Benign lymphoepithelial tumor of the skin ("cutaneous lymphadenoma")

"Benign lymphoepithelial tumor of the skin" or "cutaneous lymphadenoma" is a distinctive benign adnexal tumor presenting a characteristic combination of lobules of epithelial basaloid cells with a peculiar histopathological pattern and a dense intraepithelial T-cell lymphoid and histiocytic population. We report an additional example of this peculiar neoplasm. In addition to the characteristic histopathological features, focal areas showing unequivocal follicular differentiation were observed at the periphery of the tumor. In agreement with other authors we consider that this neoplasm should be included within the spectrum of neoplasms of pilosebaceous origin. Nevertheless, we consider that the original and simple concept of "benign lymphoepithelial tumor of the skin" seems more suitable and illustrative than the more widely used term of "cutaneous lymphadenoma" to define this rare benign adnexal neoplasm.     

Cutaneous lymphadenoma

Cutaneous lymphadenoma is a rare tumor with distinctive histologic features. This entity was originally described as lymphoepithelial tumor by Santa Cruz and Barr in 1987. It was renamed cutaneous lymphadenoma in 1991. To date, at least 31 cases of this entity have been reported. The literature did not contain a clinical photograph of this lesion. A case of this rare tumor is described that includes clinical and histologic features. The literature regarding the unclear histogenesis of this distinctive tumor is reviewed. This report is one of a only few clinical illustrations of cutaneous lymphadenoma. Consistent with previous reports, the histologic findings in this case include basaloid proliferation and intraepithelial lymphocytes. The usual initial clinical diagnosis is basal cell carcinoma localized mainly to the head and neck area. The incidence is approximately equal in male and female patients. Excision of this benign neoplasm is curative. Controversy exists regarding the histogenesis of this tumor.     

Cutaneous lymphadenoma is distinct from basal cell carcinoma

Background Cutaneous lymphadenoma is a recently recognized unusual tumor. It presents as an indistinct solitary non-ulcerating dermal nodule occuring mostly in the head and neck region of middle aged persons. Its histogenetic definition is controversial and recently it has been proposed that it might represent an unusual inflammatory basal cell carcinoma. We present clinical, hislological and immunohistochemistry data of two cases. For the first time lectin-imrnunohistochemisiry of cutaneous lymphadenoma is reported on. Observations One tumor was located on the eyebrow of a 37 years old, the other on the nose of a 75 years old male patient. Slow growth over years occured. Histology showed biphasic pattern of elongated and angulated lobules with peripheral rim of basaloid cells and central network of lymphohisltocytic cells with preponderance of protein S 100-positive cells. Peanut agglutinin (PNA) did not show peripheral staining around tumor lobules as seen in basal cell carcinoma. Conclusions Clinical and histological features as well as absence of peanut agglutinin staining argue in favor of the distinction of cutaneous lymphadenoma from inflammatory basal cell carcinoma. The former probably represents a benign growth of adnexal origin.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大。组织病理：真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润。免疫组化：淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100＋和CD1a＋树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达。根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞。     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

皮肤淋巴腺瘤二例组织学及免疫组化研究

2例均为发生于面部的单发结节,光滑,粉红色,缓慢增大.组织病理:真皮中不规则的上皮细胞小叶,边缘由基底样细胞呈栅栏状排列,团块中心由透明细胞构成,小叶中及间质中可见大量的小淋巴细胞浸润.免疫组化:淋巴细胞以CD3阳性为主,少量的CD20阳性细胞,上皮团块及周围间质中较多的S-100+CD1a+树突细胞,细胞角蛋白7、细胞角蛋白20、癌胚抗原均为阴性,1例团块中央少量细胞上皮膜抗原和CD30表达.根据组织病理和免疫组化结果,明确为皮肤淋巴腺瘤,其主要的浸润细胞是CD3阳性淋巴细胞.     

Immunohistochemical comparison of cutaneous lymphadenoma, trichoblastoma, and basal cell carcinoma: support for classification of lymphadenoma as a variant of trichoblastoma

