Intra-epidermal eccrine poroma: a histochemical and enzyme-histochemical study

Eccrine poromatosis: case report and review of the literature

Eccrine poroma (EP) is a benign tumor of the eccrine duct. Multiple EPs are defined as eccrine poromatosis (EPS), an uncommon phenomenon. To date there are only eight reported cases of EPS. This review exemplifies the epidemiology, pathogenesis, differential diagnosis, and histology of EP, while reviewing the eight cases of EPS. Six of the eight cases of EPS had a history of immunosuppression from either radiation or chemotherapy. This paper will also emphasize the importance of excision to avoid possible malignancy. Here we present a 73-year-old gentleman with EPS who was also treated with radiation and chemotherapy prior to the onset of the lesions.

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.

Porocarcinoma Arising in Pigmented Hidroacanthoma Simplex

Hidroacanthoma simplex (HAS) is a rare benign tumor that is also known as intraepidermal poroma. While there have been a few reports of HAS with malignant transformation (porocarcinoma), we report an unusual case of porocarcinoma, arising in a pigmented HAS, the latter also showing secondary amyloid deposits. An 80-year-old Japanese man presented with a cutaneous tumor on his left buttock, which had first been noticed in his childhood. The tumor consisted of flat pigmented plaque and a depigmented papule with erosion. Histologic analysis revealed many pigmented and well-defined nests within the epidermis of the flat pigmented portion. The nests were composed of cuboidal to oval and occasionally elongated, bland, basaloid cells with numerous melanin granules. In addition, there were infrequently ductal structures and small clusters of sebocytes, and abundant amyloid deposits in the upper dermis. These findings were consistent with pigmented HAS with amyloid deposition. In the depigmented portion, markedly atypical cells with occasional ductal structures and intracytoplasmic lumina extended throughout the entire thickness of the epidermis, with minimal invasion of the dermis. We considered this portion of the tumor to be a porocarcinoma. Since the two portions of the tumor were continuous, we made a final diagnosis of porocarcinoma arising in pre-existing pigmented HAS with amyloid deposition.

A case of porocarcinoma from pre-existing hidroacanthoma simplex: need of early excision for hidroacanthoma simplex?

BACKGROUND

Hidroacanthoma simplex (HAS) is an uncommon eccrine neoplasm of the skin. It is a benign neoplasm, but some cases of malignant change were reported in the literature.

OBJECTIVE

To describe a rare case of porocarcinoma in a relatively short period from pre-existing HAS on the abdomen.

METHODS

Wide local excision was performed on this neoplasm.

RESULTS

There was no recurrence for 72 months after wide excision. CONCLUSION. : We recommend an early excision and careful attention in the case of HAS because of its potential malignant change.

Clear-cell porocarcinoma in situ: a cytologic variant of porocarcinoma in situ

Poromas are benign neoplasms composed of poroid and cuticular cells. Four histopathologic variants of poromas are accepted, according to the architectural features of the neoplasm: hidroacanthoma simplex or intraepidermal poroma; eccrine poroma, which is a poroma connected to the epidermis that extends to superficial dermis; dermal duct tumor, which develops when the neoplasm is composed of small, solid aggregations of poroid and cuticular cells confined to the dermis with little or no connection with the epidermis; and poroid hidradenoma, which is a solid-cystic, dermal poroma. The malignant counterpart of hidroacanthoma simplex is named malignant hidroacanthoma simplex or porocarcinoma in situ. This report describes an example of clear-cell malignant hidroacanthoma simplex, a cytologic variant of porocarcinoma in situ, which, to our knowledge, has not been previously reported. In contrast with other clear-cell neoplasms, a relation with diabetes mellitus could not be clearly established in this case.

