Adipophilin expression in sebaceous tumors and other cutaneous lesions with clear cell histology: an immunohistochemical study of 117 cases

Lipid droplets provide metabolic flexibility for cancer progression

A hallmark of cancer cells is their remarkable ability to efficiently adapt to favorable and hostile environments. Due to a unique metabolic flexibility, tumor cells can grow even in the absence of extracellular nutrients or in stressful scenarios. To achieve this, cancer cells need large amounts of lipids to build membranes, synthesize lipid-derived molecules, and generate metabolic energy in the absence of other nutrients. Tumor cells potentiate strategies to obtain lipids from other cells, metabolic pathways to synthesize new lipids, and mechanisms for efficient storage, mobilization, and utilization of these lipids. Lipid droplets (LDs) are the organelles that collect and supply lipids in eukaryotes and it is increasingly recognized that the accumulation of LDs is a new hallmark of cancer cells. Furthermore, an active role of LD proteins in processes underlying tumorigenesis has been proposed. Here, by focusing on three major classes of LD-resident proteins (perilipins, lipases, and acyl-CoA synthetases), we provide an overview of the contribution of LDs to cancer progression and discuss the role of LD proteins during the proliferation, invasion, metastasis, apoptosis, and stemness of cancer cells.

Androgen Receptor Immunohistochemistry is Superior to PRAME for the Differentiation of Sebaceous Carcinoma From Primary Cutaneous Basaloid Mimics

ABSTRACT

Cutaneous sebaceous neoplasia comprises a spectrum of disease ranging from benign adenomas to malignant carcinomas. The hallmark of these lesions is sebaceous differentiation. However, poorly-differentiated sebaceous carcinoma (SC), which lacks significant overt sebaceous differentiation, can show morphologic overlap with a variety of other basaloid cutaneous neoplasms. The accurate classification of SC is essential not only for diagnosis, but also because of the potential association with Muir-Torre syndrome. Androgen receptor (AR) is a sensitive, but not entirely specific immunohistochemical marker that has been used for the diagnosis of SC. PReferentially expressed Antigen in MElanoma (PRAME) demonstrates strong cytoplasmic labeling of mature sebocytes and has been reported to be expressed in a variety of sebaceous neoplasms, including in the basaloid cell component. Therefore, we sought to compare the diagnostic use of cytoplasmic PRAME expression with that of AR for the distinction of SC from a cohort of basaloid cutaneous mimics; namely basal cell carcinoma, basaloid squamous cell carcinoma, pilomatricoma, cutaneous lymphadenoma, and extra-mammary Paget disease. We report that cytoplasmic PRAME expression is uncommon in poorly differentiated SC, and although specific, it shows very low sensitivity (22%). In contrast, AR was moderately sensitive (66%) and highly specific (92%) for the distinction of SC from basaloid mimics. These attributes, in addition to the nuclear expression of AR in the sebocytic and basaloid components of SC, suggest that AR is superior to PRAME for the diagnosis of SC.

HPV-associated Vulvar Intraepithelial Carcinoma With Sebaceous Differentiation: Report of 2 Cases

Sebaceous carcinoma (SC) is a malignant neoplasm demonstrating sebocytic differentiation, commonly in the periocular area. Sebocytic differentiation is recognized by multivesicular cytoplasmic clearing with frequent nuclear scalloping. The vesicles can be highlighted by immunohistochemical stains against the perilipin family proteins including adipophilin. Extraocular SC is uncommon but well reported, often in the setting of Muir-Torre syndrome; however, vulvar SC is exceptionally rare. The literature review yielded only 12 prior cases of vulvar SC, all of which showed invasion. Here we report 2 additional similar cases from 2 different institutions of an intraepithelial carcinoma with sebaceous differentiation. Histologic examination of multiple specimens from both patients showed similar features: a multifocal intraepithelial basaloid nodular neoplasm sparing the basal layer with occasional pagetoid spread. The tumor cells demonstrated a high nuclear to cytoplasmic ratio, mitoses, variably foamy vacuolated cytoplasm, and nuclear indentation. Multiple specimens from both patients showed evidence of sebaceous differentiation (substantiated by adipophilin positivity in a membranous vesicular pattern in case 1 and by androgen receptor and epithelial membrane antigen positivity in case 2), and squamous differentiation (substantiated by p63/p40 and weak CK 5/6 expression), as well as human papillomavirus (HPV) association (substantiated by p16 block positivity and detection of high-risk HPV by in situ hybridization). One case was a true in situ lesion without evidence of invasion, and the other case was predominantly an in situ carcinoma with prominent adnexal extension and focal superficial invasion of <1 mm seen in one of multiple specimens. To our knowledge, these 2 cases are the first to show a vulvar SC/carcinoma with sebaceous differentiation that is predominantly limited to the epidermis, and the first documentation of HPV infection in vulvar sebaceous neoplasms. Vulvar intraepithelial carcinoma with sebaceous differentiation is the umbrella term we chose for this entity. Whether this is a true SC in situ that is HPV positive/driven, or a vulvar intraepithelial neoplasia with sebaceous differentiation, is not entirely clear. We emphasize the importance of looking for this morphology to avoid misclassification. Due to the rarity of cases, optimal treatment at this site has not been established.

Pagetoid Spread in Basal Cell Carcinoma: Potential for Misdiagnosis

ABSTRACT

Basal cell carcinomas are one of the most common cutaneous carcinomas and show classical histologic features of basaloid nests with peripheral palisading. Pagetoid and intraepidermal spread has not been described in basal cell carcinoma to the best of our knowledge. We report 5 cases of basal cell carcinoma with classic histologic patterns and overlying basaloid nests and single intraepidermal tumor cells. A panel of immunostains were performed that included CK7, MOC31, CEA-m, EMA, androgen receptor, and Bcl2. Most of our cases were positive for both MOC31 and CK7, and all cases were negative for CEA-m and EMA excluding extramammary Paget disease, one of the most common differential diagnoses. These cases expand the spectrum of findings that can be seen in basal cell carcinoma and can help prevent misdiagnoses of basal cell carcinomas as more aggressive tumors.

Adipophilin: roles in physiology and pathology

Adipophilin (ADRP/ADPH/PLIN2), an adipocyte differentiation-related protein, is highly expressed at a very early time during the differentiation of adipocytes. It assists in the formation and maintenance of intracellular lipid droplets and plays a role in regulating the physiological functions of the body. More and more studies indicate that it is involved in the occurrence and development of a variety of glycolipid metabolic diseases and tumours. In this review, we comprehensively stated the expression and functions of adipophilin and introduced its roles in physiology and pathology.

