Hidroacanthoma simplex: a case report and analysis of 70 Japanese cases

ALA-PDT combined with CO2 laser in the treatment of malignant hidroacanthoma simplex: A case report

Hidroacanthoma simplex (HS) is a rare skin appendage tumor that typically appears on the trunk and lower limbs in the elderly. Although HS is a predominantly benign condition, the presence of cellular atypia and dermal infiltration on histological examination indicates malignant HS (MHS). 5-aminolaevulinic acid photodynamic therapy (ALA-PDT) uses a photosensitizer and corresponding light source to cause irreversible damage or death of target cells through a photochemical reaction. Here, we reported the successful treatment of a MHS patient with ALA-PDT using plum-blossom needle pretreatment combined with CO2 laser. After five courses of ALA-PDT, the lesions were completely resolved, and the autonomic activity and smooth surface of the left ring finger were restored. This suggests that ALA-PDT is an effective, minimally invasive and safe treatment modality for MHS.

Athena: Speciality Certificate Examination case for dermatopathology

This is a case for the Speciality Certificate Examination of a rare benign skin tumour and the associated histopathological features along with the histopathological features of differential diagnoses.

Hidroacanthoma simplex: dermoscopy and cryosurgery treatment

Hidroacanthoma simplex is a rare intraepidermal neoplasia that arises from the acrosyringial portion of the eccrine duct. Malignant transformation of hidroacanthoma simplex is reported in the literature and the treatment is performed with wide excision or Mohs micrographic surgery. We report the first case successfully treated with cryosurgery with a long-term follow up.

Topics in histopathology of sweat gland and sebaceous neoplasms

This article reviews several topics regarding sweat gland and sebaceous neoplasms. First, the clinicopathological characteristics of poroid neoplasms are summarized. It was recently reported that one-fourth of poroid neoplasms are composite tumors and one-fourth are apocrine type lesions. Recent progress in the immunohistochemical diagnosis of sweat gland neoplasms is also reviewed. CD117 can help to distinguish sweat gland or sebaceous tumors from other non-Merkel cell epithelial tumors of the skin. For immunohistochemical differential diagnosis between sweat gland carcinoma (SGC) other than primary cutanesous apocrine carcinoma and skin metastasis of breast carcinoma (SMBC), a panel of antibodies may be useful, including p63 (SGC⁺ , SMBC^- ), CK5/6 (SGC⁺ , SMBC^- ), podoplanin (SGC⁺ , SMBC^- ) and mammaglobin (SGC^- , SMBC⁺ ). Comparison of antibodies used for immunohistochemical diagnosis of sebaceous carcinoma (SC) suggests that adipophilin has the highest sensitivity and specificity. Some authors have found that immunostaining for survivin, androgen receptor and ZEB2/SIP1 has prognostic value for ocular SC, but not extraocular SC. In situ SC is rare, especially extraocular SC, but there have been several recent reports that actinic keratosis and Bowen's disease are the source of invasive SC. Finally, based on recent reports, classification of sebaceous neoplasms into three categories is proposed, which are sebaceoma (a benign neoplasm with well-defined architecture and no atypia), borderline sebaceous neoplasm (low-grade SC; an intermediate tumor with well-defined architecture and nuclear atypia) and SC (a malignant tumor with invasive growth and evident nuclear atypia).

Giant Hidroacanthoma Simplex Mimicking Bowen's Disease

Hidroacanthoma simplex is a benign tumor of the skin, macroscopically resembling seborrheic keratosis or Bowen's disease and histologically mimicking clonal-type seborrheic keratosis. We observed a plaque of 70 × 50 mm on the right flank part. From clinical appearance, we suspected Bowen's disease; however, based on immunohistochemical findings, we made a diagnosis of hidroacanthoma simplex.

