CD163 is not a sensitive marker for identification of atypical fibroxanthoma

The histopathological features of atypical fibroxanthoma (AFX) overlap with those of poorly differentiated carcinoma, melanoma and leiomyosarcoma in the skin. As there are no specific stains to identify AFX, the diagnosis is essentially one of exclusion and requires completion of a panel of immunostains. Recently, it has been suggested that the macrophage/monocyte-specific marker CD163 is of value in identifying AFX. To investigate this claim, 57 AFX were stained for CD163. Only 21 of 57 (37%) of AFX stained positively, and intratumoral macrophages confounded interpretation of the stain at times. In four cases, it was not possible to definitively interpret the tumor staining reaction because of this effect. While a lack of stainable CD163 antigenicity may indicate that AFX is not of histiocytic lineage, it is conceivable that expression of the antigen has been lost for some reason in cells that are in fact of macrophage lineage. In summary, CD163 only stains a minority of AFX and staining results can be difficult to interpret. CD163 is therefore of very limited value in the diagnosis of AFX. Beer TW. CD163 is not a sensitive marker for identification of atypical fibroxanthoma.     

Antibody to S100a6 protein is a sensitive immunohistochemical marker for neurothekeoma

BACKGROUND: Neurothekeoma is a benign tumor of putative peripheral nerve sheath origin. It occurs in a myxoid (classic) variant, cellular variant, and intermediate (mixed) variant. Cellular neurothekeoma (CNT) usually involves the head and neck or extremities of young patients. Histologically, CNT can be confused with melanocytic and fibrohistiocytic lesions. An immunohistochemical antibody panel is often necessary to confirm the histological impression and exclude melanocytic and/or fibrohistiocytic lesions. METHODS: Formalin-fixed, paraffin-embedded archival tissues were evaluated by immunohistochemistry using antibodies specific for S100A6 and PGP9.5 in 11 cases of neurothekeoma (seven cellular, four myxoid). A variety of other antibodies were evaluated by immunohistochemistry at the time of initial diagnosis. RESULTS: All 11 neurothekeoma cases were positive for S100A6 protein (four cases, weak/1+; seven cases, strong/2+), corresponding to 100% sensitivity. In contrast, eight of 11 neurothekeoma cases (73% sensitivity) were positive for PGP9.5. All seven CNT cases were negative for S100B, as expected. CONCLUSIONS: Anti-S100A6 is a highly sensitive antibody for neurothekeomas, including CNT, and, in our experience, is superior in sensitivity to PGP9.5. However, like other antibodies used in evaluating neurothekeomas, S100A6 lacks specificity, as has been demonstrated in previous studies. Nevertheless, S100A6 can be useful in an immunohistochemical antibody panel to evaluate lesions where the differential diagnosis includes CNT.     

p63 is a useful marker for cutaneous spindle cell squamous cell carcinoma

BACKGROUND: Cutaneous spindle cell squamous cell carcinoma (SCSCC) is a rare variant of SCC. This lesion is sometimes difficult to diagnose based purely on morphologic features. p63 is a member of the p53 gene family that can be identified in epithelial malignancies. METHODS: Thirteen cases of spindle SCC were stained with p63, CK34betaE12, MNF116, vimentin, and S100. Control cases included desmoplastic melanoma (eight cases), atypical fibroxanthoma (AFX) (10 cases), dermatofibrosarcoma protuberans (eight cases), and cutaneous leiomyosarcoma (LMS) (four cases). RESULTS: p63 was expressed diffusely in the nuclei of 100% (13/13) of SCSCCs. Of controls, p63 showed focal labeling of two LMS and two AFX. MNF116 and CK34betaE12 were positive in 13/13 SCSCCs. Of controls, one LMS was focally positive for MNF116. All SCSCCs and all control cases were positive for vimentin. CONCLUSIONS: In the given differential diagnosis, p63 appears relatively specific to SCSCC and adds a useful nuclear marker to the available repertoire. The findings also suggest that cytokeratins MNF116 and CK34betaE12 may be more useful than standard cytokeratins in labeling SCSCC.     

