Óscar Tellechea

MONOCLONAL ANTIBODY BER-EP4 DISTINGUISHES BASAL-CELL CARCINOMA FROM SQUAMOUS-CELL CARCINOMA OF THE SKIN

Twenty-two cases of basal-cell carcinoma (BCC) and 21 cases of squamous-cell carcinoma of the skin (SCO were stained for Ber EP4 using indirect immunofluorescence and avidin-biotin-peroxidase techniques. The results showed that all BCCs were diffusely and intensely labeled, whereas none of the SCCs expressed Ber EP4. irrespective of their histological type or grade of differentiation. This difference may prove useful in (a) histologically differentiating between these two neoplasms; and (b) in clarifying the histogenesis of neoplasms considered to be intermediate between BCC and SCC, or derived from BCC. In addition, because significant differences between the staining of hair follicles and BCC were noted, evaluation for Ber EP4 expression could assist in distinguishing between BCC and hair follicles in Mohs micrographic sections.

Trichilemmal carcinoma : review of 8 cases

Clinical and hislological data from 8 trichilemmal carcinomas are reviewed. The tumors occurred mainly on sun‐exposed skin of the face of elderly people as small solitary, frequently ulcerated nodules. Histologically, they consisted of multilobulate, infiltrative growths, connected to the epidermis and piloscbaceous structures and showing features reminiscent of the outer root sheath of the hair follicle. The presence of lobules of clear, glycogen‐rich cells with peripheral palisading, hyaline basement membranes, trichilemmal keratinization, and abortive follicular sheaths and the absence of ductal or acinar differentiation allow distinction from other clear cell tumors of the skin. Although the histological picture suggests a high‐grade malignant neoplasm, trichilemmal carcinoma has an indolent course. No recurrence or metastases have been observed.

Wilms tumor 1 expression in vascular neoplasms and vascular malformations.

Background:Wilms tumor 1 (WT1) protein is expressed during angiogenesis and malignant transformation of endothelial cells and can be helpful to distinguish between proliferative and malformative vascular lesions. Methods:We evaluated retrospectively 117 vascular neoplasms and 50 vascular malformations. Vascular neoplasms included infantile hemangioma (n = 87), noninvoluting congenital hemangioma (n = 5), rapidly involuting congenital hemangioma (n = 3), tufted angioma (n = 8), pyogenic granuloma (n = 13), and spindle cell hemangioma (n = 1). Vascular malformations were lymphatic malformations (n = 28), venous malformations (n = 16), capillary malformation (n = 1), and stage II arteriovenous malformations (n = 5). Immunohistochemical stains for WT1 and GLUT1 were performed in all lesions. Results:All 117 vascular neoplasms showed positive expression of WT1, whereas all vascular malformations in our study were completely negative for WT1 except in arteriovenous malformations, where WT1 expression was positive. Conclusions:The comparison between vascular neoplasms and vascular malformations showed that GLUT1 expression is positive only in infantile hemangiomas, whereas WT1 positivity is found in all vascular neoplasms and in arteriovenous malformations. WT1 antibody is an ancillary test that can be helpful to differentiate vascular neoplasms from most vascular malformations.

Dermal cylindroma. An immunohistochemical study of thirteen cases.

Thirteen dermal cylindromas (DC) have been studied immunohistochemically using a panel of antibodies that stain different portions of normal eccrine and apocrine glands. Distinct staining patterns were found in the different cell populations of the tumor. Although the expression of cytokeratins (CK) 19 and 1/10/11 in occasional duct structures could indicate excretory (ductal) differentiation, a link between DC and apocrine secretory coil is suggested by the expression of α-1-antichymotrypsin, lysozyme, human milk factor globulin 1, α smooth muscle actin (1A4), and CK 8 and 18. The presence of intermingled S-100 protein-, HLA DR-, and CD1a-positive cells argues for the existence of Langerhans cells within the neoplasm. DC shares epithelial membrane antigen, carcinoembryonic antigen, mucin-like carcinoma-associated antigen (B12), laminin, collagen IV, fibronectin, and CD34(QBEND/10) expression with both eccrine and apocrine glands.

Pyoderma gangrenosum – a review of 24 cases observed over 10 years

Background and objectives  Pyoderma gangrenosum (PG) is a disorder, included in the spectrum of neutrophilic and auto‐inflammatory dermatoses, whose clinical aspects and outcome we intend to characterize.