Diagnostic Accuracy of GATA6 Immunostaining in Sebaceous Tumors of the Skin

The accurate diagnosis of skin adnexal neoplasms is sometimes challenging but is necessary because medical management and follow-up may differ between tumors. GATA6 transcription factor has been identified as a new marker of the upper folliculosebaceous compartment (lower infundibulum, junctional zone and isthmus, and upper sebaceous gland) in the human skin. We aimed to determine the diagnostic accuracy of GATA6 immunostaining to diagnose sebaceous tumors compared with that to diagnose other adnexal and nonadnexal cutaneous neoplasms. We conducted a retrospective, evaluator-nonblinded study comparing the reference standard (diagnosis by an expert dermatopathologist) with GATA6 immunostaining to identify sebaceous tumors in a cohort containing 234 different tumors. The GATA6 expression score was significatively higher in sebaceous than that in nonsebaceous tumors. In addition, tumors originating from the upper hair follicle showed positive results for GATA6 staining; however, they showed lower GATA6 expression scores. Detection of sebaceous tumors using GATA6 positivity had a sensitivity of 95.7% (95% confidence interval [95% CI], 85.8-99.2), specificity of 80.8% (95% CI, 74.5-85.8), positive predictive value of 55.6% (95% CI, 44.7-65.9), and negative predictive value of 98.7% (95% CI, 95.4-99.8). GATA6 showed similar sensitivity to adipophilin, the reference marker; however, the specificity of GATA6 was higher, as observed in a cohort of 106 tumors enriched in squamous cell carcinomas with clear-cell histology. In addition, GATA6 positivity was assessed in 39 sebaceous carcinomas and compared with epithelial membrane antigen (EMA), CK7, and androgen receptor (AR) staining results. Although CK7 staining displayed lower diagnostic performances, GATA6 staining showed comparable results as EMA and AR. Finally, we found GATA6 expression in skin metastases of gastrointestinal origin, whereas GATA6 was absent in metastases originating from breast or lung cancers. Overall, our work identified GATA6 immunostaining as a new diagnostic tool for sebaceous tumors.

Sebaceous Carcinoma Arising in Ovarian Teratoma: First Report Associated With Germline Mismatch Repair Gene Mutation

Sebaceous carcinoma is an uncommon primary cutaneous neoplasm which may be associated with mismatch repair (MMR) abnormalities and sometimes with Muir-Torré syndrome. These neoplasms rarely arise in the ovary within a teratoma/ dermoid cyst. We report a sebaceous carcinoma arising in an ovarian teratoma in a 49-yr old (the 14th case reported in the literature) which exhibited loss of expression of MMR proteins MSH2 and MSH6. A germline mutation c.1102C>T was present in exon 7 of the MSH2 gene, the first report of a germline mutation associated with this tumor type. In reporting this case, we review prior reports of primary ovarian sebaceous carcinoma. We recommend that all sebaceous carcinomas of the ovary undergo immunohistochemistry for MMR proteins for investigation of possible Lynch syndrome.

Mass Spectrometry-Based Proteomics of Human Milk to Identify Differentially Expressed Proteins in Women with Breast Cancer versus Controls

It is thought that accurate risk assessment and early diagnosis of breast cancer (BC) can help reduce cancer-related mortality. Proteomics analysis of breast milk may provide biomarkers of risk and occult disease. Our group works on the analysis of human milk samples from women with BC and controls to investigate alterations in protein patterns of milk that could be related to BC. In the current study, we used mass spectrometry (MS)-based proteomics analysis of 12 milk samples from donors with BC and matched controls. Specifically, we used one-dimensional (1D)-polyacrylamide gel electrophoresis (PAGE) coupled with nanoliquid chromatography tandem MS (nanoLC-MS/MS), followed by bioinformatics analysis. We confirmed the dysregulation of several proteins identified previously in a different set of milk samples. We also identified additional dysregulations in milk proteins shown to play a role in cancer development, such as Lactadherin isoform A, O-linked N-acetylglucosamine (GlcNAc) transferase, galactosyltransferase, recoverin, perilipin-3 isoform 1, histone-lysine methyltransferase, or clathrin heavy chain. Our results expand our current understanding of using milk as a biological fluid for identification of BC-related dysregulated proteins. Overall, our results also indicate that milk has the potential to be used for BC biomarker discovery, early detection and risk assessment in young, reproductively active women.

Cutaneous Sebaceous Carcinoma Presenting as a Large Fungating Breast Tumour in Synchronicity With Primary Carcinomata of the Breasts

Sebaceous carcinomas are rare malignant tumours which arise from sebaceous glands. They are subclassified into ocular and extraocular subtypes and most commonly occur in the head and neck region. Tumours below the neck occur infrequently, and most commonly resemble benign skin lesions such as pyogenic granulomata and molluscum contagiosum, or malignant skin tumours like basal and squamous cell carcinomas (SCCs). We report a case of an 86-year-old lady presenting with a fungating breast tumour which began as a “mole” and exhibited insidious growth over five years to reach a maximum size of 10 cm. An excision biopsy was performed by the breast surgery team and histopathological analysis revealed a sebaceous carcinoma arising from the skin adnexa. On subsequent follow up, the patient was found to have a 19 mm mass in the left breast and a 20 mm mass in the right breast, which was P5 and P3 on clinical palpation, respectively. Core biopsies of left and right breast lesions showed invasive lobular carcinoma and invasive ductal carcinoma with lobular features respectively; the patient was started on primary letrozole treatment. The patient also went on to have a 2 cm wide local excision of the sebaceous carcinoma scar which was excised down to the pectoralis fascia. This is a unique presentation of a sebaceous gland carcinoma presenting as a fungating breast tumour. These tumours have a high metastatic potential and local recurrence rate, and can co-exist with primary carcinoma of the breast.

Perilipins at a glance

Lipid droplets (LDs) are ubiquitous organelles that store and supply lipids for energy metabolism, membrane synthesis and production of lipid-derived signaling molecules. While compositional differences in the phospholipid monolayer or neutral lipid core of LDs impact their metabolism and function, the proteome of LDs has emerged as a major influencer in all aspects of LD biology. The perilipins (PLINs) are the most studied and abundant proteins residing on the LD surface. This Cell Science at a Glance and the accompanying poster summarize our current knowledge of the common and unique features of the mammalian PLIN family of proteins, the mechanisms through which they affect cell metabolism and signaling, and their links to disease.

A Comprehensive Commentary on the Multilocular Cystic Renal Neoplasm of Low Malignant Potential: A Urologist’s Perspective

Multilocular cystic renal neoplasm of low malignant potential (MCRNLMP) is a cystic renal tumor with indolent clinical behavior. In most of cases, it is an incidental finding during the examination of other health issues. The true incidence rate is estimated to be between 1.5% and 4% of all RCCs. These lesions are classified according to the Bosniak classification as Bosniak category III. There is a wide spectrum of diagnostic tools that can be utilized in the identification of this tumor, such as computed tomography (CT), magnetic resonance (MRI) or contrast-enhanced ultrasonography (CEUS). Management choices of these lesions range from conservative approaches, such as clinical follow-up, to surgery. Minimally invasive techniques (i.e., robotic surgery and laparoscopy) are preferred, with an emphasis on nephron sparing surgery, if clinically feasible.

Lipid Droplet Accumulation Independently Predicts Poor Clinical Prognosis in High-Grade Serous Ovarian Carcinoma

Simple Summary

High-grade serous carcinoma (HGSOC) is the most aggressive subtype of ovarian cancer and accounts for the vast majority of advanced stage cases. Intracellular accumulation of lipids as lipid droplets has been recognized as one of the characteristics of cancers and implicated in poor prognosis of several cancers, such as human melanomas. Here, we investigated the relationship between prognosis and lipid accumulation in HGSOC, and found that enhanced lipid accumulation in HGSOC tissues significantly correlated with poor prognosis. In cell-based assays with human ovarian cancer cells, we provide evidence that aerobic glycolysis, which is one of the characteristic metabolic abnormalities in cancer, induced lipid accumulation within cancer cells and targeting the lipid accumulation could suppress cancer cell proliferation. Thus, our results propose abnormal lipid accumulation as a negative indicator of HGSOC prognosis and a novel therapeutic target.