CD44v6 is a marker for systemic spread in cutaneous T-cell lymphomas

Adhesion molecules are involved in leukocyte recruitment, lymphocyte recirculation, and in several aspects of tumour biology. Recent discoveries of surface proteins on tumour cells involved in tumour metastasis may explain the invasive behaviour, the migration involving reversible adhesive contacts, the release into the circulation and the extravasation of tumour cells.
CD44 is a family of glycoproteins involved in cell-cell and cell-matrix interactions. The v6 (variant exon v6) form of CD44 confers a metastatic potential onto some carcinoma cells. In the present study, the expression of CD44v6 on skin biopsies of 10 inflammatory skin diseases, 30 cutaneous lymphomas (CL), 11 reactive lymph nodes, 10 primary nodal non-Hodgkin's lymphomas (NHL) and 5 secondary nodal NHL was investigated immunohistochemically.
None of the 10 nodal NHL were CD44v6 positive for the neo-plastic B- or T-cells, whereas 11/12 CL with systemic spread showed a distinct CD44vG expression in the skin. CD44v6 was not expressed on the tumour cells of skin biopsies of patients without systemic spread (18 cases of CL). In conclusion, CD44v6 expression is connected to an aggressive behaviour of CL.     

原发性皮肤浆细胞瘤一例

<正>临床资料患者,男,72岁。主因双足弓内侧缘出现皮下结节1年余,于2013年7月16日就诊。1年前患者无明显诱因左足弓内侧缘出现皮下结节,无明显自觉症状,皮损逐渐增大,于2013年6月在当地行左足弓内侧缘皮损完全切除术后行组织病理检查,提示为皮肤浆细胞瘤,未再行特殊治疗。1周后,右足弓内侧又出现类似皮损,逐渐增大。患者既往体健,无特殊病史及药物过敏史,家族中无类     

原发性皮肤浆细胞瘤1例

报告1例原发性皮肤浆细胞瘤。患者男,76岁。初发为颌部单发的无痛性结节,后发展为多发损害。组织病理检查及免疫组化染色结果提示真皮全层及皮下脂肪克隆性浆细胞增生。患者病程近10年,长期随访及多次系统检查未发现系统受累症状,诊断原发性皮肤浆细胞瘤,给予VIP（M：骒法仑,P：泼尼松）方案化疗,取得较好的效果。     

Ber-EP4 is a useful marker for follicular germinative cell differentiation of cutaneous epithelial neoplasms

Ber-EP4 is a monoclonal antibody that recognizes 34-kDa and 39-kDa non-covalently linked glycopolypeptides expressed by most human epithelial cells and carcinomas. In this study, we performed immunohistochemical staining of 31 cases of basal cell carcinoma (BCC); 20 cases of trichoblastoma (TB), including ten cases of nodular type, eight cases of cribriform type (trichoepithelioma) and two cases of columnar type (desmoplastic trichoepithelioma); 16 cases of actinic keratosis (AK); and 10 cases each of Bowen's disease, poroma and seborrheic keratosis. Six cases of BCC and AK were co-lesions of both neoplasms. In normal skin tissue, Ber-EP4 reacted positively with the secretory portion of eccrine glands and follicular germinative cells at the lower end of catagen hairs. Neoplastic cells in 97% of cases with BCC reacted positively with Ber-EP4 in at least 5% of neoplastic cells. Those in 90% with nodular type TB and 50% with trichoepithelioma also reacted positively in at least 5% of neoplastic cells. No cases of poroma, seborrheic keratosis, AK or Bowen's disease were immunohistochemically positive for Ber-EP4 in neoplastic cells. In all six cases with co-lesions of BCC and AK, neoplastic cells of BCC reacted positively with Ber-EP4 and those of AK were negative. Immunohistochemical examination using the Ber-EP4 antibody is a useful tool for diagnosing neoplasms with follicular germinative differentiation, such as TB, TE or BCC, and for differentiating those from squamous cell carcinoma in situ, poroma or seborrheic keratosis.     

