Kiyofumi Egawa

Do Human Papillomaviruses Target Epidermal Stem Cells

Little is known about the target cells of human papillomaviruses (HPVs). The clinical and histological analyses of very early lesions of palmoplantar warts indicate that not only the warts initially developed exclusively in the ridges of the skin, but also that the initial histological changes were restricted to the deep ridges of the epidermis, where epidermal stem cells are thought to exist in the palmoplantar skin. This suggests that HPV infection targets the stem cells.

New types of human papillomaviruses and intracytoplasmic inclusion bodies: a classification of inclusion warts according to clinical features, histology and associated HPV types

Summary Two new types of intracytoplasmic inclusion bodies (ICBs) associated with distinct clinical features, and the presence of DNA of distinct types of human papillomaviruses (HPVs) are reported. One hundred and seven cutaneous warts containing ICBs were grouped into three categories according to distinct clinicopathological features: 67 were wart lesions with well‐known granular (Gr)‐ICB. 1 3 were punctate keratotic lesions with filamentous (Fl)‐ICB and 31 were pigmented warts with homogeneous (Hg)‐ICB. Molecular biological studies were performed in order to assess a specific association of each group of warts with distinct types of HPV.

Pigmented viral warts: a clinical and histopathological study including human papillomavirus typing

Although clinical, histological and viral correlations have recently been established among pigmented warts, homogeneous intracytoplasmic inclusion bodies and related types of human papillomavirus (HPV) (HPV 65, 4 and 60), the causes of the pigmentation remain unknown. In this study, comparative histological and histochemical analyses were performed with 53 pigmented (34 HPV 65‐induced, 12 HPV 4‐induced and seven HPV 60‐induced) and 73 non‐pigmented warts (27 HPV 2‐induced, 23 HPV 1‐induced, 12 HPV 63‐induced, six unknown HPV‐type induced and five HPV 60 induced) to clarify the causes of the pigmentation. Electron microscopy was also used to examine the pigmented warts. Many melanin blockade melanocytes were identified in all of the pigmented warts with Masson–Fontana staining and electron microscopy, and increased melanin in keratinocytes was also noted in 22 pigmented warts, suggesting that the dispersion of melanin granules in the dendrites of the melanin blockade melanocytes and the increased melanin granules in keratinocytes are the primary contributors to the pigmentation of the warts.

Detection of human papillomaviruses and eccrine ducts in palmoplantar epidermoid cysts

Summary Although epidermoid cysts of the palms and soles have long been assumed to develop following implantation of an epidermal fragment as a result of a penetrating injury, the pathogenic mechanism is still controversial, and the discovery of a more common aetiological agent is awaited. Clinical, histological, immunohistochemical and molecular biological studies were performed on 119 epidermoid cysts of palmoplatitur location, in order to examine the rote of the eccrine ducts, and human papillomavirus (HPV), in the pathogenesis of this disorder.

Human papillomavirus 57 identified in a plantar epidermoid cyst

We report a 23‐year‐old Japanese man who had plantar warts on the right sole, beneath one of which an epidermoid cyst developed. On microscopic examination, an acanthotic epidermis markedly invaginated into the underlying dermis, resulting in an open epidermoid cyst. Not only the polymerase chain reaction but also an in situ hybridization detected HPV 57 DNA in the cyst. HPV 60 is the only type of HPV that has been identified in epidermoid cysts. To our knowledge, this is the first case report of an epidermoid cyst, in which a different type of virus from HPV 60 was identified. Histological features of the cyst were also different from those of HPV 60‐associated epidermoid cysts.

Human papillomavirus-associated plantar epidermoid cyst related to epidermoid metaplasia of the eccrine duct epithelium: a combined histological, immunohistochemical, DNA–DNA in situ hybridization and three-dimensional reconstruction analysis

Background  We recently proposed that certain palmoplantar epidermoid cysts may be related to eccrine ducts and that human papillomavirus (HPV) 60 may play a role in their pathomechanism. However, the origin of palmoplantar epidermoid cysts is still controversial.

Varied clinical morphology of HPV‐1‐induced warts, depending on anatomical factors

The clinical and histological features of 49 lesions induced by human papillomavirus type 1 (HPV‐1) were studied. The majority of cases showed the typical clinical features and location of such lesions. They were usually located on the ventral or lateral surfaces of the hands or feet, and were dome‐shaped lesions with a central depression.

Late onset dermal melanocytosis: an upper back variant.

Seven elderly Japanese men with blue macules on their upper backs are reported. Histological examination showed this pigmentation to be melanosis due to the presence of spindle‐shaped or oval pigment‐laden cells in the dermis. Electron microscopy revealed the cells to be compatible with dermal melanocytes. We assume that this condition belongs to the category of late onset dermal melanocytosis and is an upper back variant. This concept has not been proposed before.

Topical Vitamin D3 Derivatives in Treating Hyperkeratotic Palmoplantar Eczema: A Report of Five Patients

The treatment of hyperkeratotic palmoplantar eczema is notoriously difficult. A considerable number of patients do not or only partially respond to the current treatments such as topical corticosteroids, topical keratolytics, or PUVA therapy. The purpose of this pilot study was to look for an alternative treatment for hyperkeratotic palmoplantar eczema. We treated five patients with topical vitamin D3 derivatives (calcipotriol 50 μg/g and maxacalcitol 25 μg/g ointments). The lesions almost disappeared after 2 to 8 weeks of treatment in four patients and extremely improved with a seven week treatment in one patient. No adverse effect was observed during or after the treatment, and routine laboratory investigations were within normal ranges. When relapses occurred, they responded well to retreatment. Although the study is preliminary, the results suggest that vitamin D3 derivatives offer a safe, effective alternative form of treatment for recalcitrant hyperkeratotic palmoplantar eczema.

Extramammary Paget's disease not only mimicking but also accompanying condyloma acuminatum: A case report

Although its significance remains unknown, it has recently been reported that epidermal papillomatous hyperplasia could be frequently found in extramammary Paget’s disease (EMPD). The simultaneous occurrence of EMPD and various human-papillomavirus (HPV)-associated neoplasms has also been reported. We report a case of a perianal EMPD with multiple verrucous papules on its surface. Histologically, the verrucous papules consisted of two distinct histological patterns; one showed numerous Paget’s cells within the hyperplastic epidermis with papillomatosis, and the other showed the features compatible with condyloma acuminatum (CA). HPV-6 DNA was demonstrated in koilocytic keratinocytes of the CA by in situ hybridization. No positive signal was obtained for targeted HPV type 6/11/16/18/31/33 DNA in either the verrucous or plaque EMPD. Since the verrucous papules were localized on the plaque of EMPD, our case suggests that some undetermined EMPD-related factors may contribute to the development of epithelial hyperplasia, including HPV-associated neoplasms.