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.

Sebaceous carcinoma in a 54-year-old Black African man after cancer chemotherapy: a case report.

BACKGROUND: Sebaceous carcinoma is a very rare malignant skin adnexal tumor that is occasionally aggressive. We have not seen a case of sebaceous carcinoma in our center in the last 10 years. It is extremely rare in Black Africans. CASE PRESENTATION: We described the case of a 55-year-old man African man who presented to our ophthalmologist with complaints of growth on the right upper eyelid for 8 months. He had surgery and chemotherapy for rectal carcinoma 6 years prior to presentation and received his last dose of chemotherapy 5 years before seeing our ophthalmologist. There was a history of spontaneous unprovoked bleeding from the lesion. He subsequently underwent surgical excision under general anesthesia. Histology of the mass showed an effaced architecture due to proliferating malignant epithelial cells disposed as trabecules, solid nests, and tongues. The microscopic features of widespread multivacuolated cytoplasm of the neoplastic cells led us to conclude that the tumor was a sebaceous carcinoma. The patient is alive and well. CONCLUSION: Sebaceous carcinoma is a rare malignant skin adnexal tumor in Black Africans. It can present as an eyelid mass with spontaneous bleeding. It can follow cancer chemotherapy either because of its association with other tumors in Muir-Torre syndrome or because of mutagenic effects of chemotherapeutic agents.

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.

Cytomorphological features of sebaceous carcinoma of the breast.

Sebaceous carcinoma of the breast is an extremely rare histological subtype of breast cancer, with fewer than 30 cases reported to date. Because of its extremely rare histological presentation, there are few case reports that highlight its cytological findings. In this case report, the cytomorphological features of a sebaceous carcinoma of the breast are described in detail. Cytomorphological analysis revealed atypical cells presenting predominantly as loose clusters. No tubular or papillary structures were evident in the clusters and no mucin production was observed. The diagnosis of sebaceous carcinoma of the breast requires prominent sebaceous differentiation of cells. In Papanicolaou-stained smears, the differentiated tumor cells were found within the yellowish clusters. When these yellowish clusters were observed at high magnification and shifted out of focus, the sebaceous differentiation of tumor cells could be recognized. This finding is an advantage of observing Papanicolaou-stained specimens. Like previous reports, some individual cells showing sebaceous differentiation were also observed. In cases where many yellowish clusters appear, close observation of the interior of the clusters can confirm the presence of sebaceous differentiation of tumor cells and serve as a diagnostic clue for the cytological diagnosis of sebaceous carcinoma of the breast.

Extra-ocular sebaceous carcinoma - A rare case report.

Sebaceous gland carcinoma is a rare and aggressive skin cancer derived from the sebaceous glands. Sebaceous carcinomas are divided into those occurring in ocular (75%) and extra-ocular locations. A 45-year-old female patient presented with rapidly growing swelling over the upper back region. It was provisionally diagnosed as an infected sebaceous cyst, and an excision biopsy was received in the pathology department. Histopathology was reported as sebaceous carcinoma, Grade II, Stage P T3 Nx. Immunohistochemistry was positive for epithelial membrane antigen. Sebaceous carcinoma accounts for 0.2-4.6% of all malignant cutaneous neoplasms, and the estimated rate of occurrence is only 1-2 per 1 million individuals per year. These tumors frequently present with a painless sub-cutaneous nodule, but they can also present as pedunculated lesions, irregular mass, or diffuse thickening of the skin. Hence, they are misinterpreted as other benign tumors or inflammatory conditions, thereby leading to delay in diagnosis, inappropriate treatment, increased morbidity, and mortality.

Mosaic Muir Torre Syndrome: Keratoacanthoma as a Piece of the Puzzle.

ABSTRACT: Lynch syndrome is an inherited condition, which increases the risk of numerous visceral malignancies and cutaneous tumors such as keratoacanthomas and sebaceous tumors. It is typically identified by immunohistochemistry of tissue taken from tumors or through genetic testing with next-generation sequencing. Diagnosing Lynch syndrome becomes more complex when the individual is mosaic for the relevant pathogenic variant. There are very few cases of this reported in the medical literature. It is even more unusual for the diagnosis to be made based on testing of a keratoacanthoma lesion. We report a case where immunohistochemistry of a keratoacanthoma helped make a diagnosis of mosaic Lynch syndrome. We will explore how mosaicism should be considered when a phenotype is strong, even if next-generation sequencing reports no pathogenic or likely pathogenic variant and how lesions such as keratoacanthomas can have a role in the early detection and treatment of future malignancies.