Abstract

High-grade serous ovarian carcinoma (HGSOC) is an epithelial cancer that accounts for most ovarian cancer deaths. Metabolic abnormalities such as extensive aerobic glycolysis and aberrant lipid metabolism are well-known characteristics of cancer cells. Indeed, accumulation of lipid droplets (LDs) in certain types of malignant tumors has been known for more than 50 years. Here, we investigated the correlation between LD accumulation and clinical prognosis. In 96 HGSOC patients, we found that high expression of the LD marker adipophilin was associated with poor progression-free and overall survival (p = 0.0022 and p = 0.014, respectively). OVCAR-3 ovarian carcinoma cells accumulated LDs in a glucose-dependent manner, which suggested the involvement of aerobic glycolysis and subsequently enhanced lipogenesis, with a result being LD accumulation. The acyl-CoA: cholesterol acyltransferase 1 inhibitor K604 and the hydroxymethylglutaryl-CoA reductase inhibitor pitavastatin blocked LD accumulation in OVCAR-3 cells and reduced phosphorylation of the survival-related kinases Akt and ERK1/2, both of which have been implicated in malignancy. Our cell-based assays thus suggested that enhanced aerobic glycolysis resulted in LD accumulation and activation of survival-related kinases. Overall, our results support the idea that cancers with lipogenic phenotypes are associated with poor clinical prognosis, and we suggest that adipophilin may serve as an independent indicator of a poor prognosis in HGSOC.

Clear Cell Proliferations of the Skin: A Histopathologic Review

ABSTRACT

Cutaneous clear cell proliferations encompass a heterogenous group of several primary cutaneous neoplasms and metastatic tumors with different histogenesis. Many of these clear cell proliferations may seem strikingly similar under the microscope resulting in challenging diagnosis. In many of these clear cell lesions, the reason for the clear or pale appearance of proliferating cells is unknown, whereas in other ones, this clear cell appearance is due to intracytoplasmic accumulation of glycogen, mucin, or lipid. Artifacts of tissue processing and degenerative phenomenon may also be responsible for the clear cell appearance of proliferating cells. Awareness of the histopathologic findings as well as histochemical and immunohistochemical techniques are crucial to the accurate diagnosis. This review details the histopathologic features of clear cell cutaneous proliferations, classifying them according their type of differentiation and paying special attention to the histopathologic differential diagnosis among them.

Perilipin 1 and adipophilin immunoexpression suggests the presence of lipid droplets in tooth germ, ameloblastoma, and ameloblastic carcinoma

BACKGROUND

Increased lipogenesis and lipid droplet accumulation are observed in diverse tumors, and these processes are associated with poor prognosis in several tumors, representing potential therapeutic targets. The presence of lipid droplets in odontogenic tissues and/or tumors is unknown.

METHODS

Immunohistochemistry for perilipin 1 and adipophilin was performed in 12 human tooth germs (TG), 27 conventional ameloblastoma (AM), and 8 ameloblastic carcinoma (AC) samples. Cytoplasmic staining was analyzed using an immunoreactive score (IRS), and the results were compared for the TG, AM, and AC samples by Kruskal-Wallis test followed by Dunn's post-test and confirmed by Mann-Whitney U test.

RESULTS

Perilipin 1 was negative in 91.7% of the TG samples, positive in 48.2% of the AM samples, and positive in 87.5% of the AC samples. Adipophilin was positive in 100% of the TG samples, 92.6% of the AM samples, and 100% of the AC samples. The perilipin 1 and adipophilin IRS revealed statistically significant differences between the TG, AM, and AC samples (p = .007 and p = .018, respectively). The perilipin 1 levels among the TG and AC samples were statically significant (**p = .0085), as well as the adipophilin levels when TG and AM samples were compared (**p < .0029).

CONCLUSIONS

Adipophilin exhibits significant activity in human tooth development. The immunoexpression of perilipin 1 and adipophilin in the AM and AC samples suggests the presence of lipid droplets, providing further evidence of metabolic alterations in these tumors. Additional studies with larger samples and alternative techniques are necessary to confirm these findings.

Adipophilin expression in skin lesions with clear cell histology

AIMS

Clear cells formed due to depositions of glycogen or lipids in the cytoplasm commonly occur in various tissues. Adipophilin (ADP), a lipid regulatory protein, is closely related to lipid droplets. This study aims to examine adipophilin expression in clear cells of various skin lesions.

METHODS

ADP expression was examined using immunohistochemistry in 108 sections from 15 skin lesion types with clear cell histology, namely, sebaceoma (n=16), sebaceous adenoma (n=3), sebaceous carcinoma (n=12), xanthomata cutis (n=10), xanthogranuloma (n=8), Paget's disease (n=10), Bowen disease (n=10), hidradenoma (n=9), atypical lipoma (n=5), superficial lipomatous nevus (n=5), metastatic renal cell carcinoma (n=5), squamous cell carcinoma (n=4), seborrheic keratosis (n=4), dermatofibroma (n=4) and clear cell sarcoma (n=3).

RESULTS

ADP was not expressed in Bowen disease, hidradenoma or seborrheic keratosis. Four expression patterns, foamy, reticular, granular and punctate, were summarised based on their expression in clear cells. Different expression patterns were related to tissue origin and differentiation degree. Foamy expression was commonly observed in lesions with mature sebaceous glands and xanthomas; reticular expression in adipocytes; granular expression in xanthoma, xanthogranuloma and metastatic renal carcinoma and punctate expression in sebaceoma, sebaceous carcinoma, Paget's disease, squamous cell carcinoma and clear cell sarcoma. Furthermore, stronger staining with focal vesicular labelling was noted in sebaceoma than in sebaceous carcinoma. Characteristic labelling was noted, including the circular distribution in Touton giant cells of xanthogranulomas and focal distribution in the clear cells along the edge of necrotic tissue in clear cell sarcoma.

CONCLUSIONS

ADP is useful in identifying intracytoplasmic lipids and can be used to diagnose skin lesions with clear cell histology, especially in some lesions with characteristic labelling.

Comparison of adipophilin and recently introduced PReferentially expressed Antigen in MElanoma immunohistochemistry in the assessment of sebaceous neoplasms: A pilot study

BACKGROUND

We and others have noticed consistent staining of sebaceous glands with PReferentially expressed Antigen in MElanoma (PRAME). We aimed to determine whether PRAME was as sensitive, specific, and interpretable as adipophilin for distinguishing sebaceous neoplasms (SNs) from other neoplasms.

METHODS

Twenty SNs and 32 control cases were stained for PRAME and adipophilin. Extent of staining was scored as follows: 0, no staining; 1, <5% positivity; 2, 5% to 50% positivity; and 3, >50% positivity. Intensity was scored as negative, weak, moderate, or strong. A composite score was determined by adding the scores for extent and intensity.

RESULTS

PRAME had positive composite scores in all 20 SNs in the more differentiated areas, whereas adipophilin had positive composite scores in 19/20 cases. PRAME showed positivity in the basaloid cells in 15/16 cases, whereas adipophilin was positive in 14. Among controls, PRAME and adipophilin had positive composite scores in 3/32 cases and 6/32 cases, respectively.