Apocrine poroma with sebaceous differentiation

Poromas have been classified as eccrine neoplasms, but several recent reports of poroid tumors with sebaceous, follicular, and apocrine differentiation have challenged this concept. We report a case of apocrine poroma with sebaceous differentiation. A 69-year-old man presented with an asymptomatic elevated erythematous plaque. Histopathology revealed cellular nests composed of cuboidal poroid cells and sebocytes. The nests varied in size and were entirely intraepidermally arranged in a growth pattern similar to that of hidroacanthoma simplex. Given the common embryologic origin of folliculosebaceous and apocrine units, we believe that this lesion represents an apocrine poroma with sebaceous differentiation.

Malignant hidroacanthoma simplex: a case report

Hidroacanthoma simplex is a benign tumor of the skin originating from or showing differentiation to the sweat glands. It grossly resembles seborrheic keratosis of Bowen's disease and histologically shows intraepidermal focal growth of epithelial cells. Malignant transformation of this tumor is rare. We report a case of pigmented hidroacanthoma with malignant transformation in a 67-year-old woman. There was a 20-year history of a skin lesion on the right thigh, which first appeared as a small verrucous papule, progressed to a dark-brown colored patch, and then to a pigmented plaque. Histologically, the primary tumor was composed of small squamoid cells with marked cellular atypia. Most of the tumor cells were located in the epidermis. Immunohistochemically, the cytoplasm of some tumor cells showed a positive reaction for epithelial membrane antigen, but not for either carcino-embryonic antigen or the S-100 protein.

A single lesion demonstrating features of eccrine poroma and poroid hidradenoma

A case of a single poroma lesion with the features of eccrine poroma and poroid hidradenoma is reported. The patient was a 61-year-old woman with a soft nodule, light brown in color, located on the posterior aspect of the right knee and containing a pigmented papular lesion in its center. The histological features of the papular lesion and the nodule were consistent with those of eccrine poroma and poroid hidradenoma, respectively. The eccrine poroma portion consisted mostly of poroid cells. The number of cuticular cells was slightly greater than that of poroid cells in the poroid hidradenoma portion. The cuticular cells in this portion as well as the poroid cells in both portions were immunohistochemically positive for epithelial membrane antigen. The findings in this case suggest that there is a close relationship between eccrine poroma and poroid hidradenoma and support the view that poroid hidradenoma is a type of poroma.

Hidroacanthoma simplex: an ultrastructural and immunohistochemical study

A representative case of hidroacanthoma simplex was studied with routine light microscopy, immunohistochemistry, and electron microscopy. Staining with the periodic acid-Schiff reagent and immunostaining with anti-keratin antibodies were useful in demarcating the tumor cells from adjacent normal epithelium. However, antibodies to carcinoembryonic antigen and epithelial membrane antigen did not help us to segregate or identify the neoplastic cells. Electron microscopy revealed tumor cells markedly different in appearance from luminal cells of the acrosyringium. Hidroacanthoma simplex does not appear to be derived from luminal cells of the acrosyringium. We propose criteria for the histologic diagnosis of this benign neoplasm.

Comparative cytokeratin analysis of sweat gland ducts and eccrine poromas

Human eccrine sweat gland ducts and benign and malignant eccrine poromas were studied for the expression of various cytokeratins (CK) and vimentin by applying immunoperoxidase and immunofluorescence microscopy to frozen or paraffin-embedded sections, and using two-dimensional gel electrophoresis and immunoblotting. In acrosyringia and dermal eccrine ducts, the luminal cells exhibited intense staining for CKs 1/10/11 and 19. The periluminal cell layers of acrosyringia contained CKs 1/10/11, while CK 5 was absent. In contrast, the basal cell layer of dermal ducts was only positive with the antibody against CK 5, i.e. a pattern resembling that seen in epidermal basal cells. CK 9 was detected only in keratinocytes peripherally surrounding acrosyringia. In benign poromas, gel electrophoresis revealed that CKs 5 and 14 were predominant, with CKs 6, 16 and 17 being minor components. At the immunohistochemical level CKs 1/10/11 and 19 could be further detected with varying frequency in scattered or clustered cells and/or duct-like structures. Occasionally, CK 9-positive cells were observed. Malignant poromas displayed a similar overall gel-electrophoretic pattern. Their immunohistochemical staining patterns were also similar to (albeit rather more variable than) those seen in benign poromas. Our results show that, with respect to their CK expression pattern, the majority of poroma cells resemble the basal cells of both the dermal ducts and the epidermis, while only minor and variable subpopulations acquire features present in ductal/acrosyringial luminal cells that would be indicative of poral differentiation. Thus, the matrix cells of poromas seem to be most closely related to basal cells located at the transition between the glandular epidermal ridge and dermal eccrine duct, being in no way analogous to the cells of the adult acrosyringium above the basal cell level.

