Dilated pore: a case report and an immunohistochemical study of cytokeratin expression

We report a 71-year-old Japanese female with a dilated pore in the form of a nodule above her right eyebrow. Histologic examination revealed a flask-shaped, keratinous cystic structure that was continuous with the surface epidermis and had numerous elongated rete ridges in the lower portion. An immunohistochemical study using a panel of monoclonal antibodies against cytokeratins (CKs) and involucrin detected CK1 and CK10 in the suprabasal cells of the cystic structure. CK8 and CK19 expression was observed in the outermost layer of some elongated rete ridges; it was composed of pallisading columnar cells. Most parts of the outermost layer of the cystic structure stained positively with AE1 antibody. From these immunohistochemical findings, we speculated that the dilated pore in our case was an isolated clinical entity is a follicular tumor differentiating mainly toward the infundibulum and partly toward the isthmus.     

Dilated pore of Winer

Two cases of dilated pore of Winer were observed. First case had single defined black papule with well defined margin, central pore and discharge of black powdery material from nose since 3 years. The second case had one 9 mm, black well-defined papule with central pore discharging black powdery material on right forearm since 9 months and 9 similar smaller papules were seen on forearm and lower abdomen. Histopathologically both revealed greatly dilated infundibulum lined by acanthotic epidermis and atrophic subinfundibular hair structures thus confirming diagnosis of dilated pore of Winer.     

Follicular germinative cells in pilomatricoma

Pilomatricoma is a follicular neoplasm that shows differentiation towards the follicular matrix, as characterized by matrical cells and shadow cells. In addition, this is sometimes accompanied by differentiation toward the follicular infundibulum and outer root sheath. These finding suggest that pilomatricoma can subtly differentiate towards any structure of the follicle. However, morphologically, no distinct germinative cells resembling embryonic follicular germ cells have been found in pilomatricoma to date. We report on two cases of pilomatricoma in which distinctive follicular germinative cells palisaded at the edges of collections of matrical cells. We propose two explanations: one is that the metrical cells of pilomatricoma can focally de-differentiate to form follicular germinative cells, and the other is that these follicular germinative cells are the precursor cells of pilomatricoma.     

Tumor of follicular infundibulum with unique features

Tumor of the follicular infundibulum is a rare benign cutaneous adnexal neoplasm with variable clinical presentation. In most cases the diagnosis is made with the help of histopathology, due to lack of a characteristic clinical presentation. The most common form is a solitary lesion, but it can be multiple or eruptive, then called infundibulomatose. This case report illustrates a patient with multiple lesions of tumor of the follicular infundibulum with bizarre aspect and atypical location.     

Immunohistochemical study of calretinin in normal skin and cutaneous adnexal proliferations

Calretinin is a calcium-binding protein member of the EF-hand family. The presence of calretinin has been demonstrated in certain stages of the cellular cycle in a wide variety of normal and neoplastic tissues. The main aims of our study were (1) to investigate what structures of the normal skin and cutaneous adnexal proliferations express immunoreactivity for calretinin and (2) to determine the value of immunohistochemical expression for calretinin as a marker for follicular, sebaceous, apocrine, and eccrine differentiation in cutaneous adnexal proliferations. We studied 139 biopsy specimens, including 10 cases of normal skin of different locations and 129 benign and malignant cutaneous adnexal proliferations. In normal skin, we found that calretinin is expressed in the innermost cell layer of the outer root sheath in anagen hair follicle, in both the duct and sebolemma of the sebaceous gland, in the secretory portion of eccrine glands, and in mast cells of the stroma. In cutaneous adnexal proliferations, we found strong immunoreactivity for calretinin in tricholemmal cysts, tricholemmomas/inverted follicular keratoses, tumors of follicular infundibulum, and in some basal cell carcinomas. Focal positivity was also seen in trichoadenomas, trichoblastomas/trichoepitheliomas, pilomatricomas, proliferating tricholemmal tumors, pilar sheath acanthomas, trichofolliculomas, follicular hybrid cysts, cutaneous mixed tumors, steatocystomas, sebaceous hyperplasias, and sebaceomas. These results demonstrate that immunohistochemical study for calretinin may be helpful to identify the innermost cell layer of the outer root sheath in anagen hair follicle and the cutaneous adnexal proliferations showing differentiation toward this structure. Calretinin immunoreactivity supports eccrine differentiation in some sweat gland neoplasms, and it is also useful in identifying neoplasms with ductal sebaceous differentiation.     

