Sebaceous Carcinoma Arising in Nevus Sebaceus of Jadassohn: A Clinicopathological Study of Five Cases

Rate of Benign and Malignant Secondary Tumors Associated With Nevus Sebaceous: A Systematic Review and Meta-Analysis

BACKGROUND

Nevus sebaceous (NS) is a rare congenital skin lesion affecting approximately 0.3% of all newborns. Although benign, NS lesions can harbor malignant secondary tumors. The published rate of development of these malignant tumors varies. This meta-analysis aimed to identify the rate of malignant and benign secondary neoplasms occurring in NS.

METHODS

A literature search was conducted using PubMed, Embase, and Web of Science from inception to April 2023. Eligible studies reported incidence or risk of secondary neoplasms in patients with NS. Two independent reviewers screened studies, extracted data, and assessed the quality of included studies. The primary outcome was the pooled incidence of secondary neoplasms. Studies with sample sizes greater than 50 patients were eligible for meta-analysis using the random-effects model.

RESULTS

Twenty-eight studies were identified, 22 of which were eligible for meta-analysis. The overall rate of secondary neoplasms was 12.8% (95% confidence interval [Cl], 9.2%-17.6%). The rates of development of malignant and benign tumors were 2.4% (95% CI, 1.4%-4.1%) and 10.3% (95% CI, 7.5%-13.9%), respectively. The rate of development of basal cell carcinoma was 1.7% (95% CI, 0.9%-3.2%), whereas the rate of the development of syringocystadenoma papilliferum was 3.6% (95% CI, 2.5%-5.3%) and that if trichoblastoma was 2.6% (95% CI, 1.7%-3.8%).

CONCLUSIONS

Although the rate of development of malignant tumors within a primary NS lesion is low, it is not negligible. Prophylactic early excision remains a viable approach to prevent secondary malignant neoplasms, address cosmetic and functional complications, and preempt the need for complex reconstruction in the future. We propose that resection of NS lesions in childhood remains a reasonable first-line option in the appropriate patient keeping in mind that it may leave an undesirable scar.

S1-Guideline Sebaceous Carcinoma

Sebaceous gland carcinomas are rare malignant cutaneous adnexal tumors with sebocytic differentiation. The typical predilection area is the head and neck region, where sebaceous gland carcinomas are the most common malignant adnexal tumors of the skin. According to their localization a distinction is made between periocular and extraocular sebaceous gland carcinomas. Muir-Torre syndrome (MTS) should always be ruled out if it is suspected. In terms of prognosis, sebaceous gland carcinomas are potentially aggressive tumors with a clear tendency to recur and metastasize. Only small extraocular sebaceous gland carcinomas that have been completely resected have a very good prognosis. Sebaceous gland carcinomas most frequently metastasize lymphogenously to regional or distant lymph nodes; organ metastasis occurs less frequently. Periocular sebaceous gland carcinomas have a higher metastasis rate (up to 15%) than extraocular sebaceous gland carcinomas (up to 2%). Complete micrographically controlled surgery (MCS) of the primary tumor is the therapy of first choice, regardless of periocular or extraocular localization. Adjuvant or therapeutic radiotherapy may be considered. There is currently no established standard therapy for advanced, inoperable, or metastatic sebaceous gland carcinomas. Local procedures and systemic therapies such as chemotherapy or immunotherapy can be considered. The procedure should be determined individually by an interdisciplinary tumor board. Close follow-up care is recommended for these potentially aggressive carcinomas.

