hen's egg-sized red tumors were noted in the chest midline, with many thumb-sized normal colored or red subcutaneous nodules in the trunk, upper arms, and thighs. Neither lymph node enlargement nor internal organ lesions were detected on computed tomography. Histopathologically, large atypical lymphocytes were infiltrated in a nodular manner from the superficial dermis to the subcutaneous tissue. Immunohistochemically, CD20, CD79a, CD10, BCL6, BCL2, MUM1, and CD5 were all positive. Thus, a diagnosis of CD5-positive cutaneous diffuse large B-cell lymphoma (CD5+DLBCL) was established, and the patient underwent eight courses of R-THP-COP therapy, without recurrence or metastasis. In this paper, we perform a literature review of CD5+DLBCL, a relatively rare lymphoma associated with marked recurrence in the central nervous system and a poor prognosis.[Skin Cancer (Japan) 2016 ; 31 : 118-122]

We studied five melanoma patients with BRAF gene mutations, who had been treated with vemurafenib at our department from March 2015 to May 2016. The patients comprised three men and two women, with an age range of 50 to 62 years and a mean age of 56.2 ± 4.6 years. The clinical subtypes included four cases of superficial spreading melanomas (SSM) and one of acral lentiginous melanoma (ALM). Treatment with vemurafenib resulted in one case of complete remission, two of stable disease, and two of treatment cessation. The patients experienced several adverse effects such as prolonged corrected QT intervals, drug eruptions, and hypokalemia. Based on the experiences of the patients with severe adverse effects, we concluded that previous therapy involving immune checkpoint inhibitors may play a role in inducing severe drug eruptions, and that the combination of vemurafenib and moderate-to-high dose steroids may result in immunocompromise.[Skin Cancer (Japan) 2016 ; 32 : 123-127]

A 79-year-old woman presented with a 3-month history of vulval discomfort and experienced vulval erythema of increasing severity. An initial physical examination revealed erythema and red nodules on the labia minora, along with skin atrophy and depigmentation. The histopathological examination showed acanthosis with atypical keratinocytes at all levels of the epidermis with multinucleated giant cells, dyskeratotic cells, and mitoses. Therefore, we diagnosed this condition as erythroplasia of Queyrat. We performed resection with a 5-mm surgical margin from the erythema. Human papillomavirus (HPV) DNA testing was performed using a polymerase chain reaction method, and HPV type 58 DNA was identified. We thus describe a case of HPV-58 positive erythroplasia of Queyrat.[Skin Cancer (Japan) 2016 ; 31 : 128-132]

A 62-year-old man presented with an 18 × 11-cm tumor in the posterior femoral region. A diagnosis of squamous cell carcinoma was made on the basis of the pathological findings. Whole body examination, including computed tomography (CT), demonstrated swollen inguinal lymph nodes, although no evidence of distant metastasis was found. We administered a chemotherapy regimen with 5-fluorouracil and cisplatin as neoadjuvant agents. After chemotherapy, a decrease in the size of the tumor was observed and we performed resection of the primary lesion and the swollen inguinal lymph nodes. No tumor cells were observed in the surgical margins or the lymph nodes. Wound dehiscence occurred 7 days after surgery, which required prolonged bed rest. Twenty days after surgery, owing to elevated serum C-reactive protein and D-dimer levels, we performed contrast-enhanced CT, and a bilateral pulmonary embolism (PE) was diagnosed. Anticoagulant therapy was initiated promptly, and the patient was discharged from the hospital 41 days after the surgery. PE is an important and potentially fatal perioperative complication and should always be considered even after the dermatological surgery.[Skin Cancer (Japan) 2016 ; 31 : 133-138]