Metastasizing adenocarcinoma and multiple neoplastic proliferations arising in a nevus sebaceus

Nevus sebaceus of Jadassohn is a hamartoma of multiple skin structures. Many neoplasms have been reported to arise in association with nevus sebaceus, most commonly trichoblastoma/basal cell carcinoma and syringocystadenoma papilliferum. We report a case of a 66-year-old woman with an adenocarcinoma as well as multiple neoplastic proliferations arising in a long standing nevus sebaceus on the scalp, with subsequent occipital neck metastatic disease. On histologic evaluation, the epidermis showed changes reminiscent of tumor of the follicular infundibulum as well as basaloid proliferations resembling superficial trichoblastoma. A focus suggestive of syringofibroadenoma was also present. A small dermal collection of basaloid and more mature sebocytes was consistent with a sebaceoma/sebaceous epithelioma. Most of the lesion was composed of an adenocarcinoma with areas showing ductal differentiation with decapitation secretion, well-formed papillae and focal cribriform structures. Other portions demonstrated a high-grade neoplasm with prominent nuclear atypia and a solid pattern of growth resembling high-grade breast carcinoma. Anti-epithelial membrane antigen strongly labeled tumor cells and highlighted ductal structures. Less than 1% of cells expressed progesterone or estrogen receptors. Her2/neu reactivity was focally present, showing 1+ membranous reactivity in 10% of cells. Anti-p63 labeled basaloid cells surrounding the tumor lobules. A breast primary was ruled out by clinical and radiologic examination. This report illustrates an extraordinary case of adnexal neoplasia displaying various lines of differentiation arising in association with nevus sebaceus.     

Autoimmune acrosyringitis with ductal cysts: reclassification of case of eruptive syringoma

Syringomas are architecturally complex tumors composed of small, cystically dilated segments of dermal eccrine duct. Syringomas typically form isolated flesh-colored periorbital papules, however, in a peculiar condition termed eruptive syringoma; scores develop simultaneously in near confluence over a large surface area. While traditionally regarded as a neoplasm, more recent observations indicate eruptive syringoma is a reactive proliferation secondary to autoimmune disruption of the acrosyringium. We present the case of a 44-year-old woman with eruptive syringoma of the labia majora and prominent lymphocytic inflammation in the acrosyringium. Immunohistochemical stains confirm that the infiltrate is composed of CD4+ and CD8+ T cells, without significant CD20 B cells or CD138 plasma cells. Sequential sections of the syringoma reveal a complex 3-dimensional architecture with functionally isolated cysts, not connected to adjacent cysts or ducts by a discernable epithelium. These findings support the conclusion that eruptive syringoma is a tortuous proliferation of dermal eccrine ducts and fibrous stroma secondary to autoimmune destruction of the acrosyringium. Conceptually, the disorganized expansion of an eccrine duct syringoma may be analogous to a peripheral nerve traumatic neuroma.     

Multiple clear cell trichoblastoma

Clear cell trichoblastoma is a very rare neoplasm with follicular differentiation described recently. Only three cases of clear cell trichoblastoma were reported in literature and all of them were presented as single lesion. Here, we report a case of clear cell trichoblastoma with multiple lesions in a child. Two biopsies from the patient showed that the neoplasm was located in the dermis, and step sections showed that they were connected with the follicular infundibulum. The neoplasm was almost made of clear cells that had clear cytoplasm and eccentrically disposed nucleus. At the periphery of the neoplasm, the clear cells showed palisade array with the nucleus at the pole opposite the thick basement membrane, and only a few basal cells were located at the periphery of the neoplasm. Periodic acid-Schiff stain was almost negative in the clear cells. Immunohistochemistry studies showed the neoplasm stained positive for AE1/AE3 but negative for CAM 5.2, cytokeratin 7, cytokeratin 20, epithelia antigen, carcinoembryonic antigen, epithelial membrane antigen, androgen receptor, S-100 and CD34. The clinical and histopathological characters suggested the diagnosis of multiple clear cell trichoblastoma. After 20 months' follow up, the lesions of the patient showed incomplete regression, which is a rare phenomenon in neoplasm with follicular differentiation.     