CONCLUSIONS

PRAME and adipophilin are comparable in terms of distribution and intensity for staining sebocytes. In the basaloid cells, PRAME expression is often more diffuse and easier to detect than adipophilin. In comparing the SNs to the controls, PRAME was more sensitive and more specific than adipophilin. PRAME could be used as an additional marker of sebaceous differentiation in everyday practice.

Sebaceous carcinoma of the vulva treated with sentinel lymph node biopsy: a case report and literature review

Sebaceous carcinoma (SC) is a rare and aggressive cutaneous malignancy. It often occurs on the eyelid, where it is called periocular SC, while extraocular SC mainly occurs on the head and heck. Extraocular vulvar SC is extremely rare; only nine cases have been described in the literature, and the optimal treatment strategy is unknown. We herein report a case of vulvar SC that was successfully treated with local excision in combination with sentinel lymph node biopsy (SNB). A 66-year-old female presented with vulvar discomfort. An 8 mm ulcerated mass was palpable in her left labia minora. Skin biopsy suggested SC. Imaging showed no swelling of the pelvic and inguinal lymph nodes and no metastasis. Sentinel lymph node scintigraphy using technetium-99 m showed three sentinel lymph nodes. The patient underwent local excision with SNB; intraoperative frozen-section examination revealed no nodal metastasis, and no further inguinal lymphadenectomy was performed. The final diagnosis was SC of the vulva, FIGO stage IB (pT1bN0M0). At the 14-month follow-up, she remained asymptomatic and had no signs of recurrence. The scientific rationale for SNB in extraocular SC has not yet been established, although SNB can be considered for periocular SC. However, considering the insufficient data on the management of vulvar SC and the aggressive nature of both periocular and extraocular SCs, SNB can be a reasonable and useful method for avoiding inadequate treatment and reducing the complications caused by unnecessary inguinal lymphadenectomy.

Advanced age heightens hepatic damage in a murine model of scald burn injury

BACKGROUND

Elderly burn patients exhibit a lower survival rate compared with younger counterparts. The liver is susceptible to damage after burn injury, which predisposes to poor outcomes. Lipid homeostasis and the antioxidant glutathione system play fundamental roles in preserving liver integrity. Herein, we explored changes in these major pathways associated with liver damage in the aging animals after burn injury.

METHODS

We compared liver enzymes, histology, lipid-peroxidation, and glutathione-metabolism profiles from young and aged female mice after a 15% total body surface area burn. Mice were euthanized at 24 hours after injury, and livers and serum were collected.

RESULTS

Aged burn animals exhibited elevated (p < 0.05) aspartate aminotransferase and alanine aminotransferase levels and increased inflammatory cell infiltration, edema, and necrosis compared with their younger counterparts. The percentage of adipophilin-stained area in livers from young sham, young burn, aged sham, and aged burn groups was 10%, 44%, 16%, and 78% (p < 0.05), respectively. Liver malondialdehyde levels were 1.4 ± 0.5 nmol/mg, 2.06 ± 0.2 nmol/mg, 1.81 ± 0.12 nmol/mg, and 3.45 ± 0.2 nmol/mg (p < 0.05) in young sham, young burn, aged sham, and aged burn mice, respectively. Oxidized glutathione (GSSG) content increased 50% in the young burn, and 88% in aged burn animals compared with the young sham group (p < 0.05). The reduced glutathione GSH/GSSG ratio was significantly reduced by 54% in aged burn mice compared with young sham animals (p < 0.05). Furthermore, glutathione peroxidase gene expression showed a 96% decrease in the aged burn group compared with young sham mice (p < 0.05).

CONCLUSION

Aged burn animals exhibit severe liver damage from heightened lipid peroxidation and inadequate antioxidative response. The increased peroxidation is associated with abundant lipid deposits in hepatic tissue postburn and a weak antioxidative response due to hepatic glutathione peroxidase downregulation. Further studies will focus on the functional significance of these findings concerning hepatic homeostasis.

Ocular Adnexal Adenomatoid Sebaceous Gland Hyperplasia: A Clinical and Immunopathologic Analysis in Relation to the Muir-Torre Syndrome

The purpose of this study is to codify the microscopic diagnostic criteria for ocular adnexal brow and caruncular sebaceous gland hyperplasias (pseudoadenomatoid) that distinguish it from an adenoma. Clinical records and photographs were critically reviewed and microscopic slides were stained with hematoxylin and eosin and immunochemically stained for adipophilin, androgen receptor, p16, p53, a spectrum of cytokeratins, Ki-67 and mismatch repair nuclear protein expression for MLH1, MSH2, PMS2, and MSH6. The patients and their close relatives had no history of cancer. Cytokeratin 7 and especially cytokeratin 17 highlighted the presence of ducts in the hyperplastic lesion, which are not present in adenomas. p16 and p53 were negative and Ki-67 immunostaining demonstrated similar low proliferation indices for normal and hyperplastic glands. The mismatch repair nuclear protein expressions were preserved in both lesions. Histopathologic misdiagnosis of adenomatoid sebaceous gland hyperplasia as an adenoma can lead to the impression of an association with the Muir-Torre syndrome. Cytokeratins 7 and 17 immunostaining can be helpful in highlighting compressed ducts that in exuberant sebaceous gland hyperplasias may lead to a diagnosis of an adenoma (in which ducts are absent). Negative immunostaining for p16 rules out a possible etiologic role of human papillomavirus in hyperplasias and the negative p53 staining indicates the lesions are not truly neoplastic. The preservation of mismatch repair nuclear protein expression rules out the likelihood of the Muir-Torre syndrome. The current cases convincingly establish that sebaceous hyperplasia is not associated with the Muir-Torre syndrome by both clinical findings and immunohistochemical testing.Two yellow lesions, from the brow and caruncle, were examined microscopically and immunohistochemically to establish the diagnosis of sebaceous gland hyperplasia and to rule out the Muir-Torre syndrome.

Sebaceous Carcinoma Incidence and Survival Among Solid Organ Transplant Recipients in the United States, 1987-2017

Importance

Risk of sebaceous carcinoma (SC), a rare skin cancer associated with Muir-Torre syndrome, is elevated among solid organ transplant recipients (SOTRs). However, population studies evaluating this association and assessing survival for posttransplant cases are lacking, and further understanding of SC epidemiology in this immunosuppressed population could provide etiologic and clinical insights.

Objective

To assess SC incidence and patient survival after solid organ transplantation.

Design, Setting, and Participants

This cohort study, conducted from January 1, 1987, to December 31, 2017, used data from the Transplant Cancer Match Study, which links transplant and cancer registry data for 17 states and 1 metropolitan area in the United States. Altogether, these registries account for approximately 46% of all US transplants. Data on demographic and transplant characteristics as well as induction and initial maintenance immunosuppressive therapies were obtained from the transplant registry. Standardized incidence ratios (SIRs) comparing SC incidence among SOTRs to the general population were calculated. Incidence rate ratios (IRRs) comparing SC risk between SOTR subgroups were calculated using multivariate Poisson regression. Cox regression was used to compare overall survival between SC cases in SOTRs and other individuals.

Main Outcomes and Measures

Sebaceous carcinoma incidence and overall patient survival after transplantation compared with the general population.

