A histochemical and immunohistochemical study of extra-ocular sebaceous carcinoma

External auditory canal sebaceous carcinoma

The incidence of sebaceous carcinoma (SC) in the outer one-third of the external auditory canal is considered extremely rare, and only eight case reports have been published. We present a case of a male patient in his late 70s known case of hypertension on indapamide. His medical history included a postspinal tumour that had been treated with surgery and radiation more than 40 years ago and current complaints of right ear pain and purulent discharge. A right ear soft granular tissue mass was found. Complete debulking of the right ear mass was done in conjunction with middle ear exploration, moderately differentiated SC diagnosis was made based on the histopathological analysis. The patient was free of recurrence but then died of an unrelated pulmonary infection. SC should be suspected in elderly patients who present with long-term complaints of a mass with or without otalgia, and these patients should be examined for the presence of such tumours especially if they report a history of radiation. Additionally, more research is warranted to investigate the association of diuretics with SC.

Sebaceous carcinoma of the lip: a case report and review of the literature

BACKGROUND

Sebaceous carcinoma is a very rare, aggressive, malignant tumor arising in the adnexal epithelium of the sebaceous gland. Sebaceous carcinoma in the oral cavity is extremely rare, with only 14 cases reported in literature. We reported the fourth case of sebaceous carcinoma involving the lip CASE PRESENTATION: A 71-year-old Caucasian male smoker presented an ulcerated lesion in the lateral region of the lower lip. The patient stated that the lesion had been present for 1 year. The past medical history was unremarkable. Extraoral examination revealed a markedly ulcerated, exophytic, irregularly shaped, indurated mass of the lower right labial region, measuring 1.8 cm in size. The nodular lesion, located at the point of transition between mucosa and skin, showed a central ulceration. No other intraoral lesions were identified. The clinical differential diagnosis included squamous cell carcinoma, basal cell carcinoma with sebaceous differentiation, and salivary gland neoplasms. Operation was performed under local anesthesia. On histopathological examination, the tumor was composed by nodules or sheet of cells separated by a fibrovascular stroma. The neoplastic tissue was deeply infiltrating, involving the submucosa and even the underlying muscle. Neoplastic cells showed a range of sebaceous differentiation with finely vacuolated rather than clear cytoplasm. Neoplastic cells were positive for S-100 protein and epithelial membrane antigen, but negative for carcinoembryonic antigen. Based on these findings, a diagnosis of sebaceous carcinoma of the lower lip was rendered.

CONCLUSION

The histogenesis, differential diagnosis, and clinicopathological conditions of this disease according to literature are reviewed. Sebaceous carcinoma should be distinguished from other tumors full of vacuolated clear cells. A periodic acid-Schiff stain and immunohistochemical stain for Ki-67, P53, cytokeratin, S-100, epithelial membrane antigen, and androgen receptor can be useful for the diagnosis.

Sebaceous carcinoma: evidence-based clinical practice guidelines

Sebaceous carcinoma usually occurs in adults older than 60 years, on the eyelid, head and neck, and trunk. In this Review, we present clinical care recommendations for sebaceous carcinoma, which were developed as a result of an expert panel evaluation of the findings of a systematic review. Key conclusions were drawn and recommendations made for diagnosis, first-line treatment, radiotherapy, and post-treatment care. For diagnosis, we concluded that deep biopsy is often required; furthermore, differential diagnoses that mimic the condition can be excluded with special histological stains. For treatment, the recommended first-line therapy is surgical removal, followed by margin assessment of the peripheral and deep tissue edges; conjunctival mapping biopsies can facilitate surgical planning. Radiotherapy can be considered for cases with nerve or lymph node involvement, and as the primary treatment in patients who are ineligible for surgery. Post-treatment clinical examination should occur every 6 months for at least 3 years. No specific systemic therapies for advanced disease can be recommended, but targeted therapies and immunotherapies are being developed.

Topics in histopathology of sweat gland and sebaceous neoplasms

This article reviews several topics regarding sweat gland and sebaceous neoplasms. First, the clinicopathological characteristics of poroid neoplasms are summarized. It was recently reported that one-fourth of poroid neoplasms are composite tumors and one-fourth are apocrine type lesions. Recent progress in the immunohistochemical diagnosis of sweat gland neoplasms is also reviewed. CD117 can help to distinguish sweat gland or sebaceous tumors from other non-Merkel cell epithelial tumors of the skin. For immunohistochemical differential diagnosis between sweat gland carcinoma (SGC) other than primary cutanesous apocrine carcinoma and skin metastasis of breast carcinoma (SMBC), a panel of antibodies may be useful, including p63 (SGC⁺ , SMBC^- ), CK5/6 (SGC⁺ , SMBC^- ), podoplanin (SGC⁺ , SMBC^- ) and mammaglobin (SGC^- , SMBC⁺ ). Comparison of antibodies used for immunohistochemical diagnosis of sebaceous carcinoma (SC) suggests that adipophilin has the highest sensitivity and specificity. Some authors have found that immunostaining for survivin, androgen receptor and ZEB2/SIP1 has prognostic value for ocular SC, but not extraocular SC. In situ SC is rare, especially extraocular SC, but there have been several recent reports that actinic keratosis and Bowen's disease are the source of invasive SC. Finally, based on recent reports, classification of sebaceous neoplasms into three categories is proposed, which are sebaceoma (a benign neoplasm with well-defined architecture and no atypia), borderline sebaceous neoplasm (low-grade SC; an intermediate tumor with well-defined architecture and nuclear atypia) and SC (a malignant tumor with invasive growth and evident nuclear atypia).

Sebaceous carcinoma in patients receiving long-term immunosuppresive treatment: case report and literature review

BACKGROUND

Sebaceous carcinoma (SC) is a very rare and aggressive malignant skin cancer that appears to occur with a greater frequency in the clinical setting of chronic immunosuppression; however, it is not reported in the literature as frequently as is squamous cell carcinoma (SCC). We report 2 cases of SC in organ transplant patients from clinical and histopathological points of view.