A case of a primary cutaneous plasmacytoma presenting in adolescence

Primary cutaneous plasmacytoma is defined as monoclonal proliferation of plasma cells that arises primarily in the skin without evidence of systemic disease. We present an extremely rare case of a young adult diagnosed with solitary plasmacytoma. A 20-year-old woman presented with a pruritic erythematosquamous indurated plaque on the inner aspect of her right thigh. She had undergone a biopsy 5 years ago, and under the diagnosis of Nekam disease, she was treated with topical steroids followed by intralesional injections of triamcinolone acetonide. A new skin biopsy revealed infiltration of the epidermis by small T lymphocytes while plasma cell accumulations were found in the dermis. Immunostains for light and heavy chains [kappa, lambda, immunoglobulin (Ig) G, IgA, and IgM] demonstrated IgG/κ monoclonality of the plasma cells. On molecular analysis, T-cell receptor and immunoglobulin heavy chain rearrangements were polyclonal. Serum protein electrophoresis, immunofixation, and quantitative assessment of serum Igs were normal. Bone marrow biopsy, skeletal survey, and body computed tomography scan were unremarkable. A diagnosis of primary solitary cutaneous plasmacytoma was made. The lesion was removed surgically, and the patient remains in remission up to now. Primary cutaneous plasmacytoma represents only 2%-4% of extramedullary plasmacytomas. The rarity and the nonspecific presentation of cutaneous plasmacytomas does not allow a definite clinical diagnosis. Only histopathology reveals the typical pattern of a dense monomorphic dermal plasmacytic infiltrate, whereas immunohistochemistry shows monoclonality of the neoplastic cells.     

Subacute cutaneous lupus erythematosus: a cutaneous marker for a distinct lupus erythematosus subset

We have characterized the clinical and laboratory features of 27 patients who had in common a recurring, superficial, nonscarring type of cutaneous lupus erythematosus (LE) that occurred in a characteristic distribution (subacute cutaneous lupus erythematosus [SCLE]). This clinically distinct form of cutaneous LE has not previously been analyzed as a separate entity and thus, its clinical importance has not been fully appreciated. We found that these patients frequently had a mild systemic illness marked by musculoskeletal complaints and serologic abnormalities. Forty-eight percent had systemic LE by American Rheumatism Association criteria; however, none had serious CNS or renal disease. Thus, those with SCLE are a subset of patients with LE who generally have an illness intermediate in severity between discoid LE and severe systemic LE.     

Nuclear factor XIIIa staining (clone AC‐1A1 mouse monoclonal) is a sensitive and specific marker to discriminate sebaceous proliferations from other cutaneous clear cell neoplasms

Sebaceous carcinoma is a rare but serious malignancy that may be difficult to diagnose when poorly differentiated. Other epithelial tumors with clear cell change may mimic sebaceous carcinoma. Few useful or specific immunohistochemical markers for sebaceous differentiation are available. Nuclear staining with factor XIIIa (clone AC‐1A1) was recently found to be a highly sensitive marker of sebaceous differentiation. We evaluated nuclear factor XIIIa (AC‐1A1) staining in sebaceous neoplasms vs. other cutaneous clear cell tumors. We stained 27 sebaceous proliferations: sebaceous hyperplasia (7), sebaceous adenoma (8), sebaceoma (5), sebaceous carcinoma (7). We also stained 67 tumors with clear cell change: basal cell carcinoma (8), squamous cell carcinoma (8), hidradenoma (7), desmoplastic trichilemmoma (2), trichilemmoma (10), trichilemmal carcinoma (3), clear cell acanthoma (9), atypical fibroxanthoma (1), syringoma (8), trichoepithelioma (1), metastatic renal cell carcinoma (2), and nevi with balloon cell change (8). Nuclear factor XIIIa (AC‐1A1) staining was present in 100% of sebaceous proliferations; 96% displayed strong staining. Non‐sebaceous clear cell tumors were negative or only weakly positive with factor XIIIa (AC‐1A1) in 95.5%; only 4.5% showed strong staining. This suggests that strong nuclear factor XIIIa (AC‐1A1) staining is a sensitive and specific marker of sebaceous neoplasms vs. other clear cell tumors.     