A 74-year-old woman presented with a grey lesion on her right big toe. She underwent an excisional biopsy of the lesion at another hospital. Histologically, it was diagnosed as a malignant melanoma ; the tumor thickness was 1.9 mm. The lesion was resected with 2-cm margins, which resulted in MP joint amputation. However, pathology revealed positive surgical margins. Punch biopsies were performed at sites 1 to 2 cm from the prior positive margins to confirm the border of the tumor. The results showed no residual melanoma cells. Therefore, an additional surgical resection was performed with 1-cm margins. However, the pathology revealed positive surgical margins again. The patient underwent an initial surgical excision, followed by 3 subsequent excisions until a pathologically negative margin was obtained. It was difficult to confirm the border of the tumor because of the absence of melanin pigmentation.[Skin Cancer (Japan) 2016 ; 32 : 139-143]

A 61-year-old man noticed an erythematous tumor with blood crusting on his genital area in January 2014. However, he had not undergone any medical care for the lesion for 8 months after noticing it. On the first examination, the tumor measured 25×20 mm and he had several swollen lymph nodes on both sides of the groin areas. A histological examination revealed adenocarcinoma composed of atypical cells with abundant eosinophilic cytoplasm and a decapitation in some parts of the tumor. The tumor cells were positive for GCDFP-15, CEA, ER, and PgR. No evidence of metastasis to other organs was observed. Based on these findings, the tumor was diagnosed as an apocrine carcinoma. It was broadly excised, and total superficial inguinal lymphadenectomy was performed. At present, 17 months after surgery, no recurrence has been noted.[Skin Cancer (Japan) 2016 ; 31 : 144-149]

The first patient was a 43-year-old man with a slightly elevated macule on his right chest that was first noted 5 years previously. A pinkish brown atrophic macule, 12×5 mm in size, with an elastic hard induration underneath the macule was observed. The second patient was a 79-year-old woman with a macule on her left breast since 50 years. The lateral part of the macule started protruding as a nodule a few months ago. Physical examination revealed a pinkish brown atrophic macule, 30×10 mm in size. The nodule on the macule was firm and 10 mm in size. An elastic hard induration was palpable underneath the macule. Histopathologically, both cases showed that spindle-shaped cells with chromatin-rich-nuclei were infiltrating from the dermis to the adipose layer, forming a storiform pattern. Those cells were CD34 positive. In the first case, the lesion was surgically removed with a 30-mm border, resulting in a negative surgical margin. In the second case, no additional resection after excisional biopsy was performed owing to the negative margin. There was no evidence of recurrence during the 10 years and 1.5 years of follow-up, respectively.[Skin Cancer (Japan) 2016 ; 31 : 150-155]

A 42-year-old woman noticed enlargement of a black macule on her back that had been present for over 20 years. We observed an asymmetric but well-defined macule, measuring 11× 7 mm, showing multiple shades of brown-black colors with a nodule on the upper side. Dermoscopic examination revealed irregular blotch with blue-whitish veil in the lower side of the lesion, atypical pigment network at the periphery of the entire lesion, and hypopigmented structureless area in the upper side nodule. Histopathologically, proliferation of atypical melanocytes positive for S-100 and HMB-45 stain was detected mainly in the epidermis and partly in the dermis of the lesion. However, in the nodule of the lesion, dermal nests of nevus cells negative for HMB-45 stain could be detected around appendix. We diagnosed malignant melanoma colliding with intradermal nevus although verifying whether the nevus was the origin of the melanoma was difficult.[Skin Cancer (Japan) 2016 ; 31 : 156-161]

A 59-year-old man presented with a 5-year history of an erythematous plaque and nodule on the groin and scrotum. Biopsy results confirmed the diagnosis of extramammary Paget's disease. A wide surgical excision was made and sentinel lymph node biopsy (SLN) was performed. Upon confirming tumor cell involvement on SLN, right inguinal lymph node dissection was performed. Five months thereafter, positron emission tomography-computed tomography revealed multiple lymph node metastases. We performed chemotherapy sensitivity test by using the histoculture drug response assay (HDRA). The tumor growth inhibition rates were found to be higher with irinotecan (CPT-11) and mitomycin C (MMC). After 3 cycles of combined therapy with CPT-11 and MMC, remission of multiple metastases was achieved. Follow-up over a period of 5 months after therapy with additional 4 cycles showed complete remission. However, the patient developed multiple lung metastases and died 31 months postoperatively. HDRA may be useful to evaluate the antitumor effects of chemotherapy, but further examination is necessary to monitor recurrence and prognostic improvement.[Skin Cancer (Japan) 2016 ; 31 : 162-167]