METHODS

A 48-year-old patient after 3 renal transplantations (1986, 1986, and 1998) was presented to the Dermatology Department in 1999 because of a papillomatous lesion along her right upper eyelid. The lesion was excised. Histopathologically, it was diagnosed as a SC. There was no lymphovascular invasion and no metastasis; therefore no other treatment was included. No symptoms of recurrent disease were present 14 years since diagnosis. An 87-year-old patient after a renal transplantation in 1989 was referred to dermatologist in 1993 because of the lesion on his right temple. The lesion was excised; histopathologically, it was diagnosed as SC. Because of metastatic disease, he had a course of radiotherapy to the right side of the neck. The immunosuppressive drugs azathioprine and cyclosporine A were reduced. The patient died of metastatic disease 1 year later (3 years since diagnosis). Both patients had very high cumulative UV exposition during their lifetimes, and many skin cancers were diagnosed, especially SCC.

RESULTS

It is necessary to realize that this cancer occurs more frequently in organ transplant patients, and its correct diagnosis is an essential issue because it has significantly more aggressive behavior than does SCC. In the 2 presented patients, we observed very rapid progression of disease. Despite aggressive treatment and reduction of immunosuppressive drugs, the second patient died 3 years after diagnosis.

CONCLUSIONS

Regular dermatological follow-up is required in the population of organ transplant patients to identify all skin tumors in the early stage.

Inguinal ulcerated sebaceous carcinoma: an unusual presentation

Sebaceous carcinoma is a rare and aggressive skin tumor. It can be located in any area of the body, the most commonly involved area being the periorbital region. It does not entail a typical clinical presentation, which explains the often late diagnosis. The aim of this report is to outline the rarity of the disease and its atypical clinical description, since to this day, inguinal ulcers with clinical manifestation have not been reported. We present and discuss a case of sebaceous carcinoma with an unusual clinical presentation, in an elderly male patient. The precise approach to genital ulcers, as shown in this case, is a diagnostic challenge that requires a great deal of effort on the part of the clinician.

Characteristics of sebaceous carcinoma and early outcomes of treatment using Mohs micrographic surgery versus wide local excision: an update of the Mayo Clinic experience over the past 2 decades

BACKGROUND

Sebaceous carcinoma (SC) is a rare cutaneous neoplasm.

OBJECTIVE

To characterize SC and treatment approaches and outcomes.

METHODS AND MATERIALS

We retrospectively reviewed records of patients with SC from 1992 through 2012. Recurrence-free survival was estimated and compared between groups.

RESULTS

We identified 52 patients with SC (39, 75.0% male). Mean age ± standard deviation at diagnosis was 72.7 ± 10.8. Forty-nine patients (94.2%) were white. Twenty-one (of 29 with known status) had a diagnosis of Muir-Torre syndrome. Six had multiple primary SCs (total of 73 SCs in 52 patients). The most common locations for SC were the back (20.5%), cheek (13.7%), nose (11.0%), and eye (9.6%). Treatment was recorded for 70 SCs; 35 (50.0%) were treated using Mohs micrographic surgery (MMS) and 26 (37.1%) using wide local excision (WLE). Of the 45 patients (66 SCs) with clinical follow-up, three (6.7% of patients; 4.8% of SCs) had documented recurrence.

CONCLUSION

MMS and WLE are effective treatments for SC. Further research is warranted to determine whether one treatment is more efficacious than the other.

Multifocal metastasizing extra-ocular facial sebaceous carcinoma as diagnostic challenge: case report and systematic review

PURPOSE

Sebaceous carcinoma (SC) is a rare adnexal tumor. Extra-ocular, facial SC is very uncommon and local metastases are an extreme rare finding. A respective case is presented and discussed together with the current literature.

CASE AND REVIEW

A tumor of the left ear of an 87-old male was primary excised together with multiple suspicious lesions of the head and neck. Most specimens were histopathologically rated as squamous cell carcinomas (SCC). Despite the in-sano resection, additional new suspicious retro-auricular and temporal lesions were detected. Successive resections were diagnosed as basal cell carcinomas (BCC) and, because of a non-in-sano resection in a third approach, as SC. After reappraisal and immunhistochemical staining [epithelial membrane antigen (EMA), CK 5-6 and CD 15], most of the former specimens turned out to be SC as well. A literature search showed 3 reported cases of extra-ocular head and neck SC with cutaneous local metastases. In another review, in a total of 168 cases, SC was diagnosed after wrong initial histological diagnosis (SCC n = 56, BCC n = 44; other entity or precursors of carcinomas n = 68).

CONCLUSION

Due to inconsistent histologic patterns, histopathological misdiagnosis of the uncommon facial SC and its metastases may complicate further therapy, prolong treatment and may lead to a worse prognosis of this neoplasm. A close interdisciplinary collaboration of clinician, surgeon and pathologist is of most relevance for the right diagnosis.

Role of immunohistochemistry in diagnosing tumors of cutaneous appendages

In recent years, there has been significant progress in immunohistochemistry as an ancillary tool in diagnostic dermatopathology. In most instances, the histologic diagnosis can be rendered with the routine histologic sections; however, immunohistochemistry can help to narrow the differential in diagnosing neoplasms of cutaneous appendages in some settings including adnexal versus epidermal origin, benign versus malignant adnexal neoplasms, and primary adnexal carcinoma versus cutaneous metastases as outlined in this review.