Malignant hidroacanthoma simplex

A case of malignant hidroacanthoma simplex is described. Histological examination revealed that the malignant cells had arisen from a tumor cell nest of benign hidroacanthoma simplex and invaded the dermis. Two years and 7 months after the excision of the original thigh lesion, a groin lymph node metastasis was discovered. The metastatic tumor cells in the lymph node were histologically similar to the carcinoma cells in the original thigh lesion and had enzymatic and ultrastructural features resembling eccrine sweat duct.

Intraepidermal pilar epithelioma: a new dermatopathologic interpretation of a skin tumor

An intraepidermally developed epithelial cell tumor, forming multiple nests, was examined to identify its cytologic characteristics. Histochemically, the tumor cells contained neither glycogen nor lipid substance. By N-(7-dimethylamino-3-methyl-4-coumarinyl)maleimide staining, the cytoplasm of the tumor cells in the periphery of each nest was rich in SH groups but not in SS linkages, whereas centrally located homogeneous tumor cells contained SS diffusely but no SH. The tumor cells showed no activity of phosphorylase and a weak activity of succinic dehydrogenase. Immunohistochemically, antihair keratin monoclonal antibodies specific for hair cells decorated the tumor cells, but carcinoembryonic antigen staining showed no positivity. Ultrastructurally, the tumor cells underwent a keratinization forming a fingerprint pattern of keratin filaments; however, membrane-coating granules and marginal bands were not formed. These intraepidermal tumor cells may have cytologic natures similar to those of hair cortical cells. The term intraepidermal pilar epithelioma is proposed as a diagnosis for this tumor.

Superficial epithelioma with sebaceous differentiation

Five cases of superficial epithelioma with sebaceous differentiation (SESD) are reported. They occurred as solitary papules on the face of 5 patients, aged 57 to 72. The tumor is characterized by a superficial platelike proliferation of basaloid to squamoid cells with broad attachments to the overlying epidermis. Clusters of mature sebaceous cells are present within the tumors. None of the tumors have recurred or spread following simple excision. SESD is a non-aggressive tumor of uncertain histogenesis with a tendency toward sebaceous differentiation.

Histopathologic concepts of intraepithelial epithelioma

Intraepithelial epithelioma (IEE) is a distinct histologic expression of a variety of epithelial processes. The most common intraepidermal tumors giving rise to this histologic pattern are seborrheic keratosis and actinic keratosis, although several others were seen in our series. We report a total of 33 cases of IEE seen during a 10-year period and a review of the literature.

The significance of atypical nuclear changes in benign eccrine acrospiromas: a clinical and pathological study of 18 cases

A clinicopathologic study of 18 eccrine acrospiromas with atypical nuclear changes is presented. The changes included nuclear pleomorphism, prominent nucleoli, chromatin condensation, multinucleate giant cells and increased mitotic activity. Of the 5 neoplasms that occurred, 2 recurred once and were histologically and clinically benign, and the other 2 recurrences were histologically malignant. One neoplasm recurred twice, the first recurrences being histologically benign and the second histologically malignant. It is suggested that such nuclear atypias in otherwise clinically and histologically benign eccrine acrospiromas may be associated with local benign recurrences some of which may undergo malignant change. Search for these nuclear changes and long follow-up of patients in whom they occur are, therefore, recommended.