Results

A total of 326 282 transplant procedures were performed for 301 075 patients (No. [%] age at transplant, 126 550 [38.8%] aged 0-44 years; 82 394 [25.3%] aged 45-54 years; 82 082 [25.5%] aged 55-64 years; 35 256 [10.8%] aged ≥65 years; 201 354 male patients [61.7%]; 202 557 White patients [62.1%]). A total of 102 SCs were diagnosed in 301 075 SOTRs, corresponding to a 25-fold increased incidence (SIR, 24.8; 95% CI, 20.2-30.1). Incidence was especially elevated among lung recipients (SIR, 47.7; 95% CI, 20.6-94.0) and after a posttransplant diagnosis of cutaneous squamous cell carcinoma (SIR, 104.0; 95% CI, 62.8-163.0). Among SOTRs, factors independently associated with SC risk included male sex (IRR, 2.46; 95% CI, 1.48-4.07; P < .001), race/ethnicity (non-Hispanic Black vs non-Hispanic White, IRR, 0.28; 95% CI, 0.10-0.77; P = .01), older age (IRR, 7.85; 95% CI, 3.85-16.0; ≥65 vs 0-44 years; P < .001 for trend), use of thymoglobulin induction (IRR, 1.82; 95% CI, 1.16-2.86; P = .009), posttransplant cutaneous squamous cell carcinoma (IRR, 4.60; 95% CI, 2.67-7.94; P < .001), and longer time since transplant (IRR, 8.40; 95% CI, 3.94-17.90; ≥10 vs 0-1.9 years; P < .001 for trend). Muir-Torre syndrome-associated cancers were rare among both SOTRs and others with SC (3.3%-4.1%). Among patients with SC, prior transplantation was associated with increased overall mortality (adjusted hazard ratio, 2.09; 95% CI, 1.45-3.01), although few deaths were attributed to SC (4 of 92 SOTRs [4.3%]; 235 of 3585 non-SOTRs [6.6%]).

Conclusions and Relevance

Among SOTRs, results of this large cohort study suggest that SC was associated with measures of immunosuppression, and overall survival was worse than for other patients with SC. Findings also suggest a possible role for UV radiation in carcinogenesis.

ADFP promotes cell proliferation in lung adenocarcinoma via Akt phosphorylation

Previously, we identified differentially expressed proteins, including ADFP, between lung adenocarcinoma (LAC) tissue and paired normal bronchioloalveolar epithelium. In this study, we investigated the role of ADFP in LAC. ADFP levels in the serum of patients with lung cancer and benign diseases were measured by enzyme‐linked immunosorbent assays (ELISA). shRNA was used to knock‐down or overexpress ADFP in A549 and NCI‐H1299 cells. The biological function of ADFP and its underlying mechanisms was evaluated in vivo and in vitro. ADFP was highly expressed in the serum of lung cancer patients, especially those with LAC. ADFP promoted cell proliferation and up‐regulated the p‐Akt/Akt ratio in A549 and NCI‐H1299 cells in vitro. Furthermore, in nude mice, ADFP promoted tumour formation with high levels of p‐Akt/Akt, Ki67 and proliferating cell nuclear antigen (PCNA). Similar to the effect of ADFP knock‐down, MK‐2206 (a phosphorylation inhibitor of Akt) reduced A549 and NCI‐H1299 cell proliferation. In ADFP‐overexpressing A549 and NCI‐H1299 cells, proliferation was suppressed by MK‐2206 and returned to the control level. ADFP did not regulate invasion, migration or adhesion in LAC cells. Together, these results suggest that ADFP promotes LAC cell proliferation in vitro and in vivo by increasing Akt phosphorylation level.

Adipophilin expression in cutaneous malignant melanoma is associated with high proliferation and poor clinical prognosis

Adipophilin (ADP) is a primary protein component of lipid droplets (LDs). For more than half a century, certain types of cancer cells have been known to contain LDs in their cytoplasm. However, the pathological significance of ADP or LDs in cancer remains unclear. In the present study, we investigated the association between ADP and other pathological characteristics in cutaneous malignant melanomas to clarify the role of ADP in melanoma cells. We immunostained whole paraffin sections of primary cutaneous melanomas obtained from 90 cases for ADP, after which we analyzed the correlation between ADP immunohistochemistry (IHC) and patient survival data. We also studied the relationship between the ADP IHC score and in situ hybridization (ISH) score of ADP mRNA, and the Ki67-labeling index (Ki67-LI) by using tissue microarrays consisting of 74 primary cutaneous malignant melanomas, 19 metastasizing melanomas, and 29 melanocytic nevi. Finally, we analyzed the relationship between ADP expression and cell proliferation in cutaneous melanoma cell lines. We found that high ADP expression was associated with poor metastasis-free survival, disease-specific survival, and overall survival rates of patients with cutaneous melanomas (P < 0.05). By linear regression analysis, ADP IHC was correlated with increasing ADP mRNA ISH H-scores and Ki67-LI scores in melanocytic lesions (P < 0.01). ADP IHC and ADP ISH H-scores and Ki67-LI scores were greater in pT3-4 melanomas than in pT1-2 melanomas. In cell-based assays, cells with increased ADP expression showed higher proliferation rates compared with those of low-ADP cells. Thus, ADP expression in malignant melanoma was significantly associated with high cell proliferation and poor clinical prognosis. Our results thus indicate a significant association between ADP and melanoma progression, and we propose that ADP may be a novel marker of aggressive cutaneous melanoma with a lipogenic phenotype.

Update on the pathology, genetics and somatic landscape of sebaceous tumours

Cutaneous sebaceous neoplasms show a predilection for the head and neck area of adults and include tumours with benign behaviour, sebaceous adenoma and sebaceoma, and sebaceous carcinoma with potential for an aggressive disease course at the malignant end of the spectrum. The majority of tumours are solitary and sporadic, but a subset of tumours may be associated with Lynch syndrome, also known as hereditary non-polyposis colon cancer (HNPCC) and previously referred to as Muir-Torre syndrome (now known to be part of Lynch syndrome). This review provides an overview of the clinical and histological features of cutaneous sebaceous neoplasia with an emphasis on differentiating features and differential diagnosis. It also offers insights into the recently described molecular pathways involved in the development of sebaceous tumours and their association with Lynch syndrome.

The Utility of Perilipin in Liposarcomas: PLIN1 Differentiates Round Cell Liposarcoma From Other Round Cell Sarcomas

Liposarcoma is the most common soft tissue sarcoma in adults; however, accurate diagnosis often depends on the use of ancillary molecular testing which can be time consuming and expensive. Myxoid/round cell liposarcoma may be a diagnostic challenge due to the morphologic similarities with other nonadipocytic sarcomas with round cell morphology. Immunohistochemistry may be a helpful adjunct to appropriately triage cases for molecular testing. Perilipin 1 (PLIN1) and perilipin 2 (adipophilin) (PLIN2) are intracellular proteins involved in lipid droplet formation, which we hypothesized may be useful as immunohistochemical markers for liposarcoma. Using archival tumor tissue, we assessed pattern of PLIN1 and PLIN2 expression in 46 adipocytic tumors and 36 nonadipocytic sarcomas. PLIN1 was expressed in 88% of liposarcomas, including 100% of myxoid/round cell liposarcomas, and did not have any expression in nonadipocytic sarcomas. PLIN1 was not expressed in dedifferentiated liposarcoma. Although PLIN2 demonstrates increased sensitivity for liposarcoma, including expression in dedifferentiated liposarcoma, it is not specific for adipocytic differentiation and is expressed in other nonadipocytic sarcomas. Furthermore, PLIN2 is not expressed in lipoma-like well-differentiated liposarcoma, and as such has limited diagnostic utility.