Sebaceous carcinoma: an immunohistochemical reappraisal

The rates of distant metastases and tumor death in sebaceous carcinoma (SC) have been reported to be higher than those of other cutaneous carcinomas, such as squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), regardless of whether they occur in ocular or extraocular regions. Therefore, strict differentiation of SC from SCC and BCC is required. In this article, we report immunohistochemical findings of SC and compare these data to those of SCC, BCC, and sebaceoma. An immunohistochemical study was performed using 7 antibodies [anti-carcinoembryonic antigen (CEA), anti-epithelial membrane antigen (EMA), anti-CA15-3, anti-CA19-9, anti-androgen receptor (AR), anti-epithelial antigen (Ber-EP4), and anti-adipophilin (ADP)] on 35 cases of SC (16 cases in ocular and 19 cases in extraocular regions) and 10 cases of each SCC (5 cases in ocular and 5 cases in extraocular regions), BCC (5 cases in ocular and 5 cases in extraocular regions), and sebaceoma (no cases arose on the eyelids). In summary, the typical immunophenotypes of SC were EMA+, CA15-3+, AR+, Ber-EP4-, and ADP+; those of sebaceoma were CEA-, EMA+, Ber-EP4-, and ADP+; those of SCC were CEA-, EMA+, CA19-9-, AR-, Ber-EP4-, and ADP-; and those of BCC were CEA-, EMA-, CA15-3-, Ber-EP4+, and ADP-. Other antibody tests for each neoplasm were positive in about half of the cases. The detection of AR and ADP was useful for differentiating SC from SCC, whereas the determination of EMA, CA15-3, Ber-EP4, and ADP was valuable in differentiating SC from BCC.

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

Adipophilin is a monoclonal antibody against a protein on the surface of intracellular lipid droplets, and it was recently shown to be expressed in sebocytes and sebaceous lesions. This study examines adipophilin expression in various sebaceous lesions and other cutaneous tumors with a clear cell histology that may mimic sebaceous differentiation. A total of 117 cutaneous clear cell lesions including 16 sebaceous adenomas, 25 sebaceous carcinomas, 8 basal cell carcinomas, 12 squamous cell carcinomas, 6 xanthomas, 10 xanthelasmas, 10 xanthogranulomas, 4 balloon cell nevi, 5 trichilemmomas, 8 clear cell hidradenomas, and 13 metastatic renal cell carcinomas were examined using immunohistochemistry for the expression of adipophilin. Of these 117 lesions, 42 (36%) were from the periocular region. Adipophilin was expressed in 16 of 16 (100%) sebaceous adenomas, 23 of 25 (92%) sebaceous carcinomas, 10 of 10 (100%) xanthelasmas, 9 of 10 (90%) xanthogranulomas, 6 of 6 (100%) xanthomas, and 9 of 13 (62.5%) metastatic renal cell carcinomas. The characteristic staining pattern differed between sebaceous and non-sebaceous tumors with the former showing a membranous vesicular pattern and the latter being more granular. Adipophilin expression was not seen in any of the other lesions with clear cell histology, basal cell carcinomas, or squamous cell carcinomas, including cases that had focal clear cell differentiation. Adipophilin can be valuable in an immunohistochemical panel when evaluating cutaneous lesions with clear cell histology as it identifies intracytoplasmic lipid vesicles in sebaceous and xanthomatous lesions. In periocular lesions, it is effective in helping to exclude basal cell carcinoma and squamous cell carcinoma when sebaceous carcinoma is under consideration. Adipophilin expression is not as useful for the differential diagnosis that includes metastatic renal cell carcinoma, a rare but important, diagnostic differential. The pattern of adipophilin reactivity is important to observe as membranous vesicular staining is suggestive of intracellular lipids whereas granular cytoplasmic reactivity is not.

Immunohistochemical expression of D2-40 in benign and malignant sebaceous tumors and comparison to basal and squamous cell carcinomas

The diagnosis of sebaceous carcinoma presents an important challenge to both clinicians and pathologists, as many cases are initially misdiagnosed both clinically and histopathologically, potentially leading to adverse medical and legal outcomes. The distinction of sebaceous carcinoma from benign sebaceous proliferations and other tumors is therefore of utmost importance, and immunohistochemistry may be useful in this differential. We studied the expression of D2-40 (podoplanin) by immunohistochemistry to determine if it can aid in this differential diagnosis and to evaluate the possibility of lymphangiogenesis in sebaceous carcinoma. A total of 36 cases of sebaceous lesions, including 16 sebaceous carcinomas, 7 sebaceous adenomas, 6 sebaceomas, and 7 cases of normal glands and sebaceous hyperplasia, and 17 cases of basal cell carcinoma and 10 cases of squamous cell carcinoma, were also examined. We found no significant increase in tumor lymphangiogenesis by semiquantitative scoring of lymphovascular density per square millimeter of tumoral/peritumoral stroma in sebaceous carcinoma versus benign sebaceous proliferations. However, D2-40 staining showed a different pattern in the benign tumors, which were positive only in the basaloid cells (most pronounced in sebaceoma), versus sebaceous carcinoma, which was either negative or focally positive in a haphazard pattern in most cases, although some cases of basaloid sebaceous carcinomas showed strong positivity. We also found D2-40 to be only weakly and focally positive in basal cell carcinoma and weakly to moderately positive in squamous cell carcinoma, which showed increased staining with decreased differentiation. Therefore, overall, D2-40 is, of limited diagnostic utility in sebaceous lesions but may be useful in distinguishing sebaceoma and basaloid sebaceous carcinoma from basal cell carcinoma.

Diagnosis and management of sebaceous carcinoma: an Australian experience

BACKGROUND

Cutaneous sebaceous carcinoma (SC) is a rare malignancy derived from adnexal epithelium of sebaceous glands. Periorbital SC is approximately three times more common than extraorbital SC. To date, there are few data from an Australian source to document the prevalence or clinical outcome of this tumour.

METHODS

A retrospective review was undertaken of the cases from the Institute of Clinical Pathology and Medical Research using their histopathology database for patients with a diagnosis of SC. Patients were identified over a period of 34 years from 1971-2005 and their management and follow up are reported.