Hidroacanthoma simplex--a review of 15 cases

Hidroacanthoma simplex was first described in 1956, but because of its rarity there is still confusion regarding the nomenclature of this and similar entities. The histological features of fifteen cases are presented and the literature is reviewed.

Eccrine porocarcinoma: a case report with light microscopy and ultrastructure

A case of eccrine porocarcinoma in a 63-yr-old man is reported. There was a 10 yr history of an abdominal skin lesion which recurred after cautery and metastasized to skin and abdominal lymph nodes. Histologically, the primary tumour was composed of small squamoid cells with ductal lumina. There was intraepidermal nesting spread and an invasive dermal component. Formation of intracytoplasmic lumina in cells with squamoid features, best seen on electron microscopy, pointed towards poral differentiation and was a useful diagnostic feature which persisted in the less well differentiated metastases. The role of hidroacanthoma simplex as a possible preinvasive precursor lesion is discussed. The differential diagnosis from other skin tumours is described. The literature is reviewed. Despite their sometimes innocuous histological appearance, eccrine porocarcinomas are aggressive lesions which require wide local excision of the primary site and consideration of regional lymph node dissection.

Pigmented hidroacanthoma simplex with porocarcinoma. Light and electron microscopic study of a case

A case of pigmented hidroacanthoma simplex showing malignant transformation into porocarcinoma is reported. Although no intracellular duct formation could be observed as in benign tumors, ultrastructurally the tumor cells showed characteristics similar to those of eccrine poroma. Many melanocytes were seen dispersed within the tumoral nests. The melanocyte-keratinocyte relationship was found similar to that occurring in melanoacanthoma. Porocarcinoma cells showed ultrastructural features similar to those of benign cells.

Eccrine porocarcinoma

Eccrine porocarcinoma is an extremely rare malignant skin tumor arising from the eccrine sweat duct unit (acrosyringium). It presents histologically with nests of clear tumor cells in the epidermis and superficial dermis. In addition such clear tumor cells lie isolated high up in the epidermis, closely resembling Paget cells. The various tumors, which may originate from the acrosyringium and the histologic differential diagnosis of eccrine porocarcinoma are discussed.

Dermal duct tumor

A dermal duct tumor which clinically resembled an intradermal nevus and developed on the lower back of a 59-year-old woman is described. The diagnosis could only be reached by microscopic examination. The dermal duct tumor appears to originate from cells with differentiation towards the intradermal portion of the eccrine sweat duct.

Controversies in dermatopathology

Five controversial topics in dermatopathology are discussed. Penile lesions with atypical epidermal cells in young men, neoplasms with intraepithelial cellular nests, neoplasms with a trichilemmal outer layer, neoplasms with eddies of squamous cells, and the origin of seborrheic keratoses are analyzed to suggest a means of clinical recognition and understanding.

Hidroacanthoma simplex with in situ porocarcinoma. A case suggesting malignant transformation

A case of hidroacanthoma simplex, suggesting malignant transformation into porocarcinoma in situ is reported. It represents further evidence that epidermotropic eccrine carcinoma may originate from the acrosyringium. This lesion demonstrates that the upper portion of the dermal eccrine duct may participate in the oncogenesis of hidroacanthoma simplex. It may also provide the missing link in the chain of evolution of benign eccrine poroacanthoma into porocarcinoma.

Multiple lesions of the lip exhibiting the "Jadassohn phenomenon". Review of the literature and report of a case

The clinical and microscopic features of multiple, superficial lesions of the lip and adjacent mucosa in an elderly woman are reported. The lesions had been present for many years apparently without symptoms. A histologically confusing picture gave rise to diagnostic problems. Characteristic nests of basaloid cells were present at all levels of the acanthotic epithelium together with microcysts, horn pearls and squamous cell eddies. Review of the literature revealed no previous report on similar lesions of the oral mucosa and it is suggested that the lesions closely coincide with the Jadassohn type of intra-epidermal epithelioma.