Villous Sebaceous Adenoma Arising from the Caruncular Surface Squamous Epithelium

A 68-year-old woman developed an asymptomatic left caruncular multilobular lesion over one year. Excision of the lesion displayed a benign sebaceous neoplasm taking origin from the surface squamous epithelium which invaginated into the stroma to create crypts resembling the conjunctival pseudoglands of Henle or the glands of Lieberkuhn of the small intestine. Scattered sebaceous cells were also discovered in the surface squamous epithelium. The cryptal walls spawned lateral sebaceous gland lobules that were adipophilin positive. p16 was positive in the surface epithelium, the cryptal walls, and in the basal cells of the sebaceous lobules. No defects in nuclear mismatch repair protein expression were identified, which together with the absence of a familial cancer history, rendered unlikely an association with the Muir-Torre syndrome.

The clinicopathological significance of the adipophilin and fatty acid synthase expression in salivary duct carcinoma

Salivary duct carcinoma (SDC) is an aggressive, uncommon tumor histologically comparable to high-grade mammary ductal carcinoma. SDCs are usually androgen receptor (AR)–positive and often HER2-positive. Recently, therapies targeting these molecules for SDC have attracted attention. Lipid metabolism changes have been described in association with biological behavior in various cancers, although no such relationship has yet been reported for SDC. We therefore analyzed the clinicopathological relevance of the immunohistochemical expression of adipophilin (ADP) and fatty acid synthase (FASN), representative lipid metabolism–related proteins, in 147 SDCs. ADP and FASN were variably immunoreactive in most SDCs (both 99.3%), and the ADP and FASN expression was negatively correlated (P = 0.014). ADP-positive (≥ 5%) SDCs more frequently exhibited a prominent nuclear pleomorphism and high-Ki-67 labeling index than those ADP-negative (P = 0.013 and 0.011, respectively). In contrast, a high FASN score, calculated by the staining proportion and intensity, (≥ 120) was correlated with the high expression of AR and FOXA1 (P < 0.001 and = 0.003, respectively). The ADP and FASN expression differed significantly among the subtypes based on biomarker immunoprofiling, as assessed by the AR, HER2, and Ki-67 status (P = 0.017 and 0.003, respectively). A multivariate analysis showed that ADP-positive expression was associated with a shorter overall and progression-free survival (P = 0.018 and 0.003, respectively). ADP was associated with an aggressive histopathology and unfavorable prognosis, and FASN may biologically interact with the AR signaling pathway in SDC. ADP may, therefore, be a new prognostic indicator and therapeutic target in SDC.

Sebaceous carcinoma of the breast predominantly characterized by intraductal growth: a case report

Background

Sebaceous carcinoma (SC) is frequently classified as periocular or extraocular. Extraocular SC is rare and mainly occurs in the head and neck, the major salivary glands, or oral mucosa. SC of the breast, lung, and ovary is particularly rare, and the few cases of SC of the breast predominantly exhibit intraductal growth.

Case presentation

A 47-year-old Japanese woman was referred to our hospital with accumulated polymorphic calcification in the left breast which was detected using mammography. Ultrasonography revealed an irregular 13-mm mass in the left breast, and analysis of a core needle biopsy revealed noninvasive ductal carcinoma. Total mastectomy and sentinel lymph node biopsy were performed. Histopathology demonstrated that carcinoma in situ (CIS) represented a significant lesion, and the cytoplasm of tumor cells was clear with numerous minute vacuoles. Immunohistochemical analysis demonstrated that most tumor cells expressed adipophilin. Together, these findings led to a diagnosis of SC, mainly comprising CIS.

Conclusions

We encountered a rare case of SC of the breast with predominant CIS.

Lipid droplets: platforms with multiple functions in cancer hallmarks

Lipid droplets (also known as lipid bodies) are lipid-rich, cytoplasmic organelles that play important roles in cell signaling, lipid metabolism, membrane trafficking, and the production of inflammatory mediators. Lipid droplet biogenesis is a regulated process, and accumulation of these organelles within leukocytes, epithelial cells, hepatocytes, and other nonadipocyte cells is a frequently observed phenotype in several physiologic or pathogenic situations and is thoroughly described during inflammatory conditions. Moreover, in recent years, several studies have described an increase in intracellular lipid accumulation in different neoplastic processes, although it is not clear whether lipid droplet accumulation is directly involved in the establishment of these different types of malignancies. This review discusses current evidence related to the biogenesis, composition and functions of lipid droplets related to the hallmarks of cancer: inflammation, cell metabolism, increased proliferation, escape from cell death, and hypoxia. Moreover, the potential of lipid droplets as markers of disease and targets for novel anti-inflammatory and antineoplastic therapies will be discussed.

Sebaceoma of a Meibomian Gland of the Upper Eyelid

Over a period of 1 year, a 74-year-old man slowly developed a painless left upper eyelid intratarsal mass. The skin was movable over the lesion. At surgery, a well-circumscribed, yellow-white, partially cystic tumor was encountered. Histopathologically it was composed of a random mixture of basaloid and sebaceous cells arranged in interconnecting cords. Immunohistochemical evaluation disclosed epithelial membrane antigen, adipophilin, and cytokeratin 14 positivity. These findings led to the diagnosis of a sebaceoma. The tumor cells abnormally failed to express mismatch repair proteins for MLH1 and PMS2. The patient did not have a personal history of any visceral malignancy, but his father had died at the age of 46 years and a daughter at the age of 33 years from colonic carcinomas. The implications of this periocular sebaceoma for the Muir-Torre syndrome are explored.

Cytologic Grading of Cutaneous Sebaceous Neoplasms: Does it Help to Differentiate Benign From Malignant?

Both architectural and cytologic characteristics are used to distinguish benign from malignant sebaceous neoplasms; however, specific cytopathologic features of sebocytes have not been well defined. The authors assessed architectural and cytological features of 63 sebaceous neoplasms [15 sebaceous hyperplasias, 12 sebaceomas, 16 sebaceous adenomas (SA), 14 sebaceous carcinomas (SC), and 6 ocular sebaceous carcinoma (OSC)] to investigate whether cytological grading may facilitate classification of lesions. Among other criteria, nuclear pleomorphism (size, nucleolar appearance, membrane irregularity, crowding, mitoses, and chromatin pattern) was assessed and 3 theoretical nuclear grades established. Immunohistochemistry for CK10, p16, adipophilin and ki67 was performed on 7 cases of each type of tumor. Most sebaceous neoplasms, except OSC, showed a bland architectural silhouette. However, SA, SC, and OSC revealed larger nuclei (≥14 μm in ≥50% of cases), evident to multiple nucleoli, membrane irregularity, coarse to clumped chromatin, and nuclear grade ≥2 (latter in ≥56% of cases); by contrast, sebaceous hyperplasia and sebaceomas showed smaller nuclei (≤10 μm in ≥50% of cases), smooth borders, inconspicuous nucleoli, fine chromatin, and grade 1 nuclei (latter in 100% of cases). In the setting of a well-circumscribed architecture, cytologic features gain importance in the classification of sebaceous neoplasms. Interestingly, cytologic similarities found in SA and SC may indicate a close relationship of both neoplasms.