Immunohistochemical analysis of cytokeratin expression in various trichogenic tumors.

The immunophenotypes, especially expression of cytokeratins, in 13 cases of trichogenic tumors were examined to investigate their histogenesis. Four cases of multiple trichoepithelioma, five cases of classical solitary trichoepithelioma, one case of desmoplastic trichoepithelioma, one case of trichogenic trichoblastoma, one case of trichoblastic fibroma, and one case of giant solitary trichoepithelioma were retrieved. The immunoreactivities of the epithelial nests and the keratinous cysts in these tumors were similar to those of the outer root sheath and the infundibulum of normal hair follicles, respectively. From the comparative studies of the immunophenotypes with those of normal hair follicles, we speculated that all trichogenic tumors differentiate mainly toward the outermost layer of the outer root sheath between the lower part of the permanent portion and the upper part of the transient portion and some parts of them differentiate toward various other parts of the follicles. Although differentiation toward the other follicular structures can vary from case to case, there is no particular staining pattern specific for each kind of trichogenic tumor and no significant differences in immunoreactivity among them. Our observations support a recent notion that all neoplasms of follicular germinative cells should be grouped as a single entity.     

Review of scalp alopecia due to a clinically unapparent or minimally apparent neoplasm (SACUMAN)

Neoplastic cells, both malignant and benign, local occurring and metastatic, can cause alopecia of the scalp. However, the infiltration of neoplastic cells is sometimes not florid; a condition known as "scalp alopecia due to a clinically unapparent or minimally apparent neoplasm" (SACUMAN). Neoplastic cells can nevertheless destroy hair follicles by inducing fibroplasias via inflammatory mediators, attracting inflammatory cells and/or replacing normal cellular populations. The infiltrative nature of such an alopecia can be unapparent or only minimally apparent. The most common neoplasm in which an uncomplicated, minimally or unapparent scalp alopecia occurs and no infiltrate of cancer is suspected is metastatic breast carcinoma. Other causes include squamous and basal cell carcinomas, angiosarcoma, gastric carcinoma, placental site tromphoblastic tumor, and mycosis fungoides. Syringoma-like proliferations can underlie alopecia. It is unclear whether these proliferations are true syringomas or normal findings. In conclusion, neoplasms causing cicatricial alopecia of the scalp are very rare, so generalizations from the limited number of case reports are of uncertain importance. Moreover, it is likely that many cases of neoplasms causing cicatricial alopecia of the scalp are diagnosed as inflammatory alopecia and not neoplasms, thus depriving us of a full accounting and understanding of this entity. Dermatologists must be aware that in rare cases a bland scalp alopecia can represent a new or recurring, local or metastatic neoplasm.     

Trichoblastic neoplasm with apocrine differentiation

Trichoblastoma is a benign neoplasm with primitive hair follicle differentiation. The tumor is characterized by nests and cords of epithelial cells in an organized relation to stroma. The epithelial cells differentiate toward follicular germ and follicular sheath. More divergent differentiation in the form of sebaceous elements in trichoblastoma has infrequently been reported in the literature. We report a trichoblastic neoplasm showing typical features of trichoblastoma as well as areas of apocrine differentiation. The neoplasm, which was present for several months, was removed from the chin of a 31-year-old woman. Histologic examination showed a neoplasm composed of basaloid nests with occasional papillary mesenchymal bodies as well as ducts and glands exhibiting apocrine differentiation. Trichoblastoma with apocrine features is rarely reported in the literature.     

Molluscum contagiosum in a cystically dilated follicular infundibulum

We report on the hardly known development of molluscum contagiosum in a cystically dilated follicular infundibulum. The molluscum virus infection extends over two thirds of the distal cyst wall, which a rudimentary hair root ends in.     