RESULTS

There were 25 patients in all. Seventeen were men and eight were women. Of the 25 cases, 12 were extraorbital and 13 were periorbital. Three metastases and one tumour showed extensive local invasion. There were nine cases of incomplete excisions and 13 patients were reoperated on for either incomplete excisions, to obtain a wider margin or for local recurrences. Adjuvant radiotherapy was used on five patients, three of whom had lymph node deposits.

CONCLUSION

Sebaceous carcinoma is a rare tumour. Extraorbital SC is an aggressive and invasive malignancy. Excision margins may need to be wider than previously thought. Exposure to ultraviolet radiation (sunlight) may play a role in the aetiology. Wide excision and selective use of radiotherapy remain the treatment of choice.

Adnexal clear cell carcinoma with comedonecrosis: clinicopathologic analysis of 12 cases

CONTEXT

Cutaneous clear cell tumors can pose a diagnostic challenge even to the experienced dermatopathologist; this is partly because of limitations of existing diagnostic categories.

OBJECTIVE

To describe a previously unrecognized, distinctive cutaneous adnexal carcinoma capable of an aggressive clinical course.

DESIGN

Clinicopathologic analysis of a series of 12 cases.

RESULTS

The patients were older individuals (median age, 71 years) with equal gender frequency. The lesions showed wide anatomic distribution with predilection for the head and neck area, especially the scalp. The lesions presented as rapidly growing, erythematous to flesh-colored, solitary papules/nodules that were capable of quickly reaching a size of several centimeters. Histologically, adnexal clear cell carcinoma with comedonecrosis was characterized by dermal proliferation of nests of epithelial cells showing distinctive zonal arrangement. The periphery of the tumor nests was formed by squamoid cells merging with centrally located clear cell areas containing foci of comedonecrosis. The lesions often showed multilobular or trabecular growth pattern and infiltrating border. Nuclear pleomorphism was variable; mitotic count ranged from 2 to 32/mm2 (median, 8/mm2). No ductal, cuticular, or apocrine differentiation was seen. All cases showed expression of epithelial membrane antigen and cytokeratin 17 in clear cells, with focal carcinoembryonic antigen expression in some cases. Follow-up (average, 37 months) revealed local recurrence (4 cases) and regional and distant metastases (2 cases).

CONCLUSIONS

Adnexal clear cell carcinoma with comedonecrosis appears to be a distinctive adnexal neoplasm that has to be distinguished from more indolent squamous cell and tricholemmal carcinomas.

Sebaceous neoplasia and Torre-Muir syndrome

Sebaceous tumours include hyperplasia, adenoma, sebaceoma and carcinoma. Importantly, the latter three are potential markers of Torre-Muir syndrome; the hereditary association of sebaceous neoplasia and internal malignancy, most commonly colorectal carcinoma. The diagnostic features, differential diagnosis, molecular diagnostics and recent advances in pathogenesis of this rare group of tumours are discussed along with Torre-Muir syndrome and recommendations for screening for this important association.

Characteristic Ber-EP4 and EMA expression in sebaceoma is immunohistochemically distinct from basal cell carcinoma

AIMS

There is considerable overlap between the histological features of sebaceoma and basal cell carcinoma (BCC). The distinction between these two tumours is important due to the often more locally aggressive nature of BCC and the association of sebaceoma with the Muir-Torre syndrome. The aim of this study was to describe the immunohistochemical reactivity of the cells in sebaceoma to Ber-EP4 and epithelial membrane antigen (EMA) and investigate the utility of this panel to differentiate sebaceoma from basal cell carcinoma.

METHODS AND RESULTS

Immunohistochemistry of 25 sebaceomas for Ber-EP4 and EMA revealed unequivocal negative expression of Ber-EP4 in 24 of 25 sebaceomas. A single case exhibited focal weak Ber-EP4 staining, predominantly in mature sebocytes and in < 10% of the tumour cells. EMA was not expressed in the germinative cells of sebaceoma, but was expressed strongly in approximately 50% of mature sebocytes in all cases and highlighted the cytoplasmic vacuoles. We reviewed the immunoreactivity of 51 cases of nodular BCCs and found moderate or strong BerEP4 expression in all cases with never less than 20% of the tumour staining. Expression of EMA was uncommon in BCC (moderate or strong in 8%) and was confined to keratotic or squamoid areas.

CONCLUSION

The use of Ber-EP4 in combination with EMA, both widely used immunomarkers in histopathology, is a helpful aid in distinguishing sebaceoma from nodular BCC.

Renal cell carcinoma marker (RCC-Ma) is specific for cutaneous metastasis of renal cell carcinoma

BACKGROUND

Renal cell carcinoma marker (RCC-Ma) is a monoclonal antibody against a normal renal proximal tubule antigen. RCC-Ma expression is relatively specific for primary clear cell renal cell carcinoma. Its expression in cutaneous metastasis of renal cell carcinoma (MRCC) and other cutaneous clear cell lesions has not been studied.

METHODS

One hundred and thirty-seven cutaneous clear cell lesions including eight xanthomas, 32 xanthelasmas, 25 xanthogranulomas, seven balloon cell nevi, six clear cell hidradenomas, 29 sebaceous adenomas, six sebaceous epitheliomas, eight sebaceous carcinomas, and 16 MRCC were examined using immunohistochemistry for the expression of RCC-Ma.

RESULTS

RCC-Ma was expressed in 10 of 16 (62.5%) MRCC, all with greater than 20% of cell labeling. Of these, 4 of 10 (40%) labeled with a membranous pattern and 6 of 10 (60%) labeled with both a membranous and a cytoplasmic pattern. RCC expression was not seen in any of the other clear cell lesions (p < 0.001). Furthermore, lack of expression in each of the other diagnostic groups was significant when each group was compared with the MRCCs (p < 0.01 at least for each group).

CONCLUSIONS

Our study demonstrates that RCC may be a valuable component of a panel of immunohistochemical markers when evaluating cutaneous clear cell lesions.