S1‐Leitlinie Talgdrüsenkarzinom

Sebaceous gland carcinomas are rare malignant cutaneous adnexal tumors with sebocytic differentiation. The typical predilection area is the head and neck region, where sebaceous gland carcinomas are the most common malignant adnexal tumors of the skin. According to their localization a distinction is made between periocular and extraocular sebaceous gland carcinomas. Muir-Torre syndrome (MTS) should always be ruled out if it is suspected. In terms of prognosis, sebaceous gland carcinomas are potentially aggressive tumors with a clear tendency to recur and metastasize. Only small extraocular sebaceous gland carcinomas that have been completely resected have a very good prognosis. Sebaceous gland carcinomas most frequently metastasize lymphogenously to regional or distant lymph nodes; organ metastasis occurs less frequently. Periocular sebaceous gland carcinomas have a higher metastasis rate (up to 15%) than extraocular sebaceous gland carcinomas (up to 2%). Complete micrographically controlled surgery (MCS) of the primary tumor is the therapy of first choice, regardless of periocular or extraocular localization. Adjuvant or therapeutic radiotherapy may be considered. There is currently no established standard therapy for advanced, inoperable or metastatic sebaceous gland carcinomas. Local procedures and system therapies such as chemotherapy or immunotherapy can be considered. The procedure should be determined individually in an interdisciplinary tumor board. Close follow-up care is recommended for these potentially aggressive carcinomas.

Nevus Sebaceous of the Scalp With Stepwise Progression Into Invasive Syringocystadenocarcinoma Papilliferum

Syringocystadenocarcinoma papilliferum (SCACP), the malignant counterpart of syringocystadenoma papilliferum (SCAP), is an extremely rare malignant adnexal neoplasm. It is described by the World Health Organization as a malignant transformation of SCAP occurring in middle-aged to elderly individuals with a predilection for the head and neck. SCACP seems to arise from a long-standing syringocystadenoma probably on a background of nevus sebaceous (NS) through a multistep progression. A 75-year-old man was referred to our department with a long-standing NS with a recent newly developing nodule on his scalp. The tumor was excised. On histology, the overall architecture of the tumor still resembled an unusual SCAP within NS but simultaneously showed transition to syringocystadenocarcinoma papilliferum in situ and invasive SCACP as recognizable by the presence of areas of nuclear atypia, increased proliferative activity, and infiltrative growth. In summary, we report an extremely rare case of an invasive SCACP of the scalp that demonstrates histological evidence for all transitive steps in the hypothetical multistep progression from NS to invasive SCACP in one single lesion. The implications of these findings are discussed in the light of the relevant literature.

A Rare Occurrence of Sebaceous Carcinoma, Sebaceoma, Syringocystadenoma Papilliferum, and Trichoblastoma in a Single Nevus Sebaceous Lesion

Nevus sebaceous (NS) is a benign tumor with the potential to develop secondary benign and malignant neoplasms. It is a rare phenomenon to develop 2 or more skin tumors in a single NS lesion. We report a case of multiple secondary tumors, such as sebaceoma, sebaceous carcinoma, syringocystadenoma papilliferum, and trichoblastoma, in a single NS lesion.

Sebaceous carcinoma arising from sebaceoma

Sebaceous neoplasms are rare adnexal tumors that can present a challenge to clinicians. Only four cases of sebaceous carcinoma with sebaceoma have been reported in the literature. Herein, we describe the case of a sebaceous carcinoma originating from a sebaceoma in a solitary nodule of the posterior neck. Immunohistochemically, the tumor cells were strongly positive for epithelial membrane antigen and p53. It is possible that adnexal carcinomas may arise from malignant transformation of their benign counterparts as well as de novo. Malignant transformation was likely in this case because the lesion was composed of distinct benign and malignant components, and the benign component showed the typical histopathological features of sebaceoma. This case underscores the fact that partial and superficial biopsies sometimes may not provide the correct diagnosis. If a surgeon suspects malignancy based on a clinical examination, then it is mandatory to perform a deep biopsy.

Sebaceous Tumors of the Skin: A Study of 145 Lesions From 136 Patients Correlating Pathologic Features and DNA Mismatch Repair Staining Pattern

ABSTRACT

Sebaceous neoplasms occur sporadically or in the setting of Muir-Torre syndrome. The data regarding the correlation of pathologic features and DNA mismatch repair (MMR) staining pattern in sebaceous tumors of the skin are very scanty and based on relatively small series of patients. The goal of this study was to correlate MMR staining pattern with selected morphological features in a series of 145 sebaceous neoplasms (sebaceous adenoma, sebaceoma, and extraocular sebaceous carcinoma) from 136 patients. Cystic change, intratumoral mucin deposits, squamous metaplasia in the absence of keratoacanthoma-like changes, ulceration, intratumoral and peritumoral lymphocytes (in cases without epidermal ulceration), and intertumoral heterogeneity proved to be significantly associated with MMR deficiency. Identification of any of these changes, alone or in combination, should prompt further investigation of the patient to exclude Muir-Torre Syndrome. Our study also confirms the previously published observation that the diagnosis and tumor location are significantly associated with MMR deficiency.