A 46-year-old man presented with a 1-year history of a gradually enlarging solid tumor on his left auricle, which was dark red with surface telangiectasias and crusts. Histopathology revealed that nests of adenocarcinoma cells were floating in mucinous cystic lesions located in the dermis. The tumor cells were immunohistochemically positive for CK7, CK20, and GCDFP-15. The patient was diagnosed with a primary cutaneous mucinous carcinoma (PCMC) on the basis of the histologic and systemic examination findings. Surgical excision and auricular plasty were performed. Although PCMC on the auricle is very rare, PCMC should be considered among the differential diagnoses of a nodule on the craniofacial region.[Skin Cancer (Japan) 2016 ; 31 : 168-172]

An 86-year-old woman with bladder cancer (T2N0M0, G3) underwent transurethral resection of a bladder tumor three times, a year ago. She had noticed an induration in the right inguinal area, which gradually enlarged to the abdomen and right thigh and formed into a board-like induration over 3 months. Dermoscopic examination showed a pinkish background with serpentine and linear vessels, which were compatible with findings of a metastatic carcinoma of the skin. Histological examination revealed diffuse proliferation of the tumor cells in the dermis to the subcutaneous tissue with a focal Indian filing appearance. A diagnosis of sclerodermoid type metastasis (cancer en cuirasse) from bladder cancer was established. A literature review from 1983 to 2015 in Japan demonstrated that 2 of 51 (4%) cases were the sclerodermoid type. Because all the cases of the sclerodermoid and inflammatory types had lymph node metastasis and the lesions were mainly limited to the lower abdomen, these types are thought to occur as a result of retrograde flow from lymphatic metastasis.[Skin Cancer (Japan) 2016 ; 31 : 173-178]

A 58-year-old man with a diagnosis of atopic dermatitis from his childhood was treated with topical steroids and systemic antihistamine. Despite the extensive duration of this treatment, the state of the rash worsened. Owing to poor disease control, the patient had been treated with low-dose cyclosporine (200 mg/day) since 2008, which resulted in temporary improvements. He developed erythroderma featuring palpable axillary and inguinal lymph nodes, which were accompanied by a steady increase in the count of atypical lymphocytes (20%) and level of interleukin-2R (7,765 U/mL). There was no pathological presence of atypical lymphocytes. T cell receptor rearrangement revealed monoclonality in the blood, indicative of a diagnosis of atopic dermatitis-like pre-Sézary syndrome. Cyclosporine treatment was discontinued and the patient was treated using extracorporeal photopheresis and systemic steroids. At present, the skin of the patient has improved.[Skin Cancer (Japan) 2016 ; 31 : 179-183]

A 72-year-old woman detected a gradually enlarging mass in her left vulva 1 year before. Based on the result of a skin biopsy performed at another hospital, she was diagnosed as having extramammary Paget's disease and referred to our hospital. Physical examinations revealed an 8- × 4-cm tumor on her left vulva, with erythematous lesions. Computed tomography revealed distal metastasis to the bilateral inguinal, left iliac, para-aortic, and left supraclavicular lymph nodes. She received nine cycles of monthly docetaxel therapy and seven cycles of S-1 therapy. Although these therapies led to partial remission, the disease progressed to an advanced stage and was complicated by bilateral hydronephrosis and obstructive jaundice. Direct invasion from the vulva to a retroperitoneal organ was confirmed by using contrast-enhanced computed tomography. She died from the disease 24 months after the initial therapy.[Skin Cancer (Japan) 2016 ; 31 : 184-188]