Histomorphological and immunophenotypical spectrum of cutaneous myoepitheliomas: A series of 35 cases.

Myoepithelial tumors comprise a group of mesenchymal lesions that show heterogeneous histomorphological features, including dual epithelial, neural, and myoid differentiation. Cutaneous myoepithelioma is a rare neoplasm that is composed primarily of myoepithelial cells and represents one end of a histopathological spectrum of cutaneous myoepithelial neoplasms including chondroid syringoma and myoepithelial carcinoma. These tumors display a wide histopathological spectrum and immunophenotypical profile often showing epithelial and myoepithelial differentiation. In this series, we studied 35 cases of cutaneous myoepitheliomas. Our cases highlighted the broad histopathological range where most cases showed a non-infiltrative and non-encapsulated tumor exclusively located in the dermis and with no subcutaneous involvement. The majority of our cases had a solid growth pattern (syncytial pattern) and the remainder of cases had a multinodular growth pattern. The tumor cells were epithelioid in 23 cases, spindled in eight cases and there was a mixture of epithelioid and spindled cells in four cases. Mitotic figures ranged from 0 to 5 per 10 HPF. By immunohistochemistry epithelial membrane antigen (EMA) was expressed in 59% of cases S100 was positive in 88% of cases, CAM 5.2 was positive in 16% of cases, AE1/AE3 was positive in 44% of cases, p63 was positive in 17% of cases, smooth muscle actin was positive in 38% of cases, desmin was positive in 6% of cases, calponin was positive in 22% of cases, and glial fibrillary acidic protein was positive in 36% of cases. In addition, there were five cases without EMA, keratin, or p63 expression that only showed S100 expression. We describe a large series of cutaneous myoepitheliomas delineating their histomorphological spectrum and immunophenotypical profile. Awareness of some of the unusual histopathological features and the heterogeneous immunohistochemical may pose difficulties for the diagnosis.

Sebaceous Carcinomas: A Clinicopathological Comparison of Ocular and Extraocular Variants.

ABSTRACT: Sebaceous carcinomas (SC) are rare tumors and are currently classified into ocular and extraocular variants. Both variants of SC have very different clinical behavior and different histomorphologic appearance; however, published data are confounding as literature describes prognosis of both variants is similar or even that extraocular variants are more aggressive. In this study we evaluated the clinical and the histopathology of ocular and extraocular SC to confirm the difference between them. We performed a retrospective review of SC in which we studied the clinical and histomorphologic features of 106 cases, including 39 cases of ocular SC and 67 cases of extraocular SC. Only 2/67 cases of extraocular SC had multiple recurrences and none of them metastasized as opposed to our cases of ocular SC wherein 21/39 cases were locally aggressive with multiple recurrences and 5 cases metastasized. Histologically, both neoplasms showed major distinct morphologic features including poor differentiation in cases of ocular SC and well-differentiated tumors in the extraocular anatomic sites. To the best of our knowledge, this is the first case series of SC that compares the clinicopathologic features of ocular and extraocular variants. Awareness of such discrepancy is key to understand this disease and to possibly diagnose and manage these patients accordingly.

Comparison of melanoma gene expression score with histopathology, fluorescence in situ hybridization, and SNP array for the classification of melanocytic neoplasms.

While most melanomas can be distinguished from nevi by histopathology, the histology is ambiguous for some melanocytic tumors, contributing to diagnostic uncertainty. Therefore molecular assays, including FISH or SNP array, and more recently a gene expression test (myPath, Myriad Genetics) have been proposed to aid in the work-up of ambiguous tumors. Two hundred and sixty-eight prospectively submitted cases were gathered, with the goal of comparing the myPath assay to morphologic diagnosis in (1) morphologically unequivocal cases (198), and to morphologic diagnosis and FISH in (2) morphologically ambiguous cases (70). Melanoma FISH was performed using probes for 6p25, 6q23, 11q13, Cep6, 9p21, and Cep9 and scored according to established criteria. The myPath assay was scored by the manufacturer as benign, indeterminate, or malignant. In the unequivocal group, myPath assay showed 75% agreement with morphologic diagnosis, with 67% sensitivity and 81% specificity. In the ambiguous group, FISH and myPath showed 69% inter-test agreement. For these cases agreement with histopathologic interpretation was 84% for FISH and 74% for myPath. Sensitivity and specificity of FISH was 61 and 100%, 50 and 93% for myPath, respectively. Cases from both groups in which myPath was discordant with either morphologic diagnosis and/or FISH (81/268 cases), were submitted for evaluation by two experienced dermatopathologist and also by SNP-array. SNP-array results correlated better than FISH, which correlated better than myPath, with the morphologic interpretation. Our findings document that molecular diagnostics show good correlation with consensus diagnoses, but discordant results occur, and vary in level of correlation with consensus interpretations. Studies with long-term outcomes data within specific ambiguous lesion subsets are required to establish the accuracy of this test, as each molecular diagnostic technique has limitations based on both lack of clinical outcomes data in ambiguous melanocytic tumors and in terms of their sensitivity and specificity in melanocytic lesion subtypes.