Dermoscopy findings of hidroacanthoma simplex

Hidroacanthoma simplex (HAS), also known as intraepidermal eccrine poroma, is a rare eccrine adnexal tumor that tends to be misdiagnosed as other types of benign skin tumor, including clonal seborrheic keratosis. Notably, HAS is sometimes misdiagnosed and treated by cryosurgery as seborrheic keratosis, which could trigger the later development of porocarcinoma. Therefore, accurate diagnosis of HAS is indispensable for dermatologists to avoid the development of malignant tumors by an unsuitable treatment. In this report, we present the characteristic dermoscopy findings of HAS. Indeed, the dermoscopy findings might be related to the melanin-rich necrotic cells in the epidermis, which are quite different from dermoscopy findings of clonal seborrheic keratosis. As a previous report suggested, it is difficult for a dermatologist to differentiate HAS from clonal seborrheic keratosis by the naked eye. Our findings might be supportive for the early diagnosis of HAS.

Unusual sites for poromas are not very unusual: a survey of 101 cases

BACKGROUND

Poromas are benign adnexal tumours generally believed to be of eccrine origin, which usually develop on palmoplantar sites. However, it is thought that a percentage of poromas develop on non-palmoplantar or 'unusual' sites.

AIM

To review cases of poromas with reference to their clinicoepidemiological characteristics, paying particular attention to the those located on sites other than the palms and soles.

METHODS

All histologically confirmed poromas seen at our department between 1994 to 2012 were reviewed. The clinicoepidemiological data recorded included age at diagnosis, gender, location, size, colour, and preoperative and pathological diagnoses.

RESULTS

In total, 101 poromas were reviewed, corresponding to 0.0058% of all the epithelial skin tumours biopsied in our department. The mean age was 65.05 years (range 30-100 years), and the male to female ratio was 1.52. All the lesions were solitary and asymptomatic, with no sign of bleeding. The most common presentation was a red or reddish lesion, particularly at palmoplantar sites, where 33 (32.7%) of the 101 poromas were located, Poromas found at other affected sites were more usually skin-coloured, and these lesions included 7 neoplasms located in the armpits and 18 on the head and neck. The correct preoperative diagnosis was made in 12 cases of 33 detected poromas (36%), all of which were localized to the palmoplantar surfaces.

CONCLUSIONS

Based on our experience, we consider that there are no 'unusual' sites for poromas, and palmoplantar poromas were in fact in the minority. Furthermore, some localizations suggest derivation of these palmoplantar poromas from the folliculosebaceous apocrine unit.

A case of hidroacanthoma simplex

We report a case of hidroacanthoma simplex with giant lesion that was found on the left lumbar part which was treated with surgical excision.

Pigmented hidroacanthoma simplex: A diagnostic pitfall

Hidroacanthoma simplex (HAS) is a rare skin appendage tumor and is recognized as an intraepidermal variant of poroma. Pigmented HAS is an extremely rare variant with dendritic melanocytes and/or melanin pigment in the tumor cells and a few cases of pigmented HAS have been reported in the English literature. We herein report a case of pigmented HAS and discuss the clinicopathological features of pigmented HAS and the pitfall in the diagnosis of black lesions.

A case of porocarcinoma arising in pigmented hidroacanthoma simplex with multiple lymph node, liver and bone metastases

Porocarcinoma is a rare skin appendage carcinoma that may arise de novo or be associated with pre-existing poroma and hidroacanthoma simplex (HAS). Here, we report a case of porocarcinoma arising in pigmented HAS, which led to death from multiple lymph node, liver and bone metastases. A 72-year-old Japanese man presented with a brown to focal black flat plaque, measuring 17 × 12 mm, on the posterior region of his right thigh. Histopathological study of the tumor revealed that there was intraepidermal proliferation of small-sized basaloid cells, and it exhibited the 'Jadassohn phenomenon', with dendritic melanocytes, and a few ductal structures were observed. Continuing to the intraepidermal nests, the invasive proliferation of large polygonal cells with occasional intracytoplasmic ductal structures was observed. Carcinoembryonic antigen and epithelial membrane antigen were expressed in some carcinoma cells and they highlighted the intracytoplasmic ductal structures. Multiple lymph node, liver and bone metastases were observed, and the patient died 8 months after the initial surgery. Clinical diagnosis of HAS is extremely rare. Porocarcinoma may be associated with pre-existing HAS and sometimes shows aggressive behavior. Therefore, pigmented HAS must be included in the differential diagnosis of brown or black lesions. Ishida M, Hotta M, Kushima R, Okabe H. A case of porocarcinoma arising in pigmented hidroacanthoma simplex with multiple lymph node, liver and bone metastases.