Intraductal sebaceous papilloma of a meibomian gland: a new entity possibly associated with the MSH6 subtype of the Muir-Torre syndrome

Over several months, a painless, multinodular, non-erythematous swelling of the deep tissues of his left upper eyelid developed in a 63-year-old man. An excisional biopsy with histopathologic evaluation disclosed a unique sebaceous papilloma within a cyst lined by non-keratinizing squamous epithelium that focally displayed a variably thick, superficial, eosinophilic cuticular layer. Immunohistochemical staining demonstrated that the tumor and its epithelial cystic lining had a profile consistent with Meibomian gland duct epithelium. Adipophilin highlighted cytoplasmic vacuolar lipid positivity. The encapsulation of the lesion, absence of nuclear atypia, and Ki-67 nuclear positivity restricted to the basilar cells established its intrinsically benign nature. The patient's clinical history was remarkable for pulmonary and colonic carcinomas resected, respectively, 20 years and 8 years earlier. DNA mismatch repair protein expression studies disclosed loss of nuclear immunostaining of MSH6 protein, pointing to the possibility of an underlying rare MSH6 variant of the Muir-Torre syndrome, not yet described in the ophthalmic literature. p16 nuclear positivity was also found in the tumor cells, indicating the possible role of high-risk human papillomavirus as an additional factor in the genesis of the tumor. Genetic evaluation of normal and tumoral tissues in future similar cases will detect if there is an underlying germline mutation versus a somatic mutation limited to the tumor. This will be required to fully establish a predictable linkage with this new subtype of the Muir-Torre syndrome.

[Sebaceous carcinoma in situ in extraocular skin : Case report and discussion of the new entity]

Sebaceous carcinoma in situ (SCIS) is a rare intraepidermal neoplasia, mostly occurring on the eyelid and the face. Despite abundant literature on invasive sebaceous carcinoma, there are relatively few articles about SCIS. We report the case of 78-year-old woman suffering from SCIS of the left cheek, presenting as an erythematous skin lesion. The histological examination revealed intraepidermal and intraadnexal population of atypical cells with foamy cytoplasm and with immunohistochemical adipophilin-, cytokeratin-7- and EMA-positivity in the tumor cells.

Skin Adnexal Tumors in Plain Language: A Practical Approach for the General Surgical Pathologist

CONTEXT.—

Skin adnexal tumors, those neoplasms deriving from hair follicles and sweat glands, are often a source of confusion amongst even experienced pathologists. Many well-described entities have overlapping features, tumors are often only partially sampled, and many cases do not fit neatly into well-established classification schemes.

OBJECTIVES.—

To simplify categorization of adnexal tumors for the general surgical pathologist and to shed light on many of the diagnostic dilemmas commonly encountered in daily practice. The following review breaks adnexal neoplasms into 3 groups: sebaceous, sweat gland-derived, and follicular.

DATA SOURCES.—

Pathology reference texts and primary literature regarding adnexal tumors.

CONCLUSIONS.—

Review of the clinical and histopathologic features of primary cutaneous adnexal tumors, and the diagnostic dilemmas they create, will assist the general surgical pathologist in diagnosing these often challenging lesions.

Combinatorial Electrophoresis and Mass Spectrometry-Based Proteomics in Breast Milk for Breast Cancer Biomarker Discovery

Innovations in approaches for early detection and individual risk assessment of different cancers, including breast cancer (BC), are needed to reduce cancer morbidity and associated mortality. The assessment of potential cancer biomarkers in accessible bodily fluids provides a novel approach to identify the risk and/or onset of cancer. Biomarkers are biomolecules, such as proteins, that are indicative of an abnormality or a disease. Human milk is vastly underutilized biospecimen that offers the opportunity to investigate potential protein BC-biomarkers in young, reproductively active women. As a first step, we have examined the entire protein pattern in human milk samples from breastfeeding mothers with cancer, who were diagnosed either before or after milk donation, and from women without cancer, using mass spectrometry (MS)-based proteomics.

Proteomics analysis of human breast milk to assess breast cancer risk

Detection of breast cancer (BC) in young women is challenging because mammography, the most common tool for detecting BC, is not effective on the dense breast tissue characteristic of young women. In addition to the limited means for detecting their BC, young women face a transient increased risk of pregnancy-associated BC. As a consequence, reproductively active women could benefit significantly from a tool that provides them with accurate risk assessment and early detection of BC. One potential method for detection of BC is biochemical monitoring of proteins and other molecules in bodily fluids such as serum, nipple aspirate, ductal lavage, tear, urine, saliva and breast milk. Of all these fluids, only breast milk provides access to a large volume of breast tissue, in the form of exfoliated epithelial cells, and to the local breast environment, in the form of molecules in the milk. Thus, analysis of breast milk is a non-invasive method with significant potential for assessing BC risk. Here we analyzed human breast milk by mass spectrometry (MS)-based proteomics to build a biomarker signature for early detection of BC. Ten milk samples from eight women provided five paired-groups (cancer versus control) for analysis of dysregulatedproteins: two within woman comparisons (milk from a diseased breast versus a healthy breast of the same woman) and three across women comparisons (milk from a woman with cancer versus a woman without cancer). Despite a wide range in the time between milk donation and cancer diagnosis (cancer diagnosis occurred from 1 month before to 24 months after milk donation), the levels of some proteins differed significantly between cancer and control in several of the five comparison groups. These pilot data are supportive of the idea that molecular analysis of breast milk will identify proteins informative for early detection and accurate assessment of BC risk, and warrant further research. Data are available via ProteomeXchange with identifier PXD007066.

Regression of Sebaceous Carcinoma of the Eyelid after a Small Incisional Biopsy: Report of Two Cases

Purpose

To report 2 cases of regression of sebaceous carcinoma of the eyelid after a small incisional biopsy.

Methods

Clinical, imaging, and histopathological findings are presented, with a literature review on regressing ocular tumors.

Results

Our first patient was a 79-year-old man who presented with a 10-month history of progressive left upper eyelid ptosis caused by an eyelid tumor with orbital involvement and confirmed on magnetic resonance imaging. Our second patient was a 70-year-old woman who presented with ptosis with a left upper eyelid mass. Both patients underwent a small incisional biopsy of their lesion. The histopathological diagnoses in both cases were consistent with sebaceous carcinoma. Both patients refused exenteration. Follow-up clinical examination and imaging disclosed total regression of the ptosis and of the neoplasm with no sign of recurrence in both patients over a 4-year period for Case 1 and a 7-year period for Case 2.

Conclusion

Regression following incisional biopsy of basal cell, squamous cell, and Merkel cell carcinoma, including of the eyelid, is well documented. To the best of our knowledge, our 2 cases of sebaceous carcinoma are the first to be reported with total involution clinically and on imaging of the tumor following partial incisional biopsy.

Expression of hormone receptors, adipophilin, and GCDFP-15 in mucinous carcinoma of the skin

BACKGROUND

Primary cutaneous mucinous carcinoma (PCMC) is a rare epithelial tumor with unclear histogenesis.

METHODS

We evaluated the immunohistochemical expression of the estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR) in six cases of PCMC. The immunoreactivity of adipophilin and gross cystic disease fluid protein (GCDFP)-15 was investigated to determine the origin of the tumor.