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.

Impact of surgery and adjuvant treatment on the outcome of extraocular sebaceous carcinoma: a systematic review and individual patient's data analysis of 206 cases

BACKGROUND

Extraocular sebaceous carcinoma (EOSC) is an aggressive malignancy of the sebaceous gland. Surgery is considered the cornerstone of treatment, but there is lack of clarity about extent and adjuvant treatment.

METHODS

We conducted a systematic review and analysis of individual patient data of all published cases of EOSC to look into demography, pattern of care, importance of type of surgery, and other adjuvant treatment and survival outcome. A search of PubMed and Google Scholar was done with the key words sebaceous carcinoma, extraocular sebaceous carcinoma, and Muir-Torre syndrome till December 2017. The data were compiled in an Excel chart and analyzed using SPSS IBM software.

RESULTS

Data of 206 patients were retrieved. Median age at presentation was 65 years (range: 11-96 years). Surgery was performed in all except 13 patients. Of these 13, eight were deemed inoperable for extensive disease, and five had metastatic disease. Median PFS and OS for the entire cohort were 84 months (95% CI: 10-158 months) and 92 months (95% CI: 59-126 months). Univariate analysis revealed significantly poor survival for patients with a metastatic disease, regional nodal metastasis, and those with Mohs micrographic or incomplete surgery.

CONCLUSION

EOSC is a disease of elderly patients with good prognosis. Complete surgery with regional lymph node dissection is standard treatment. The role of adjuvant radiotherapy is debatable but can be considered in patients with incomplete surgery or high-risk factors.

Sebaceous lesions of the skin

Sebaceous differentiation is commonly seen in cutaneous neoplasms, both in the context of lesions showing predominantly sebaceous differentiation (e.g., sebaceous adenoma, sebaceoma and sebaceous carcinoma), or as more focal sebaceous components in neoplasms with other primary lines of differentiation. Sebaceous changes can also be a component of benign cystic lesions or epidermal tumours, and sebaceous hyperplasia is commonly encountered. This review is intended to provide an overview of the cutaneous lesions with sebaceous differentiation, with a particular emphasis on facilitating histological diagnosis of neoplasms. In addition, the role of immunohistochemical studies is outlined, as well as the evaluation of potential cases of Muir-Torre syndrome.

Sebaceous Neoplasms

Sebaceous skin tumors are classified into sebaceous adenoma, sebaceoma, and sebaceous carcinoma. An additional group of cystic sebaceous tumors indicate the Muir-Torre syndrome (MTS). Cystic sebaceous tumors are considered as morphologic variants of the 3 main categories. Multilineage adnexal tumors with partly sebaceous differentiation may pose a challenge to categorize. Sebaceous hyperplasia and nevus sebaceus are not considered as true sebaceous tumor entities. Recently, attention has been drawn to morphologic clues of sebaceous differentiation. Immunohistochemistry using the mismatch repair proteins and/or genetic microsatellite instability testing should be performed on sebaceous neoplasms to diagnose MTS as early as possible.

Syringocystadenocarcinoma papilliferum: Clinicopathologic analysis of 10 cases

BACKGROUND

Syringocystadenocarcinoma papilliferum (SCACP) is an exceedingly rare cutaneous adnexal neoplasm. We aimed to investigate the clinicopathologic and immunophenotypic features of SCACP, and to discuss the prognosis of this rare entity.

METHOD

We retrospectively collected clinical, pathological and follow-up data of 10 cases with SCACP.