Cutaneous lymphadenoma is an uncommon basaloid epithelial tumor of uncertain histogenesis, most recently classified as a variant of trichoblastoma. Because characteristic immunohistochemical findings have been reported in trichoblastomas, we evaluated the staining patterns of five cutaneous lymphadenomas and compared the results to those of ten trichoblastomas and ten nodular basal cell carcinomas (BCCs), using antibodies to cytokeratin 20 (CK20), bcl-2, and CD34. In addition, because lymphadenomas contain intraepithelial S100-positive putative Langerhans cells, we compared staining of all tumor groups for S100 protein and CD1a. We also attempted to corroborate recent reports of CD30-positive activated lymphocytes in lymphadenomas. We identified CK20-positive Merkel cells in 3/5 lymphadenomas, 7/10 trichoblastomas, and none of the BCCs. Staining for bcl-2 accentuated the peripheral epithelial layer in all lymphadenomas and in 3/10 trichoblastomas, while the remaining trichoblastomas and all BCCs stained diffusely. There was stromal staining with CD34 in two lymphadenoma, 4 trichoblastomas, and 3 BCCs. All lymphadenomas featured numerous intraepithelial S100-positive cells which were also positive for CD1a in three cases tested. In addition, 8/10 trichoblastomas and 2/10 BCCs contained modest numbers of cells labelling for S100 and CD1a. Two of three lymphadenomas contained rare single cells resembling histiocytes faintly positive for CD30, and similar cells labelled for CD68. We conclude that the similar staining patterns of lymphadenomas and trichoblastomas support the classification of lymphadenoma as a variant of trichoblastoma. Staining with CD34 does not reliably distinguish between these tumors and BCCs. Lymphadenomas, trichoblastomas, and BCCs may all contain Langerhans' cells. The relationship between these cells and the striking lymphoid infiltrates seen in lymphadenomas is not clear. In our cases, the CD30-positive cells in lymphadenomas appear to represent histiocytes rather than activated lymphocytes.     

Cutaneous lymphadenoma with ductal differentiation

Cutaneous lymphadenoma (CL) is a recently described neoplasm of unknown histogenesis. Histologically, these tumors typically present as well-circumscribed nodules with scant or no epidermal connections. They are composed of multiple rounded lobules of basaloid cells with some degree of peripheral palisading. These epithelial lobules characteristically show a dense lymphoid infiltrate within them. In cases of CL previously described, there was no obvious adnexal differentiation except for isolated cells showing apparent sebaceous differentiation or hints of follicular differentiation. We report two typical cases of CL that were studied histologically and immunohistochemically. In some of the tumor lobules, there were foci of ductal differentiation, with luminal positivity for CEA and EMA. We postulate that some CL represent a form of immature sweat gland tumor with ductal differentiation.     

Congenital cutaneous lymphadenoma

Cutaneous lymphadenoma is an uncommon benign neoplasm often considered to be an adamantinoid variant of trichoblastoma. Lesions present in both sexes, between 14 and 87 years of age, and are mainly located on the head and neck. Cases in children are rare and there is only 1 previous case of a congenital lymphadenoma. An 8‐year‐old Asian girl presented with a congenital lesion on her forehead comprising 4 pink papules, the largest 5 mm in diameter. Microscopy revealed a well‐circumscribed tumor within the dermis and subcutis comprising well‐demarcated epithelial lobules of basaloid and clear cells with subtle peripheral palisading, growing in a collagenous stroma but lacking retraction artefact. A relatively dense accompanying predominantly lymphocytic inflammatory cell infiltrate including both T‐cells (CD3+) and B‐cells (CD20+) permeated the nodules and spilled into the stroma. CD68+ histiocytes and CD1a+ Langerhans cells were moderately numerous. This is the second case of congenital lymphadenoma which—in spite of its rarity in childhood—widens the diagnostic possibilities of cutaneous lymphoepithelial tumors in children.     

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.     

Basaloid folliculolymphoid hyperplasia with alopecia as an expression of mycosis fungoides (CTCL)

Follicular mucinosis, papules, cysts and comedones have been previously described as expressions of follicular involvement by mycosis fungoides. We report a patient with mycosis fungoides who developed extensive alopecia. Multiple scalp biopsies showed perifollicular and intrafollicular infiltrate of lymphocytes but no evident follicular mucinosis. On transverse sections many of the follicles showed an absence of differentiation towards hair sheath, canal, sebaceous gland or hair formation, but instead formed undifferentiated basaloid structures. These basaloid structures showed transition from atrophic telogen follicles to hypertrophic basaloid islands infiltrated by lymphocytes, resembling the pattern previously described in cutaneous lymphadenoma. Immunophenotyping showed a predominance of helper T-cells which, on ultrastructural examination, showed cerebriform nuclei. The unusual histological findings in our case may be analogous to the hyperplasia seen in sweat glands in syringotropic mycosis fungoides (syringolymphoid hyperplasia), and we propose the term basaloid folliculolymphoid hyperplasia to describe this feature. Basaloid follicular hyperplasia has been previously described as a component of follicular mucinosis but may apparently develop in the absence of overt mucinosis.     

Trichoblastoma with Rippled-Pattern

The following is a case study of a 36-year-old Japanese man with a trichoblastoma which exhibited a rippled-pattern on the left temporal region of the scalp. The histological findings of the tumor revealed lobular aggregations composed of immature follicular basaloid cells, lobules of squamous eddy-like foci of incomplete keratinization or small keratinous cysts, and multiple papillary mesenchymal bodies similar to hair germ. Interestingly, a rippled-pattern of basaloid cells and hyalinized matrixes resembling the Verocay bodies of neurilemmoma was also observed. We propose that the rippled-pattern of the basaloid cells and hyalinized matrices is caused by the characteristic stromal induction of trichoblastoma.