Intraoral sebaceous carcinoma

Intraoral sebaceous carcinoma (SC) is a rare tumour in the oral cavity thought to arise from malignant transformation of oral sebaceous glands. To our knowledge, only six cases of intraoral SC have been reported in the English language literature. The purpose of the present article is to report an additional case and review the literature.

Sebaceous carcinoma of the breast: case report and review of the literature

Sebaceous differentiation has been described in only limited examples of benign and malignant epithelial lesions of the breast. We report a rare case of mammary sebaceous carcinoma to further delineate its morphologic features. Microscopically, the tumor, arising in the right mammary gland of a 63-year-old woman, was composed of well-defined solid sheets or lobules of atypical epithelial cells including many large pale or clear cells with often scalloped nuclei and coarsely vacuolated cytoplasm, in which abundant lipid droplets were identified with oil-red-O staining. Immunohistochemical expressions of cytokeratin, epithelial membrane antigen, and receptors of estrogen and progesterone were detected, whereas GCDFP-15, S-100 protein, vimentin, alpha-smooth muscle actin, p63, androgen receptor, and the HER2/neu protein were not expressed. Besides, a subset of the tumor cells co-expressed synaptophysin, neurofilament, and PGP9.5, suggesting neuroendocrine differentiation that is a hitherto undescribed phenomenon in the mammary tumors with sebaceous features. This case would expand the morphologic diversity of carcinoma of the breast.

Immunohistochemical staining for adipophilin, perilipin and TIP47

BACKGROUND

The presence of lipid in the cell cytoplasm is useful for supporting the diagnosis of sebaceous gland carcinoma (SGC). Currently this requires histochemical stains that are carried out on frozen sections of unprocessed tissue. Recently, several anti-adipocytic antibodies that recognise proteins associated with lipid vesicles have been described. These antibodies can be applied to paraffin-wax sections.

AIM

To assess the ability of anti-adipocytic antibodies to identify intracytoplasmic lipid in SGC.

METHODS

Immunohistochemistry with a monoclonal antibody to adipophilin and polyclonal antibodies to perilipin and TIP47/PP17 was carried out on archival, formalin-fixed, paraffin-wax-embedded sections of 26 samples of SGC. The immunostaining was compared with 22 other eyelid tumours (11 basal cell carcinomas (BCC), 10 squamous cell carcinomas (SCC) and 1 Merkel cell tumour).

RESULTS

Immunohistochemical staining was positive in 23, 10 and 2 cases of 26 SGC with adipophilin, perilipin and TIP47, respectively. The positive staining identified cytoplasmic lipid vesicles. Anti-adipophilin was positive in five other eyelid tumours (4 BCC and 1 SCC) staining small cytoplasmic granules that can be easily distinguished from the staining in SGC.

CONCLUSIONS

Immunohistochemical staining for adipophilin and perilipin is a useful ancillary technique for the demonstration of lipid in SGC that may be applied to paraffin-wax sections.

Malignant adnexal neoplasms

Malignant cutaneous adnexal neoplasms are one of the most challenging areas of dermatopathology. Tumors of the pilosebaceous apparatus can occur as single-lineage neoplasms or may manifest as complex proliferations with multilineal differentiation patterns including not only the germinative component of the hair bulb, the inner or outer root sheath epithelium and the sebaceous gland and duct, but also the sweat duct components that relate to the apocrine secretory apparatus which empties into the follicle near the follicular bulge. Eccrine and apocrine neoplasms present a bewildering array of morphologies, which often defy precise classification. The purpose of this review is to discuss in detail the malignant neoplasms of the cutaneous adnexae and their benign and prognostically indeterminate mimics.

Immunohistochemical differentiation of extra-ocular sebaceous carcinoma from other skin cancers

We performed an immunohistochemical study using routinely processed formalin-fixed and paraffin-embedded tissue specimens from 26 cases of extra-ocular sebaceous carcinoma (EOSC) and eight easily available antibodies. They were polyclonal anti-carcinoembryonic antigen (CEA) antibody, monoclonal anti-CEA antibody, anti-breast carcinoma associated antigen-225 antibody (CU18), anti-CA15.3 antibody (CA15.3), anti-CD15 antibody (CD15), anti-breast carcinoma associated antigen antibody (B6.2), anti-gross cystic disease fluid antigen-15 antibody (GCDFP15) and anti-Thomsen-Friedenreich antigen antibody (TFA). Squamous cell carcinoma, porocarcinoma, syringomatous carcinoma, malignant clear cell hidradenoma, apocrine adenocarcinoma, and extramammary Paget's disease with underlying adenocarcinoma were used as controls. EOSC was positive for CU18 and CA15.3 in most cases, and for CD15 in a few cases. Squamous cell carcinoma of the skin was positive for CA15.3 in only one case. Porocarcinoma, syringomatous carcinoma and malignant clear cell hidradenoma were positive for CEA, CU18, CA15.3, and B6.2 in most cases. Apocrine adenocarcinoma and extramammary Paget's disease with underlying adenocarcinoma were positive for CEA, CU18, CD15, GCDFP15, CA15.3, and B6.2 in most cases. TFA was positive not only in EOSC but also in other skin cancers. Immunohistochemical examinations using these seven of eight antibodies except for TFA and routinely processed formalin-fixed and paraffin-embedded tissue specimens are beneficial in differentiating EOSC from other skin cancers.

Sebaceous carcinoma of the oral mucosa: case report and review of the literature

Fordyce granules are found in the oral mucosa of up to 80% of adults. However, primary malignant sebaceous tumors of the oral mucosa are exceedingly rare. To our knowledge, only 5 examples of intraoral sebaceous carcinoma have been reported in the literature. This report describes a primary sebaceous carcinoma of the labial mucosa that arose in an area containing numerous Fordyce granules. A brief review of the clinical and histopathologic features of sebaceous carcinoma is also presented.