RESULTS

There were 8 males and 2 females, with ages ranging from 26 to 74 years. The chest was most frequently involved. Histologically, 1 case only showed SCACP in situ, 9 cases presented with variable invasive components of adenocarcinoma and/or squamous cell carcinoma in addition to areas of in situ. Apocrine differentiation with decapitation was evident in 4 cases and mucinous metaplasia was noted in 1 case. P63 was positive in invasive squamous cell carcinoma, while CK7 was variably positive in invasive adenocarcinoma. Regional lymph node metastasis was confirmed by pathological examination in 4 patients. Follow up was available for 9 patients, ranging from 3 to 112 months. Three patients died of the disease within 1 year after recurrences.

CONCLUSIONS

Because of high rates of regional lymph node metastasis and mortality in our patients, clinical behavior of SCACP seems to be more aggressive than that previously reported.

Dermoscopic Analysis of Nevus Sebaceus of Jadassohn: A Study of 13 Cases

BACKGROUND

Nevus sebaceus of Jadassohn (NSJ) is a complex cutaneous hamartoma with various clinical appearances.

AIM

To describe different dermoscopic patterns of this nevus according to its evolutionary stages.

METHODS

This was an analytical study of NSJ carried out in the Department of Dermatology at the University Hospital Hassan II, Fez, Morocco.

RESULTS

Thirteen patients with a NSJ were enrolled in the study. Elevated verrucous plaques were noticed in 9 patients, homogeneous tumors were described in 2 NSJ, an alopecic patch was found in 1 case, and we had 1 case of malignant transformation into basal cell carcinoma. The dermoscopic aspects of NSJ described in our study were yellowish or brown globules aggregated in clusters on a yellow background. This pattern was significantly related to the first stage of an alopecic patch (p = 0.001). Whitish-yellow lobular aspect and grayish papillary appearance were significantly related to verrucous plaques (p = 0.003). Homogeneous yellow-whitish pattern was related to nodules (p = 0.005).

CONCLUSION

The establishment of specific dermoscopic features of NSJ according to its evolutionary stages is important for its diagnosis and especially its monitoring in order to detect malignant transformation.

Syringocystadenocarcinoma Papilliferum In Situ-Like Changes in Extramammary Paget Disease: A Report of 11 Cases

The authors report 11 cases of extramammary Paget disease (EMPD), all of which also demonstrated a combination of histological changes highly reminiscent of syringocystadenocarcinoma papilliferum in situ. In addition to the classical features of EMPD, characterized by the intraepidermal spread of individually dispersed neoplastic cells with ample cytoplasm, many of which contained mucin, there were areas of acanthosis with the substitution of spinous layer keratinocytes by neoplastic cells, whereas the native basal cell layer was intact. In addition to acanthosis (and sometimes papillomatosis), the dermal papillae showed a prominent infiltrate of plasma cells, completing the resemblance to syringocystadenocarcinoma papilliferum in situ; this similarity was further enhanced in 2 cases, which showed conspicuous gland formation. One additional case showed multifocal dermal proliferations compatible with eccrine syringofibroadenoma (syringofibroadenomatous hyperplasia). The changes described herein seem to be relatively rare in EMPD, and they can represent a diagnostic pitfall, as evidenced by 2 cases that were originally misinterpreted as syringocystadenocarcinoma papilliferum in situ. Clinically, these microscopic changes sometimes corresponded to nodular lesions, which were specifically noted to have a papillated erosive surface.

A Histological Snapshot of Hypothetical Multistep Progression From Nevus Sebaceus to Invasive Syringocystadenocarcinoma Papilliferum

Syringocystadenocarcinoma papilliferum (SCACP) is an extremely rare adnexal neoplasm, believed to arise in a preexisting nevus sebaceus of Jadassohn (NSJ) through a multistep progression process. This hypothetical process involves an NSJ giving rise to syringocystadenoma papilliferum, which then presumably undergoes malignant transformation in rare circumstances to give rise to SCACP in situ, which finally progresses to an invasive SCACP. Of the 30 SCACP cases reported so far, none have documented the process from a birthmark to the final invasive lesion, with histological evidence of each step, in a single tumor. Here, the authors report just such a case. A 74-year-old man presented with a recently enlarging birthmark on the scalp. Excisional biopsy showed an invasive SCACP, in the background of SCACP in situ, syringocystadenoma papilliferum, and NSJ. Furthermore, this tumor showed a concurrent pigmented trichoblastoma and histological evidence of lymphovascular invasion, events that have not been documented with SCACP. Interestingly, all these component lesions were present on a single histological section of this solitary tumor. Regional lymph node metastasis, a rare occurrence in SCACP, was also present in this remarkable case. The authors discuss the implications of these findings in light of the review of relevant literature.