Cutaneous histiocytic proliferations

The classification of histiocytic proliferations in the skin is confusing, largely due to faulty use of terms such as reticulum-cell sarcoma and reticulosis. Immunohistochemical staining procedures and ultrastructural studies have made it possible to differentiate the different cells of the mononuclear phagocyte system. The proliferations discussed here were those of the mononuclear phagocyte system that are associated with characteristic skin manifestations. They include proliferations of monocytes (acute monocytic leukemia), proliferations of tissue macrophages or histiocytes (histiocytic sarcoma and its disseminated form, malignant histiocytosis; familial histiocytoses; and multicentric reticulohistiocytosis), proliferations of Langerhans' cells (histiocytosis X), and proliferations of as yet undefined cells of the mononuclear phagocyte system (sinus histiocytosis with massive lymphadenopathy). Clinical features were presented, and special emphasis was placed on incidence, form, localization, histopathology, and marker profile of the proliferating cells in the skin lesions. The close relationship of the different entities was discussed, as was the importance of immune dysfunction.     

Congenital panfollicular nevus: report of a new entity

The various forms of non-melanocytic nevi (hamartomas) are usually encountered in pediatric patients, and nevus sebaceous of Jadassohn is the most common to have undifferentiated pilosebaceous units. We report a unique congenital follicular nevus that fails to meet the criteria of any previously described follicular neoplasm, despite the plethora of alternatives. Clinically considered a syringocystadenoma papilliferum, the excised lesion contained multiple dermal nodules that exhibited nearly all stages of follicular differentiation. The periodicity of the follicular proliferations was akin to normal terminal hair, and a prominent perifollicular sheath surrounded each. This benign lesion of abortive hair follicles was unassociated with any established genodermatous syndrome or other adnexal neoplasm.     

Low-grade adnexal carcinoma of the skin with multidirectional (glandular, trichoblastomatous, spiradenocylindromatous) differentiation

The conjoint occurrence of follicular, sebaceous, or apocrine differentiations in a cutaneous adnexal neoplasm is a known event, more often encountered in benign neoplasms, whereas reports of cutaneous malignant adnexal tumors with bilineage or trilineage differentiation are few. A new case of a cutaneous malignant adnexal neoplasm with multidirectional differentiation is reported here. A 57-year-old woman presented with a long-standing, slowly growing, asymptomatic solitary tumor the size of a large nut in the coccygeal area, which was surgically excised. Ten years after the surgery, there was no evidence of recurrence or metastasis. Microscopically, the neoplasm was located in the dermis with focal extension into the subcutis. It was asymmetric, horizontally oriented, and mostly composed of small nodules that varied in shape from round and oval aggregations to elongated strands and irregular islands; the nodules were either clustered, formed a jigsaw puzzle-like pattern or were dispersed. The nodules were composed of small basaloid cells sometimes intermixed with larger cells with ample cytoplasm forming glandular structures. Rare nodules resembled elements seen in a spiradenoma by containing scattered lymphocytes and globules of hyalinized eosinophilic basal membrane material. The stroma was paucicellular, but focally it resembled that seen in perifollicular mesenchyme. Mitotic figures, including abnormal ones, were infrequent, but mild nuclear pleomorphism, nuclear crowding, and individual cell necrosis were easily appreciable in both small basaloid cells and cells with clear cytoplasm. Perineural invasion was apparent. We classified this tumor as a well-differentiated adnexal carcinoma demonstrating combined follicular and apocrine differentiation. It differs from previously published cases of malignant adnexal tumors with multidirectional differentiation and further exemplifies the spectrum of diversity encountered in malignant proliferations with differentiation toward the folliculosebaceous-apocrine unit.     