Skin tags: a cutaneous marker for diabetes mellitus

Two hundred and sixteen non hospitalized patients with skin tags (ST) were studied for the presence of diabetes mellitus (DM) and obesity. Overt DM was found in 57 (26.3%) patients and impaired glucose tolerance test was found in 17 (7.9%) patients. Sixteen new cases of DM were found among this group. All the diabetic patients in the study population had non-insulin dependent DM. Sixty-two (28.7%) of the patients were obese. No correlation was found between the localization, size, colour and number of the ST and the presence of DM. Our study indicates that ST are not associated with increased incidence of obesity compared to the general population. On the other hand, ST are associated with impaired carbohydrate metabolism, and may serve as means for identifying patients at increasing risk of having DM.     

继发性皮肤浆细胞瘤

报告1例继发于多发性骨髓瘤（multiple myelonm,MM)的皮肤桨细胞瘤，患者女，44岁，皮损为多发性，来源于MM直接蔓延和血行转移，组织病理检查示瘤细胞呈结节状浸润，免疫组化染色结果示IgG阳性表达，患者于皮损出现后78d死亡。     

Multiple familial pilomatricomas: a cutaneous marker for myotonic dystrophy

4 members of the same family with association of multiple pilomatricomas and myotonic dystrophy are described. A muscular electron microscopic study and the electromyographic findings are reported.     

Soluble E-cadherin: a novel cutaneous disease marker

E-cadherin is a major homophilic cell-cell adhesion molecule of the skin. There are two forms of E-cadherin—membrane and soluble types. Although various abnormalities of the former type have been identified in some cutaneous diseases, information relating to the latter is sparse. We measured the concentrations of soluble E-cadherin in several cutaneous diseases, and found higher levels in sera from patients with bullous pemphigoid, pemphigus vulgaris, psoriasis vulgaris and inflammatory skin diseases, compared with controls. In psoriasis vulgaris the levels of soluble E-cadherin in sera correlated with the PASI score. In normal individuals, levels in suction blister fluid were double those in sera. These findings suggest that changes occur in circulating levels of soluble E-cadherin in skin disease, possibly reflecting increased turnover and/or proteolysis of cell-surface molecules in the epidermis.     

FOXE1 is a target for aberrant methylation in cutaneous squamous cell carcinoma

Background Several cancer‐related genes are silenced by promoter hypermethylation in skin cancers. However, to date the somatic epigenetic events that occur in cutaneous squamous cell carcinoma (SCC) tumorigenesis have not been well defined. Objectives To examine epigenetic abnormalities of FOXE1, a gene located on chromosome 9q22, a region frequently lost in SCC. Methods We investigated the methylation status of FOXE1 in 60 cases of cutaneous SCC by methylation‐specific polymerase chain reaction, and comparatively examined mRNA and protein expression by real‐time polymerase chain reaction and Western blot, respectively. Results We found a higher frequency of FOXE1 promoter hypermethylation in SCCs (55%), as compared with the adjacent uninvolved skin (12%) and blood control samples (9·5%). FOXE1 methylation was frequently seen in association with a complete absence of or downregulated gene expression. Treatment with the demethylating agent 5‐Aza‐2′‐deoxycytidine resulted in profound reactivation of FOXE1 expression. Conclusions These results indicate that FOXE1 is a crucial player in development of cutaneous SCC.     

Acrokeratosis paraneoplastica—a new cutaneous marker of malignancy

The historical background and the main clinical features of a specific paraneoplastic dermatosis, acrokeratosis paraneoplastica, are reviewed. Typical features are erythematous scaly lesions on the extremities, ears and bridge of the nose, associated with a malignancy, most frequently in the laryngo-pharyngeal region.