Sebaceous carcinoma: review of the literature

BACKGROUND

Sebaceous carcinoma is an uncommon adnexal neoplasm with a documented capability for regional and distant metastasis. Traditionally, sebaceous carcinoma has been associated with high rates of recurrence after excision.

OBJECTIVE

To review the current literature on sebaceous carcinoma and detail its epidemiology, pathogenesis, clinical presentation, histopathology, diagnostic workup, treatment, and prognosis.

MATERIALS AND METHODS

Literature review using PubMed search for articles related to sebaceous carcinoma.

RESULTS

Sebaceous carcinoma typically presents as a painless pink or yellow nodule. Diagnosis requires histopathologic examination, and immunohistochemical analysis often assists in the differentiation of sebaceous carcinoma from other benign and malignant skin neoplasms. Sebaceous carcinoma should prompt a workup for Muir-Torre syndrome. Periorbital sebaceous carcinoma has an increased tendency for regional metastasis, although cancer-specific mortality rates are similar among all anatomic locations.

CONCLUSION

Surgery is the preferred treatment for local disease. Limited data suggest that Mohs micrographic surgery may provide superior clinical outcomes, but more research is needed regarding the long-term outcomes. Radiation and systemic chemotherapy are reserved for recurrent or metastatic disease.

A new case of syringocystadenocarcinoma papilliferum: a rare pathology for a wide-ranging comprehension

We report a new case of p63/cytokeratin 7 (CK7) positive syringocystadenocarcinoma papilliferum (SCACP), on the shoulder of an 88-year-old man, with superficial dermal infiltration and squamoid differentiation. We describe the 24th case of SCACP, the malignant counterpart of syringocystadenoma papilliferum (SCAP). At the present, we do not know whether SCACP arises from eccrine or apocrine glands because of the contrasting opinions in the literature. Only few histochemical and ultrastructural studies have previously advised that SCACP could arise from pluripotent stem cells. Through our case, we wish to suggest the stem cell-like properties of the syringocystadenocarcinoma papilliferum. This rare neoplasm shows two different patterns of stem cell marker expression in the glandular and squamous components, respectively. For the double phenotype of SCACP, we propose it like an intriguing model to study histogenesis and stem cell properties for more wide-ranging epithelial tumors.

A rare combination of sebaceoma with carcinomatous change (sebaceous carcinoma), trichoblastoma, and poroma arising from a nevus sebaceus

We report a case of a 48-year-old Malay female who presented with multiple tumors arising from a large nevus sebaceus on her right parieto-temporal scalp. Histologically, the tumors corresponded to a sebaceoma with carcinomatous change, a poroma and a trichoblastoma. Immunohistochemical staining of the sebaceous tumor with p53 showed strong within the areas of carcinomatous change, while there was negative to weak staining within the sebaceoma-like areas. A discussion on the potential secondary neoplasms from a nevus sebaceus ensues, with a review of this literature on multiple tumors from a nevus sebaceus.

Syringocystadenocarcinoma papilliferum with transition to areas of squamous differentiation: a case report and review of the literature

Syringocystadenocarcinoma papilliferum (SCACP) is an exceedingly rare cutaneous adnexal neoplasm, which is typically located in the head and neck, and perianal area. Very few cases have been reported in the literature. Here, we report a case of SCACP with evident transition to squamous differentiation. A 75-year-old white woman presented with 1-year history of a solitary tender nodule in the left upper arm. Physical examination revealed a single, 1.5 × 1.1-cm, erythematous ulcerated nodule within a background of red patch. Biopsy showed an adnexal carcinoma connected to the epidermis and composed of cystic papillary projections admixed with solid basaloid areas with marked cytologic atypia. The basaloid tumor cells appeared to blend with the squamous component that demonstrated ductal formation, which was highlighted by carcinoembryonic antigen. Tumor cells were reactive for both cytokeratins 5/6 and 7. This case represents SCACP arising from syringocystadenoma papilliferum in the upper arm, with distinct transition to areas of squamous differentiation.