Non-melanocytic lesions mimicking melanocytic lesions

Distinction between benign and malignant melanocytic lesions commonly represents a big challenge for the pathologist. Equally difficult is separating tumours with melanocytic lineage from those displaying other lines of differentiation. This is because benign and malignant melanocytic lesions are able to display a wide range of histological appearances that frequently closely mimic reactive and neoplastic lesions (benign and malignant). This applies to processes with almost any line of differentiation. Difficulties in differential diagnosis are mainly found in melanocytic lesions restricted to the dermis or those in which the junctional component is minimal. Although purely junctional melanocytic lesions less commonly pose a problem in differential diagnosis, they may be very problematic, especially in small biopsies. Immunohistochemistry is usually a very important aid in the differential diagnosis of mimics of melanocytic lesions but pitfalls often occur. This is particularly true when small samples are analysed and when close clinicopathological correlation is lacking. This review discusses the histological differential diagnosis of mimics of melanocytic lesions. These mimics are separated into those primarily presenting in the epidermis and those presenting in the dermis.

Biological Behavior of the Sebaceous Carcinoma of the Head

BACKGROUND

The reports in the literature indicate that extraocular sebaceous carcinoma (SC), in contrast to orbital SC, is less aggressive and rarely metastasizes.

METHODS

Of 2422 epithelioma cases observed over 10 years, 8 (0.33%) resulted as histologically proven SCs, all of which were located in the head.

RESULTS

The clinical behavior of these tumors was observed by following patients for an average period of 50 months. Three of the tumors originated from the orbital region and five from other areas of the head (extraocular). In one case, the SC was associated with renal carcinoma (Muir-Torre syndrome). None of the orbital tumors metastasized, whereas two of the five cases of extraocular carcinoma metastasized to the locoregional lymph nodes.

CONCLUSION

It should be stressed that in this case study aggressive biologic behavior was observed in carcinoma arising from extraorbital areas.

Clear cell eccrine porocarcinoma with extensive cutaneous metastasis and peripheral lymphocyte dysfunction

An 81-year-old woman came to our clinic (Department of Dermatology, Kaohsiung Medical University, Kaohsiung, Taiwan) with multiple erythematous, indurated papules over the left side of her face. Two years earlier, the patient had a skin biopsy done at a similar anatomical area with the histopathological diagnosis of Bowen's disease. After reviewing surgical specimens and confirming no systemic involvement, clear cell eccrine porocarcinoma with extensive cutaneous metastasis has been diagnosed. In addition, the peripheral blood lymphocyte function of the patient was evaluated. The expression of interleukin-2 receptors on lymphocytes after stimulation is abnormal compared with the age-matched normal control and a patient with cutaneous squamous cell carcinoma. This clinical manifestation of eccrine porocarcinoma is exceptional, and lymphocyte dysfunction in this patient has probably contributed to extensive cutaneous metastasis.

Structure and function of human sweat glands studied with histochemistry and cytochemistry

The basic structure and the physiological function of human sweat glands were reviewed. Histochemical and cytochemical techniques greatly contributed the elucidation of the ionic mechanism of sweat secretion. X-ray microanalysis using freeze-dried cryosections clarified the level of Na, K, and Cl in each secretory cell of the human sweat gland. Enzyme cytochemistry, immunohistochemistry and autoradiography elucidated the localization of Na,K-ATPase. These data supported the idea that human eccrine sweat is produced by the model of N-K-2Cl cotransport. Cationic colloidal gold localizes anionic sites on histological sections. Human eccrine and apocrine sweat glands showed completely different localization and enzyme sensitivity of anionic sites studied with cationic gold. Human sweat glands have many immunohistochemical markers. Some of them are specific to apocrine sweat glands, although many of them stain both eccrine and apocrine sweat glands. Histochemical techniques, especially immunohistochemistry using a confocal laser scanning microscope and in situ hybridization, will further clarify the relationship of the structure and function in human sweat glands.

Intraoral sebaceous carcinoma

Sebaceous carcinoma in the oral cavity is extremely rare, and we have found only four previously reported cases. We describe a fifth case. A wide surgical excision seems to be the correct treatment and estimation of serum carcinoembryonic antigen (CEA) may be a useful tumour marker in the follow-up of intraoral sebaceous carcinomas.

A case of syringocystadenocarcinoma papilliferum in situ occurring partially in syringocystadenoma papilliferum

We report a case of syringocystadenocarcinoma papilliferum in situ associated with syringocystadenoma papilliferum. The patient was a 64-year-old man with a red tumor that arose on top of his head two years before he consulted our department. The histological findings revealed a papillomatous growth on the epidermis forming several invaginations. Numerous papillary projections, lined by a two-layered epithelium with a benign appearance and decapitations on the luminal surface of the cells, extended into the lumens of the invaginations. Some projections showed a disorderly arrangement of multilayered cells with atypical nuclei. No differences between findings in the syringocystadenocarcinoma papilliferum in situ and those in the syringocystadenoma papilliferum were observed histochemically (PAS) or immunohistochemically (cytokeratin, CEA, CA 19-9, S-100, gross cystic disease fluid protein, lysozyme and Leu M1).

Clear cell atypical fibroxanthoma:a clinicopathologic study

INTRODUCTION

The atypical fibroxanthoma (AFX) is considered by most authorities to represent a superficial or minimally invasive variant of malignant fibrous histiocytoma that most often presents as a solitary nodule on the sun-exposed skin of the elderly. Among the rarest variants is the clear cell AFX, a lesion which raises consideration to a differential diagnosis encompassing a variety of neoplastic and non-neoplastic clear cell proliferations.

METHODS

We describe three cases of a distinctive cutaneous neoplasm arising in the sun-exposed skin of elderly patients. In all cases, formalin-fixed, paraffin-embedded tissue was available for analysis. The histology in concert with the immunophenotype was held to be diagnostic of the clear cell variant of AFX.