Factitious Dermatitis Due to Thermal Burn With Histologic Features Simulating Fixed Drug Eruption.

Factitious dermatitis (FD) (dermatitis artefacta) is rare and often difficult to diagnose because of conflicting history and nonspecific clinical and histologic findings. It can present with varied clinical features including geometric ulcers, erosions, and less commonly bullae secondary to external trauma from chemicals, electric burns, heat, and suction. Herein, we describe a case of bullous FD due to thermal burn with histologic features demonstrating overlap with fixed drug eruption. Histopathology demonstrated a subepidermal blister with epidermal necrosis along with pigment incontinence and dermal eosinophils and neutrophils. Although these features, and the clinician's impression, were suggestive of fixed drug eruption, several morphologic findings allowed accurate diagnosis of FD: sharp demarcation of necrotic keratinocytes from adjacent uninvolved epidermis, elongated keratinocytes reminiscent of thermal or electrical artifact, and multinucleated keratinocytes. Although FD is often considered a diagnosis of exclusion, these clues may help dermatopathologists distinguish this entity from inflammatory dermatoses.

Intraprostatic spermatozoa: zonal distribution and association with atrophy.

Intraprostatic spermatozoa (IS) have been demonstrated in only 2 articles in the literature reporting on postmortem prostates. Intraprostatic spermatozoa have not been previously described in radical prostatectomies. This is the first study that describes the presence of IS in radical prostatectomies with prostatic carcinoma (PC) and its association with atrophy. We examined whole mount sagittal sections from 69 consecutive radical prostatectomy cases for PC. A central section including the seminal vesicle ejaculatory duct urethra complex (SVEDU) from each case was stained with Berg's stain to identify spermatozoa and their location. The extent and the type of atrophy were assessed on the entire prostate by using a grid method. Eighteen cases (26.1%) revealed spermatozoa both in the SVEDU and in the prostate (IS) (group 1). Twenty-two cases (31.9%) showed spermatozoa exclusively in the SVEDU but not in the prostate (group 2). The remaining 29 cases (42.0%) had no spermatozoa in either site. Location of IS was 72.2% peripheral zone, 22.2% central zone, and 5.6% transitional zone. Intraprostatic spermatozoa were frequently seen accompanied by inflammatory infiltrate in the periglandular stroma. The extent of atrophy was greater in group 1 than in group 2 (25.7% versus 15.3%; P = .006). Postatrophic hyperplasia was seen more frequently in group 1 than in group 2 (72.2% versus 40.9%; P = .025). In conclusion, the frequency of IS is 26.1% when including all prostates and 45.0% when including prostates with evidence of residual ejaculate (spermatozoa in the SVEDU), more than previously reported. Intraprostatic spermatozoa are predominantly located in the peripheral zone similar to atrophy and PC. Prostates with IS have larger atrophic areas and increased frequency of postatrophic hyperplasia. The role of IS in the pathogenesis of prostate inflammation and atrophy should be investigated.

Tactile-like corpuscles in gastric mucosa: a case report.

