Basal Cell Carcinoma with Spontaneous Regression: A Case Report and Immunohistochemical Study

Spontaneous regression of basal cell carcinoma (BCC) is rare, and characterized by various tumor-infiltrating lymphocytes (TILs) in the tumor. A previous report suggested that these infiltrated lymphocytes consist of type 1 helper T cells, but no detailed phenotypical analysis of other TILs has been demonstrated yet. In this report, we describe an 84-year-old Japanese patient with spontaneous regression of BCC. In the present case, we investigated the immunohistochemical profiles of TILs, not only focusing on the cytotoxic T cells, but the profiles of immunosuppressive cells, such as regulatory T cells and tumor-associated macrophages. Our present study sheds light on the immunological mechanisms of tumor rejection in human BCC

Identification of mutations through dominant screening for obesity using C57BL/6 substrains

The discovery of leptin substantiated the usefulness of a forward genetic approach in elucidating the molecular network regulating energy metabolism. However, no successful dominant screening for obesity has been reported, which may be due to the influence of quantitative trait loci between the screening and counter strains and the low fertility of obese mice. Here, we performed a dominant screening for obesity using C57BL/6 substrains, C57BL/6J and C57BL/6N, with the routine use of in vitro fertilization. The screening of more than 5000 mutagenized mice established two obese pedigrees in which single nucleotide substitutions in Mc4r and Sim1 genes were identified through whole-exome sequencing. The mutation in the Mc4r gene produces a premature stop codon, and the mutant SIM1 protein lacks transcriptional activity, showing that the haploinsufficiency of SIM1 and MC4R results in obesity. We further examined the hypothalamic neuropeptide expressions in the mutant pedigrees and mice with diet-induced obesity, which showed that each obesity mouse model has distinct neuropeptide expression profiles. This forward genetic screening scheme is useful and applicable to any research field in which mouse models work

RANKL-Expressing Ectopic Extramammary Paget’s Disease on the Lower Abdomen

Ectopic extramammary Paget’s disease (EMPD) is a rare variant of EMPD that develops in nonapocrine regions. Since reports about ectopic EMPD are limited, little is known about the biological and immunological background of ectopic EMPD. In this report, we present a case of ectopic EMPD on the lower abdomen that expressed RANKL but lacked the expression of MMP7. As we previously reported, Paget’s cells express RANKL and MMP7, release soluble RANKL in the tumor microenvironment, and stimulate tumor-associated macrophages to produce tumor-loading factors in conventional EMPD. In our present case, both CCL5-expressing cells and MMP25-bearing cells were lacking, whereas substantial numbers of CCL5-expressing cells and MMP25-bearing cells were found in conventional EMPD. Our case suggested that the lack of MMP7 on Paget’s cells might be one of the possible explanations for the biology of ectopic EMPD

Immunohistochemical Similarities between Lichen Sclerosus et Atrophicus and Morphea: A Case Study

Both morphea and lichen sclerosus et atrophicus (LSA) are connective tissue diseases that mainly affect the skin. A recent report suggested that a substantial portion of morphea coexists with LSA. In this report, we describe a case of LSA on the abdomen accompanied by morphea; we employed immunohistochemical staining for periostin as well as MMP-7 and MMP-28, both of which are reported to facilitate fibrosis in the development of various organs, including skin. To our knowledge, this is first English language paper that demonstrates the immunohistochemical staining of periostin, MMP-7 and MMP-28 for morphea and LSA. Our present case might suggest possible mechanisms for the coexistence of two different sclerotic skin disorders

Bullous Pemphigoid Accompanied by Aplastic Anemia: The Induction of IL-17-Producing Cells in the Affected Areas of the Skin

Th17 cells, characterized by IL-17 production, play a critical role in the pathogenesis of autoimmune diseases, including autoimmune bullous disorders and aplastic anemia (AA). In this report, we describe a 58-year-old Japanese man with bullous pemphigoid (BP) accompanied by AA. Interestingly, immunohistochemical staining revealed the existence of IL-17-producing cells in the skin biopsy specimens from BP. Our findings might suggest relationships between IL-17 and the pathogenesis of these autoimmune diseases, and, to our knowledge, this is the first English report of BP accompanied by AA

Successful Treatment of Adult-Onset Erythromelalgia with Steroid Pulse and Pregabalin

Adult-onset erythromelalgia (EM) is a rare disease characterized by episodic bouts of burning pain and erythema for which the optimal therapy is unclear. In this report, we describe a 68-year-old Japanese woman with adult-onset EM. Intravenous administration of methylprednisolone sodium succinate 1,000 mg/day dramatically improved her pain as evaluated by the visual analog scale. Although the patient’s pain gradually developed again, it could be controlled with pregabalin. Our present case might suggest a possible, optimal therapy for adult-onset EM

Pseudolymphomatous Folliculitis on the Nose

Pseudolymphomatous folliculitis (PLF), which sometimes mimicks cutaneous lymphoma, is a rare manifestation of cutaneous pseudolymphoma and cutaneous lymphoid hyperplasia. We describe a 57-year-old Japanese woman with PLF on the nose that resembled cutaneous lymphoma clinically. The biopsy specimen revealed dense lymphocytes, especially CD1a+ cells, infiltrated around the hair follicles. Without any additional treatment, her nodule rapidly decreased before we performed a second biopsy for analysis of the clonal gene rearrangement. Though PLF typically behaves as benign lymphohyperplasia, differentiation from cutaneous lymphoma is necessary

Merkel Cell Carcinoma with Spontaneous Regression: A Case Report and Immunohistochemical Study

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine carcinoma that only rarely regresses spontaneously. Since little is known about the immunological mechanisms involved in the spontaneous regression of MCC, we describe a case of MCC with spontaneous regression and employed immunohistochemical staining for cytotoxic and immunosuppressive molecules to investigate possible mechanisms involved in the spontaneous regression of MCC. Interestingly, compared to conventional MCC, tumor-infiltrating lymphocytes in MCC with spontaneous regression contained higher numbers of CD8+ cells and granulysin-bearing cells and lower numbers of CD206+ cells. Our present study suggests one of the possible reasons for the spontaneous regression of MCC