Nevus sebaceous revisited

Nevus sebaceous of Jadassohn is a hamartoma with a combination of abnormalities of the epidermis, hair follicles, and sebaceous and apocrine glands. Herein, we discuss the results of an extensive literature review on the topic of nevus sebaceous with a particular focus on the debate about the necessity for prophylactic excision. We also focus on the documentation of associated malignant tumors that were reported to develop within NS. In addition to reporting the number and types of neoplasms, we documented the recommendations of all authors for therapeutic handling of these nevi.

Ripple/Carcinoid pattern sebaceoma with apocrine differentiation

Sebaceoma is a benign sebaceous neoplasm, which has been reported to show characteristic growth patterns, such as, ripple, labyrinthine/sinusoidal, and carcinoid-like patterns. Another recent finding regarding in sebaceoma is the observation of apocrine differentiation within the sebaceoma lesion. This report describes a case of carcinoid (a partial ripple and labyrinthine) pattern sebaceoma with apocrine differentiation with a literature review and immunohistochemical studies. The various characteristic growth patterns in sebaceoma were suggested to simply be variations of the same growth pattern arranged in cords, namely, a unified term "ripple/carcinoid pattern." The primitive sebaceous germinative cells in sebaceoma may still have the ability to undergo apocrine differentiation. Most of the reports so far on sebaceoma with apocrine differentiation, including the present case, describe a ripple/carcinoid pattern, thus suggesting that ripple/carcinoid pattern sebaceoma is composed of more primitive sebaceous germinative cells than conventional sebaceoma.

Epidermal nevi

Nevi or nests of cells may be made up of a variety of cell types. The cell types that live in the epidermis include epidermal cells or keratinocytes, sebaceous glands, hair follicles, apocrine and eccrine glands, and smooth muscle cells. This article discusses epidermal or keratinocyte nevi, nevus sebaceous, nevus comedonicus, smooth muscle hamartomas, and inflammatory linear verrucous epidermal nevi. Syndromes associated with epidermal nevi are also reviewed.

Diagnostic pitfalls in syringocystadenocarcinoma papilliferum: case report and review of the literature

We report the first case, to our knowledge, of syringocystadenocarcinoma papilliferum with p63-verified squamous differentiation and extensive dermal invasion accompanying in situ components. An 86-year-old woman presented with a neoplasm on the neck, and the intralesional heterogeneity typical of these neoplasms led to an initial diagnosis on needle biopsy favoring squamous cell carcinoma. Excision illustrated diverse morphology, raising a broad differential diagnosis, including more common extracutaneous malignancies, such as breast, gastrointestinal, and ovarian primary tumors. Fortuitous sectioning revealed a focal connection to the skin surface with evidence of apocrine differentiation allowing final diagnosis as syringocystadenocarcinoma papilliferum. Our literature review shows the histologic and immunohistochemical features of syringocystadenocarcinoma papilliferum are not well defined outside of their clear morphologic overlap with syringocystadenoma papilliferum. We describe our findings and diagnostic pitfalls to help pathologists encountering this unusual apocrine neoplasm.

Sebaceous lesions and their associated syndromes: part I

Sebaceous neoplasms have long been a source of confusion to dermatologists and pathologists alike. Disagreements regarding nomenclature, classification, and management have been longstanding. Sebaceous lesions represent a broad spectrum of interesting entities that range from hamartomas, hyperplasias, and benign tumors to highly malignant neoplasms. This article discusses the clinical and pathologic features of sebaceous hyperplasia, nevus sebaceous of Jadassohn, sebaceous adenoma, seboacanthoma, sebaceous epithelioma, sebaceoma, mantleoma, basal cell carcinoma with sebaceous differentiation, sebomatricoma (sebomatrixoma), and sebaceous carcinoma. Controversies regarding these lesions will be explored, and any relationship with Muir-Torre syndrome will be discussed.