Epidermal basaloid proliferation in cutaneous myxomas

BACKGROUND: Basaloid epidermal proliferations, which histologically resemble basal cell carcinoma, have been described overlying dermatofibromas. Several etiologies have been proposed. Cutaneous myxomas are also benign mesynchymal tumors. PURPOSE: Basaloid proliferations have been noted overlying cutaneous myxomas. We have undertaken a study to attempt to differentiate whether these are basal cell carcinomas or benign basaloid proliferations. METHODS: Thirty cases of cutaneous myxomas were included in this study. The lesions were stained with hematoxylin-eosin and alcian blue. Immunohistochemical staining for both epidermal growth factor receptor (EGF-r) and p53 protein was performed on the cutaneous myxomas with epidermal basaloid proliferation. RESULTS: Of the 30 cases of cutaneous myxomas, nine were found to have an associated overlying basaloid proliferation. The basaloid proliferations were limited to the epidermis overlying the myxoid changes within the dermis. Mitotic figures were rare. Staining for p53 protein showed scattered positive staining in the basal cells in both the basaloid proliferations and adjacent epidermis. EGF-r showed positive staining of the overlying epidermis and basaloid proliferation in five cases. CONCLUSIONS: We report basaloid proliferations overlying cutaneous myxomas and propose that these represent benign adnexal proliferations rather than superficial basal cell carcinoma and are analogous to the basaloid proliferations overlying dermatofibromas.     

Epithelioid angiosarcoma of the breast involving the skin: a highly aggressive neoplasm readily mistaken for mammary carcinoma

BACKGROUND: Angiosarcomas are malignant neoplasms of endothelial cells. Angiosarcoma of the breast is a rare neoplasm that behaves in a highly malignant fashion. It must be differentiated from benign vascular proliferations and from mammary carcinoma. METHODS: We report on a 49-year-old-woman who presented with a large mass involving the left breast. RESULTS: The lesion had an erythematoviolaceous hue and livedoid pattern at the periphery. Histopathologic study showed an epithelioid malignant neoplasm, and immunohistochemical studies demonstrated that neoplastic cells expressed immunoreactivity for endothelial cell markers. CONCLUSIONS: A diagnosis of epithelioid angiosarcoma of the breast was established. The patient was treated with radical mastectomy, but she refused any other additional therapy.     

Melanocytic matricoma with melanocytic atypia: report of a unique case and review of the literature

Melanocytic matricoma is a rare cutaneous neoplasm of presumed anagen hair follicle origin with approximately 10 reported cases in the literature. Melanocytic matricomas are clinically and histopathologically distinct cutaneous nodular proliferations of matrical and supramatrical cells admixed with dendritic melanocytes, which typically occur in the sun-exposed areas of elderly patients. We report a new case with additional histopathologic features not previously described. An 82-year-old white man presented with an exophytic papule of the ear clinically suspicious for basal cell carcinoma. Histopathologic examination demonstrated a polypoid neoplasm consisting of an admixture of matrical and shadow cells with numerous interspersed dendritic and epithelioid melanocytes arranged singly and in large expansile nests. An unusual feature in this case included prominent melanocytic proliferation with associated nuclear atypia and increased mitotic activity. Although atypical and malignant melanocytic colonization has been reported in basal cell carcinomas and squamoproliferative lesions, to our knowledge, it has not been previously described in melanocytic matricomas. The biologic significance of atypical melanocytic proliferations within melanocytic matricomas is uncertain and requires further study of additional cases and long-term follow-up.     

Hereditary multiple fibrofolliculomas with trichodiscomas and acrochordons

In a sibship of nine, six members had hereditary medullary carcinoma of the thyroid. Two of those with thyroid neoplasms and two without had numerous small papular skin lesions. These proved to be a type of pilar tumor that we named fibrofolliculoma. Further investigation of the total kindred of 70 showed no other evidence of thyroid neoplasm. Skin tumors only appeared after the age of 25 years. Fifteen of 37 members older than the age of 25 years exhibited the typical skin lesions. Obviously, the original sibship was the repository of two dominantly inherited traits. The fibrofolliculoma is characterized by abnormal hair follicles with epithelial strands extending out from the infundibulum of the hair follicle into a hyperplastic mantle of specialized firbrous tissue. Associated skin lesions in this kindred were trichodiscomas and acrochordons.     

Eruptive hidradenoma

This case report emphasizes two clinical findings that aid in the diagnosis of eruptive hidradenoma. They are the predilection of the lesions for the anterior rather than posterior surface of the trunk and the presence of milialike inclusions within the papules. Eruptive hidradenomas are appendageal tumors that differentiate toward intraepidermal eccrine ducts and the milialike papules represent dilated cystic ductal structures. This patient had concomitant involvement of the eyelids, which has been observed in some, but not all, cases of eruptive hidradenoma.