RESULTS

All tumors comprised sheets of large cells with foamy cytoplasms and hyperchromatic, polyploid nuclei manifesting frequent and atypical mitoses. The critical cells in our cases expressed CD68 but none of CD3, CD20, CD34, S-100 protein, muscle-specific actin, factor XIIIa, Melan-A, carcinoembryonic antigen, or cytokeratin.

CONCLUSION

Although typical examples of AFX provoke diagnostic consideration of spindle cell cancers of the skin (most often spindle cell melanoma, spindle cell squamous cell carcinoma, and leiomyosarcoma), the clear cell variant raises other differential diagnostic considerations instead. These include balloon cell melanoma, sebaceous carcinoma, pleomorphic liposarcoma, chordoma, parachordoma, tricholemmal carcinoma and clear cell squamous cell carcinoma. A diagnosis of AFX is one of exclusion; one must employ immunohistochemical markers to rule out the aforementioned differential diagnostic considerations. By reporting the fifth, sixth and seventh cases of clear cell AFX, we hope to alert dermatopathologists to this distinctive and unusual neoplasm, recognition of which is essential to avoid under- or over-diagnosis and inappropriate therapy.

Sebaceous carcinoma of the lung: histologic and immunohistochemical characterization of an unusual pulmonary neoplasm: report of a case and review of the literature

Sebaceous neoplasms, including carcinomas, are tumors most often seen around the eye and eyelid. Cases of extraorbital sebaceous tumors associated with skin adnexa are less common. The parotid gland may also be a source for sebaceous neoplasms, and cases associated with minor salivary gland tissue have also been reported. Once beyond the oropharynx, individual cases of pharyngeal and laryngeal sebaceous tumors are reported. The case of a patient with primary sebaceous carcinoma of the bronchus is presented. Our case is that of an endobronchial mass that has histopathologic features of a sebaceous carcinoma, with predominance of areas with morphologically classic sebaceous differentiation, confirmed by oil red O stain for lipid, analyzed by immunohistochemistry and evaluated ultrastructurally. This unique tumor extends the spectrum of extraocular, extracutaneous neoplasms with sebaceous differentiation from existing single reports in the hypopharyx and larynx to now include bronchus.

Postauricular sebaceous carcinoma arising in association with nevus sebaceus

BACKGROUND

Sebaceous carcinoma is an uncommon malignant neoplasm usually associated with the ocular adnexa. Despite the widespread anatomic distribution of sebaceous glands, extraocular sebaceous carcinoma occurs with far less frequency.

METHODS

A 27-year-old man was examined with the presenting complaint of a slowly enlarging subcutaneous mass. It was associated with an overlying, irregular, verrucoid epidermal plaque.

RESULTS

Histologic and electron microscopic examination of the mass revealed a malignant sebaceous neoplasm occurring in conjunction with an overlying nevus sebaceus. The dermal neoplasm contained numerous cytoplasmic and stromal hyaline globules.

CONCLUSIONS

We report a case of extraocular sebaceous carcinoma arising in the postauricular region in association with a nevus sebaceus and exhibiting the unusual histologic feature of hyaline globules.

Pagetoid bowen disease: a report of 2 cases that express cytokeratin 7

Bowen disease is a variant of squamous cell carcinoma in situ. In some cases a pagetoid growth pattern can be observed with cytologically atypical clear cells arranged singly and in nests. The differential diagnosis of pagetoid Bowen disease includes primarily Paget disease and malignant melanoma in situ, as well as other less common entities. Two cases of pagetoid Bowen disease are described, one in a 65-year-old man with a thigh lesion and the other in a 25-year-old man with a lesion in the penile/scrotal region. Neither patient had clinical evidence of an internal malignant neoplasm. In both cases, the neoplastic cells were positive for cytokeratin (CK) 7 and CK 19 and were negative for CK 18, CK 20, carcinoembryonic antigen, GCDFP-15, c-erbB2, S100, and HMB-45. In aggregate, these findings support the diagnosis of pagetoid Bowen disease. Previously, others have shown that CK 7 is an almost invariable marker of Paget disease. Thus, we report these two cases to illustrate that CK 7 can be expressed by pagetoid Bowen disease and should not be a cause of confusion in the differential diagnosis.

Sebaceous carcinoma of the breast

We report on a rare distinctive variant of infiltrating ductal carcinoma characterized by sebaceous differentiation of tumor cells. The neoplasm was identified in a lumpectomy specimen from a 45-year-old woman with extensive metastatic disease. In addition to conventional in situ and invasive ductal components, approximately half of the tumor cells exhibited a phenotype resembling tumors of the sebaceous skin appendage with coarsely vacuolated cytoplasm and peripherally displaced nuclei. The sebaceous moiety was also present in the distant metastatic deposits. There was no evidence of mucin production by tumor cells. Ultrastructurally, empty-appearing non-membrane bound vacuoles attested to the sebaceous cells' lipid content. The immunoprofile of the lesion included positivity for cytokeratin and epithelial membrane antigen. Vimentin, S100 protein and carcinoembryonic antigen were not expressed. Most tumor cell nuclei reacted with antibodies to oestrogen and progesterone receptors but failed to show overexpression of the HER2/neu protein. The MIB-1 labeling index averaged 16%. At variance with sebaceous breast carcinomas on record, the present case is notable for its prolonged clinical course.

Dimorphic immunohistochemical staining in ocular sebaceous neoplasms: a useful diagnostic aid

PURPOSE

We studied whether patterns of immunostaining in formalin-fixed, paraffin-embedded tissue could help to distinguish between sebaceous neoplasms of the eyelid and other eyelid neoplasms.

METHODS

We applied antibodies to human milk fat globule-1 (HMFG1), cytokeratins (PKK1 and MNF116), epithelial membrane antigen (EMA) and carcino-embryonic antigen (CEA) to normal eyelid tissue and to a range of sebaceous lesions of the eyelid; these included sebaceous hyperplasia, sebaceous adenoma and sebaceous epithelioma, in addition to well to poorly differentiated sebaceous carcinoma.