BACKGROUND: The presence of tactile corpuscle-like structures in Schwannomas, Neurofibromas and Neuroid Intradermal Melanocytic Nevi is well-documented. We report a case describing the presence of such structures in the lamina propria of grossly normal gastric mucosa. CASE PRESENTATION: A 30 year-old male underwent esophagogastrectomy for carcinoma. Examination of hematoxylin and eosin stained sections reveal tactile corpuscle-like structures in the mucosa adjacent to the main tumor mass. CONCLUSION: This is a rare phenomenon and a literature search revealed only one paper describing such structures in the benign colonic mucosa of a colectomy done for carcinoma. We did not come across any cases in the literature describing such structures in gastrointestinal specimen resected for reasons other than carcinoma. To our knowledge this would be the first case reporting the existence of tactile corpuscles-like structures in gastric mucosa.

Lipofuscin pigment can be used as a prognostic marker in prostatic adenocarcinoma.

Lipofuscin, known as the "wear and tear" pigment, is seen in cells undergoing regressive changes, the seminal vesicles and the ejaculatory ducts. It is also present in prostatic adenocarcinoma. The purpose of this study is to evaluate the prognostic significance of lipofuscin in prostatic adenocarcinoma. Lipofuscin was evaluated in 736 hematoxylin-eosin-stained slides from 60 conventional and whole-mounted consecutive radical prostatectomies from December 1996 to February 2002. The adenocarcinoma cases were divided into lipofuscin-positive group and lipofuscin-negative group. The Gleason score and pathologic stage were compared between the 2 groups. Percentage of cells positive for p53 and MIB-1 was also compared. Lipofuscin pigment was found in 17 (31%) of 60 prostatic adenocarcinomas as random, sparse, fine, yellow-brown intracytoplasmic granules staining positive for cathepsin D and negative for S-100 protein. Using logistic regression to exclude age as a confounding factor, lower Gleason scores and pathologic stages were demonstrated in the lipofuscin-positive group. There was also a significant difference between the 2 groups in tumor volume, degree of capsular invasion, and positive margins. The difference in seminal vesicle invasion and vascular invasion between the 2 groups was not statistically significant. Lipofuscin in prostatic adenocarcinoma correlates with both lower Gleason score and pathologic stage. Lipofuscin probably indicates slow cellular turnover as suggested by the low proliferation rate and p53 expression. The value of lipofuscin in biopsy as a predictor separating aggressive from indolent disease needs further investigation.

Anti-cytokeratin 20 staining of Merkel cells helps differentiate basaloid proliferations overlying dermatofibromas from basal cell carcinoma.

BACKGROUND: Basaloid epidermal proliferations (BEP), morphologically resembling basal cell carcinoma (BCC), have been described overlying dermatofibromas. Distinguishing the two is important because of non-aggressiveness of BEP and local aggressiveness of BCC. The aim of this study is to determine whether CK20 antibody staining for Merkel cells can be used as an adjunct method to differentiate BEP from BCC. METHODS: Ten cases of BEP overlying dermatofibromas were selected. Ten cases of BCC were used as control. The two groups were stained with CK20 antibody. Numerical density of CK20 stained Merkel cells in peri-lesional epidermis, BEP and BCC was determined by examining 300 cells at 400X in two separate areas by three independent pathologists. To determine statistical significance, the results were compared using t-test method. RESULTS: Density of Merkel cells in peri-lesional epidermis was 0.2-0.3%. No merkel cells were detected in the BCC. BEP overlying dermatofibromas showed an obvious increase in CK 20 stained Merkel cells. The difference was statistically significant (P < 0.02) CONCLUSIONS: We report a significant increase in CK20 stained Merkel cells in BEP overlying dermatofibromas as compared to BCC. CK20 antibody staining for Merkel cells can be used as an adjunct method to differentiate BEP overlying dermatofibromas from BCC. Mahmoodi M, Asad H, Salim S, Kantor G, Minimo C. Anti-CK20 staining of Merkel cells helps differentiate basaloid proliferations overlying dermatofibromas from basal cell carcinoma.

Renal siderosis in donor allograft: pathologic and clinical sequelae.

Transplantation of a cadaver kidney with marked siderosis and its outcome has not been reported. Increasing use of marginal kidneys has become common practice to expand the donor pool to meet the growing demand and will lead to increased recognition of kidney disease in cadaver donors with an unknown effect on graft outcome. This is a case report of a recipient of a cadaver kidney with marked siderosis monitored by surveillance biopsies and evaluated by clinico-pathological correlation. The recipient continued to have transplant kidney function, and a surveillance biopsy shows the natural course of the pathologic resolution of renal siderosis.