RESULTS

The study included five males and one female aged 50 to 69 years who presented with a cutaneous mass in the face. Immunoreactivity for ER, PR, and AR was observed in all cases, and all cases were negative for adipophilin but positive for GCDFP-15.

CONCLUSIONS

This report is the first to show AR expression in PCMC. All of followed cases manifested indolent clinical course, and the prognostic significance of hormone receptors in PCMC remains unclear. The negative immunoreactivity of PCMC for adipophilin and positivity for GCDFP-15 suggests a more likely relationship to apocrine than to sebaceous glands.

Hierarchical Cluster Analysis of Cytokeratins and Stem Cell Expression Profiles of Canine Cutaneous Epithelial Tumors

The diagnosis of cutaneous epithelial tumors (CETs) in dogs is based on predominant histological differentiation patterns. However, the expression of a broad panel of antigens has not been comprehensively examined with immunohistochemistry. The present study aims to establish a comprehensive expression profile and identify useful diagnostic markers for each CET type. Cytokeratin (CK), stem cell, and other associated markers were immunohistochemically examined in 110 canine CETs. Among these, CK16 was useful for differentiating between basal and squamous cell carcinomas. Acantholytic squamous cell carcinomas were positive for CK8, CK18, and CK19, suggesting their close association with the apocrine duct. Unlike their benign counterparts, sebaceous carcinomas coexpressed CK5/6 and adipophilin. Smooth muscle actin (SMA) and p63 immunostaining were useful for accurately distinguishing between glandular and ductal differentiation in apocrine tumors. A case of apocrine carcinoma and malignant myoepithelioma was identified using anti-SMA antibodies. Stem cell expression profiles (CK8, CK15, CK19, and CD34) of hair follicle tumors were discrete and indicative of their anatomic origins. The effectiveness of immunohistochemistry for tumor diagnosis was further confirmed by hierarchical cluster analysis, through which selected markers were able to sort CETs into specific groups: CK5/6, CK8, CK14, CK16, CK18, CK19, p63, adipophilin, and SMA sorted tumors of epidermal, apocrine, or sebaceous origin; while CK8, CK14, CK15, CK16, CK19, CD34, and p63 sorted hair follicle tumors in agreement with their histological differentiation. In conclusion, the present study provides comprehensive immunohistochemical information, which could complement histomorphological features for the future classification of canine CETs.

Updates on the clinical diagnosis and management of ocular sebaceous carcinoma: a brief review of the literature

Ocular sebaceous carcinoma (SC) is an exceedingly rare but aggressive malignancy that can impair patients’ visual acuity or even cause tumor-specific mortality. This tumor usually mimics chronic benign eyelid lesions, thus leading to delayed diagnosis, thereby causing high recurrence and metastasis. Ophthalmologists should be more aware of SC in order to offer correct diagnosis and treatment at the onset of symptoms. Prompt surgical excision with frozen section margin control is the mainstay of SC management after patient evaluation and accurate biopsy. Mohs micrographic surgery has been associated with better tumor control outcomes than wide local excision. Radiation therapy should be considered as adjuvant treatment for locally advanced (stage T3a or higher) or high-risk (pagetoid spread) SC, nodal metastasis, or palliative care. Cryotherapy and topical chemotherapy are used for pagetoid spread. Targeted therapy has an emerging role in more complicated cases. For lymph node and distant metastasis, combination treatments should be provided, including lymph node and neck dissection, radiation therapy, systemic chemotherapy, and even orbital exenteration. The rarity of ocular SC precludes a comprehensive perspective on standard treatment. This paper offers a brief review of recent advances in the clinical diagnosis and management of ocular SC based on current scientific literature.

Sebaceous cell differentiation in a canine oral papilloma

Papillomas caused by viral infection are well-known tumors in animals. Microscopic features typically include neoplastic epithelium with hyperkeratosis and koilocytes. An 8-y-old castrated male Shih Tzu dog was presented with a small exophytic mass on the external upper lip. The mass was diagnosed as a viral papilloma based on microscopic and immunohistochemical examination. Sebaceous cell differentiation was found in the neoplastic epithelium of the tumor, which is a rare finding in humans or animals.

Extraocular sebaceous carcinoma accompanied by invasive squamous cell carcinoma: The first case report and consideration of histogenesis

A 61-year-old man presented with a dome-shaped nodule, 1.2 cm in size, with a central crater covered by keratinous material near the left lateral malleolus. Histological findings demonstrated a basophilic circular cone in the center, surrounded and sharply demarcated by a broad eosinophilic area. The central conical mass was composed mainly of atypical basaloid cells intermingled with scattered atypical sebaceous cells with scalloped nuclei and microvesicular cytoplasms, suggesting sebaceous carcinoma. The peripheral area consisted of atypical keratinizing squamoid cells without sebaceous cells, suggesting invasive squamous cell carcinoma. Atypical sebaceous cells were positive for adipophilin. Atypical basaloid cells were positive for 34βE12 and CAM5.2. Peripheral squamoid cells were positive for 34βB4 and 34βE12 throughout, and were positive for LHP1 in the superficial layer. We herein describe the first case of extraocular sebaceous carcinoma accompanied by invasive squamous cell carcinoma, which might have arisen from biphasic differentiation of cancer stem cells.

Evaluation and comparison of staining patterns of factor XIIIa (AC-1A1), adipophilin and GATA3 in sebaceous neoplasia

BACKGROUND

Reliable nuclear immunohistochemical stains for sebaceous neoplasms have not been readily available. Positive nuclear staining has been reported for GATA3 and factor XIIIa (AC-1A1). We sought to determine the diagnostic utility of these nuclear stains by comparing their staining pattern to adipophilin, a consistently positive cytoplasmic stain.

METHODS

Cases with the diagnosis of sebaceous hyperplasia, sebaceous adenoma, sebaceous epithelioma/sebaceoma, sebaceous carcinoma, and nonsebaceous neoplasms (basal cell carcinoma and squamous cell carcinoma) were examined. Intensity and extent of staining of the basal cells and mature sebocytes were evaluated for each stain.

RESULTS

Factor XIIIa (AC-1A1) was 87.3% sensitive and 95.1% specific for all sebaceous neoplasms sand showed high inter-observer reliability. Adipophilin was 83.2% sensitive and 87.8% specific. GATA3 was the least sensitive (80.9%) and specific (75.6%) marker. When factor XIIIa was compared against composite staining of all three markers its staining was still uniquely significant (P = .0210).

CONCLUSION

Factor XIIIa (AC-1A1) is a sensitive and specific nuclear marker for sebaceous differentiation. Its diagnostic utility exceeds that of adipophilin. Factor XIIIa should be included in the expanding group of immunohistochemical and special stains which can be utilized to aid in the diagnosis of sebaceous neoplasms.

Updates in ophthalmic pathology

Ophthalmic pathology has a long history and rich heritage in the field of ophthalmology. This review article highlights updates in ophthalmic pathology that have developed significantly through the years because of the efforts of committed individuals and the confluence of technology such as molecular biology and digital pathology. This is an exciting period in the history of ocular pathology, with cutting-edge techniques paving the way for new developments in diagnostics, therapeutics, and research. Collaborations between ocular oncologists and pathologists allow for improved and comprehensive patient care. Ophthalmic pathology continues to be a relevant specialty that is important in the understanding and clinical management of ocular disease, education of eye care providers, and overall advancement of the field.