Sebaceous carcinoma: the great masquerader: emgerging concepts in diagnosis and treatment

Sebaceous carcinoma (SC) is a rare tumor with a high rate of local recurrence and metastasis to lymph nodes and organs. The majority of SCs occur in the periocular region frequently presenting as painless, round subcutaneous nodules with a high tendency of diffuse and invasive growth in the eyelid and conjunctiva. It frequently masquerades as inflammatory conditions or as other tumors leading to delay in diagnosis, inappropriate treatment and increased morbidity and mortality. Sebaceous carcinoma is associated with Muir-Torre syndrome, a genetic condition presenting with sebaceous skin tumors associated with internal malignancy. Therefore, SC patients must be carefully evaluated and referred to an internist or gastroenterologist when indicated. Surgery is the definitive therapy for SC. In recent years, less radical surgical strategies are being used with improved outcomes. Current studies demonstrate that Mohs micrographic surgery (MMS) provides maximal tissue conservation and lower recurrence rates. Greater awareness and understanding of SC and its behavior has led to earlier diagnosis and appropriate treatment.

Spiradenoma and spiradenocylindroma with an adenomatous or atypical adenomatous component: a clinicopathological study of 6 cases

We report 5 cases of spiradenoma and 1 case of spiradenocylindroma, which, in addition to areas of conventional growth, manifested an adenomatous component. This consisted of compactly situated, well-developed glands having small round lumens lined by inner pale to eosinophilic cells and surrounded by an outer well-formed peripheral layer of myoepithelial cells, which reacted with a variety of myoepithelial cell markers. In 1 case, apocrine secretion was evident in the glandular part of the lesion. In 4 of the 6 cases, the adenomatous component was a minor but significant portion of the tumors, but in 2 cases it was extensive, comprising approximately 20% of the tumor area. In 1 of these 2 cases, the luminal epithelium showed atypia including rare, atypical mitotic figures. In addition, there were foci of glands showing myoepithelial cell loss. As this alteration was limited and fairly well circumscribed within the tumor bulk, we regard it as an "atypical adenomatous component," but we cannot exclude the possibility that this may represent an incipient apocrine carcinoma, despite uneventful follow-up. Three cases also manifested clear cell areas. Immunohistochemical studies demonstrated that myoepithelial proliferation and overgrowth accounted for the clear cell change in some of the lesions.

Squamous cell carcinoma developing in a naevus sebaceous of Jadassohn

Squamous cell carcinoma developing within a naevus sebaceus of Jadassohn is rare. We report the fifth such case in the English literature to highlight the importance of early excision of any naevus sebaceus of Jadassohn with a history of change. Other cases have been reported, but the clinical and histopathological details were not well documented.

Unusual malignant transformation of recurrent sebaceoma. A case report

Sebaceoma is a benign tumor composed of incompletely differentiated sebaceous cells of varying degrees of maturity. Sebaceomas was never reported as a known premalignant lesion.This is a report of a sixteen year old boy who presented with a malignant transformation of a recurrent sebaceoma which was excised twice by Moh's surgery. Excision was done with a free margin of 1 cm down to the parotid fascia. Reconstruction was performed on the same set by using cervicofascial flap extending down to the supra-clavicular area. The patient had an uneventful postoperative period apart from distal marginal necrosis of the flap, which healed nicely with conservative measures and daily dressing and was sent to our cancer centre to start his adjuvant radiotherapy.Previous literature stated that sebaceoma is a distinctive benign tumor. We have presented a case of an unusual malignant transformation of a preauricular recurrent sebaceoma. This indicates that sebaceoma does have a potential risk of malignant transformation. We believe that managing recurrent sebaceoma more aggressively with wide local excision and postoperative adjuvant radiotherapy would provide better prognosis.