Livedoid vasculopathy and hypercoagulability in a patient with primary Sjögren's syndrome

Background  A 31‐year‐old woman presented with a 5‐year history of painful ulcerations, palpable purpura, porcelain‐white atrophic scars of the malleolar region and dorsal aspect of the feet, livedo reticularis on the limbs, arthralgia, xerophthalmia, and xerostomia.

Hobnail hemangioma reclassified as superficial lymphatic malformation: A study of 52 cases

BACKGROUND Hobnail hemangioma (HH) is currently classified as a benign vascular tumor, although it is not well understood whether this lesion differentiates toward blood or lymphatic endothelial cells. Immunostaining with the endothelial marker Wilms tumor 1 (WT1) helps distinguish between vascular neoplasms and malformations, being positive in the former and negative in the latter. OBJECTIVE We sought to investigate WT1, human herpesvirus 8 latent nuclear antigen, D2-40, and Ki-67 immunoprofile in HH, to gain further insight into its histogenesis. METHODS We evaluated 52 HHs collected in Dermatohistopathologische Gemeinschaftslabor, Friedrichshafen, Germany. Immunohistochemical expression of WT1 was performed in all cases. Ten of 52 lesions were also studied for D2-40 and Ki-67 staining and 12 lesions were stained for human herpesvirus 8 latent nuclear antigen. RESULTS All 52 HHs were completely negative for WT1 immunostaining. Immunohistochemistry performed in 10 HHs showed diffuse and strong positive staining for D2-40 in 8 lesions and focal positivity in two. All cases tested showed negative staining for Ki-67 and human herpesvirus 8 latent nuclear antigen. LIMITATIONS There are no limitations. CONCLUSIONS Although the exact histogenesis of HH is unknown, most of the performed immunohistochemical studies support a lymphatic line of differentiation. However, on the basis of the WT1 negativity, we believe that HH is better considered as a lymphatic malformation rather than a lymphatic neoplasm.

Tubular apocrine adenoma with eccrine and apocrine immunophenotypes or papillary tubular adenoma

A case of papillary tubular adenoma is reported. On microscopic examination the lesion, located on the scalp, showed a tubular-branching pattern, opening on the skin surface, and features of decapitation secretion. Immuno histochemical evidence of both eccrine and apocrine differentiation was found. This case, which on a clinico-pathological basis alone could be classified as tubular apocrine adenoma, illustrates the difficulties in contrasting the latter to its eccrine counterpart (papillary eccrine adenoma) and suggests that the terms papillary tubular adenoma or tubulopapillary hidradenoma more accurately describe these lesions.

Epidemiology of basal cell carcinomas and squamous cell carcinomas in a Department of Dermatology: a 5 year review

BACKGROUND Non-melanoma skin cancer, a common designation for both basal cell carcinomas and squamous cell carcinomas, is the most frequent malignant skin neoplasm. OBJECTIVE Epidemiologic characterization of the population with Non-melanoma skin cancer. METHODS Retrospective analysis of all patients diagnosed with Non-melanoma skin cancer based on histopathologic analysis of all incisional or excisional skin biopsies performed between 2004 and 2008 in a Department of Dermatology. RESULTS A total of 3075 Non-melanoma skin cancers were identified, representing 88% of all malignant skin neoplasms (n=3493) diagnosed in the same period. Of those, 68,3% were basal cell carcinomas. Most Non-melanoma skin cancer patients were female and over 60 years old. Of all Non-melanoma skin cancer, 81,7% (n=1443) were located in sun-exposed skin, and represented 95,1% of malignant skin neoplasms in sun-exposed skin. Non-melanoma skin cancer was the most frequent malignant skin neoplasm in most topographic locations, except for abdomen and pelvis - over 95% of all malignant skin neoplasms in the face, neck and scalp were Non-melanoma skin cancer. Basal cell carcinomas were clearly predominant in all locations, except in upper and lower limbs, lower lip and genitals, where squamous cell carcinomas represented respectively 77,7%, 77,4%, 94,7% and 95,3% of the Non-melanoma skin cancers. CONCLUSION Being the most common skin cancer, Non-melanoma skin cancer should be under constant surveillance, in order to monitor its epidemiologic dynamics, the efficiency of preventive measures and the adaptation of the healthcare resources.

Cutaneous sarcoidosis: a histopathological study

Background  Sarcoidosis is a granulomatous disease of uncertain aetiology in which the skin is frequently involved. Naked sarcoidal granulomas are the characteristic histological feature in specific lesions of sarcoidosis.