RESULTS

The central and peripheral cellular components of normal sebaceous glands and neoplastic sebaceous lesions showed a distinctive dimorphic staining pattern with the antibody panel used. The central foamy 'sebaceous' cells expressed HMFG1 and EMA, but not PKK1 or MNF116, whereas the smaller, peripheral basal and ductal cells expressed PKK1 or MNF116 but not HMFG1 or EMA. CEA expression in sebaceous cells was unhelpful diagnostically.

CONCLUSION

Normal sebaceous glands and all sebaceous neoplasms show a dimorphic cell population that can be identified using a small panel of antibodies on formalin-fixed, paraffin-embedded tissue. This distinctive staining pattern can be assessed retrospectively, even in small biopsies, and largely removes the need for fat stains on frozen sections to differentiate sebaceous lesions from other ocular neoplasms. The results also support the suggestion that ocular sebaceous neoplasms arise from a common stem cell, rather than from either sebaceous or basal/ductal cells.

The Muir-Torre syndrome in a black patient with AIDS: histopathology and molecular genetic studies

In 1981, a black man had adenocarcinoma of the colon. In 1986, he had a sebaceous adenoma and the diagnosis of the Muir-Torre syndrome was established. The patient was found to be HIV sero-positive in 1986, and 8 years later fulfilled the CDC criteria for AIDS. During 1989 to 1993 the CD4 count was > 200 cells/ml and the patient had 2 sebaceous tumors, 1 basal cell carcinoma and 1 keratoacanthoma. In 1994 to 1996, the CD4 count was < 200 cells/ml and the patient developed 18 sebaceous tumors and a poorly differentiated adenocarcinoma of the finger which metastasized to axillary lymph nodes. Microsatellite analysis of tumor DNA from a sebaceous adenoma and adenocarcinoma of the finger revealed widespread microsatellite instability. The interaction of AIDS with the behavior of the tumors in the Muir-Torre syndrome has not previously been reported. Although our patient had an increase in the number of new sebaceous tumors at the same time he experienced deterioration of the immune system, he is doing well 15 years after resection of adenocarcinoma of the colon and 16 months after metastatic poorly differentiated adenocarcinoma of the skin. This follows the previously observed tendency for cancers of the Muir-Torre syndrome, especially those displaying widespread microsatellite instability, to be less lethal than their histologically similar counterparts in people without Muir-Torre syndrome.

Microcystic adnexal carcinoma with extensive sebaceous differentiation

We report two cases of microcystic adnexal carcinoma showing extensive sebaceous differentiation. Multiple cellular nests and strands within a moderately sclerotic stroma involving the full thickness of the dermis were observed. Clusters of basaloid cells with extensive sebaceous differentiation were present. Foci of sebaceous ductal differentiation were observed in the more superficial areas. Neither strikingly atypical cells nor mitotic figures were present. Perineural invasion was present in the deep areas of both tumors. Clinically, the lesions were solitary whitish-pink papules with a central dell on the faces of 2 men (aged 78 and 73 years old). We propose a relationship between these tumors and other cytologically bland but locally aggressive adnexal carcinomas. Sebaceous differentiation itself in a poorly circumscribed neoplasm does not indicate conventional extraocular sebaceous carcinoma. We propose a simple classification of locally aggressive adnexal carcinomas that takes into account the full range of adnexal differentiation that can occur in such lesions.

Gross cystic disease fluid protein-15 reactivity in extramammary Paget's disease with and without associated internal malignancy

Extramammary Paget's disease (EMP) is a rare eczematoid disorder occurring mainly in apocrine-gland-bearing regions. Its histogenesis is controversial. Several investigators have proposed that EMP is a heterologous entity, with some cases representing a de novo adenocarcinoma in situ arising in the epidermis and others being epidermotropic metastases or a direct extension of an associated internal malignancy. We have studied 26 cases of EMP with and without associated internal malignancy for their reactivity with a monoclonal antibody directed at gross cystic disease fluid protein-15 (GCDFP-15). The diagnosis of EMP has been previously established for all cases using histochemical and immunohistochemical stains. Six of our 26 cases had a concomitant underlying carcinoma (one transitional cell carcinoma of the bladder, four adenocarcinomas of the rectum, one adenosquamous carcinoma. Only one of these six cases showed reactivity with GCDFP-15. In contrast, 16 of 20 cases of EMP without associated internal malignancy were strongly reactive with GCDFP-15 (> 5% of tumor cells). Variable GCDFP-15 reactivity in cases of EMP with and without associated internal malignancy supports the concept that EMP is a heterologous disorder. Positive GCDFP-15 in a patient with EMP may indicate a low probability of associated internal malignancy and may provide valuable clinical information.

Sebaceous carcinoma of the parotid gland

A report of an 87-year-old Caucasian female with an extensive sebaceous carcinoma of the parotid gland is presented. The computed tomographic characteristics of this rare neoplasm are reported for the first time.

Sebaceous carcinoma of the vulva

Extraocular sebaceous carcinoma (SC) is a rare tumor usually found on the head and neck. A 78 year old Japanese female who had an asymptomatic vulvar tumor is reported here. The excised specimen showed SC with metastasis to the inguinal lymph nodes. This is the fourth reported case of SC arising from female genitalia, and the second case that apparently arose from the labia minora. Contrary to the previously reported cases, tumor cells in the present case had abundant glycogen. Thus, differential diagnosis of SC from metastatic renal cell carcinoma is difficult morphologically because both of them have glycogen and lipid. Intraepidermal invasion of tumor cells has been reported in SC, but a suspected lesion of this phenomenon in the present case was proved to be histiocytic infiltration by immunohistochemistry using anti-CD 68 antibody.