Nectin-4 expression in a subset of cutaneous adnexal carcinomas: A potential target for therapy with enfortumab vedotin.

BACKGROUND: Enfortumab vedotin (EV) is an antibody-drug conjugate directed against Nectin-4 that is used to treat urothelial carcinoma. Nectin-4 is inherently expressed in the skin and adnexal structures. Since therapeutic options for cutaneous adnexal carcinomas are limited, we sought to evaluate Nectin-4 expression in adnexal carcinomas and benign adnexal neoplasms to identify tumors that are potentially targetable with EV. METHODS: Eight sebaceous carcinomas (seven periocular and one lymph node metastasis), eight digital papillary adenocarcinomas, seven squamoid eccrine ductal carcinomas, eight poromas, eight trichilemmomas, and seven sebaceous adenomas were subjected to immunohistochemical staining for anti-Nectin-4 antibody. H-scores for Nectin-4 expression were calculated. RESULTS: Benign adnexal neoplasms had a significantly lower mean (±SD) Nectin-4 H-score (142.6 ± 39.1) than did the adnexal carcinomas (198 ± 90.8; p = 0.006). Nectin-4 was expressed in 91% (21/23) of adnexal carcinomas. Sebaceous carcinomas frequently exhibited high expression of Nectin-4 (88% [7/8]), with a mean (±SD) H-score (258.1 ± 58.4) significantly higher than those for digital papillary adenocarcinomas (197.5 ± 52.5; p = 0.035) and squamoid eccrine ductal carcinomas (131.4 ± 114.1; p = 0.031). Sebaceous carcinomas also had significantly higher H-scores than did sebaceous adenomas (186.4 ± 25.0; p = 0.013). CONCLUSIONS: Increased Nectin-4 expression in a subset of cutaneous adnexal carcinomas, particularly sebaceous carcinomas, reveals that EV is a potential therapeutic option for these tumors.

Diagnosis and treatment of malignant eyelid tumors.

BACKGROUND: Malignant tumors of the eyelid are much less frequent than benign eyelid alterations. These are frequently incidental findings without symptoms which are often overlooked or misinterpreted by patients. OBJECTIVE: This article gives an overview of clinical aspects, diagnostics and treatment of the five most common malignant eyelid tumors and exemplarily explains the essential principles of evidence-based treatment of malignant eyelid tumors. METHODS: This narrative review was prepared based on a selective literature search. The depiction of the treatment of eyelid tumors is supported by illustrations of clinical cases. RESULTS: The medical history and inspection provide initial indications of malignancy. Every eyelid change suspected of being malignant should be examined histologically to confirm a diagnosis. By far the most common malignant eyelid tumor in Europe is basal cell carcinoma, which metastasizes only in exceptional cases. Squamous cell carcinomas, sebaceous adenocarcinomas, melanomas and Merkel cell carcinomas occur much less frequently. In these cases, potential metastasis in particular must be considered when making the diagnosis and staging has to be initiated. Surgical excision into healthy tissue with tumor-free margins is the gold standard for malignant eyelid tumors. Non-surgical adjuvant or neoadjuvant forms of evidence-based treatment can be initiated based on the individual case to minimize the risk of recurrence and metastasis. CONCLUSION: It is essential to recognize eyelid changes at an early stage, to classify them correctly and to initiate the appropriate treatment. The interaction between the general condition and the personal needs of a patient as well as state of the art medicine are the keys to a good personalized treatment.

Apocrine carcinoma with marked sebocyte-like cytological features: A report of two cases.

Apocrine carcinoma cases with sebaceous differentiation have not been reported and can be misdiagnosed as sebaceous carcinoma. We present two cases of apocrine carcinoma with marked sebocyte-like cytological features. Tumors were observed in the left axilla of a 68-year-old man (Case 1) and the right axilla of a 72-year-old man (Case 2). Both patients presented with multiple lymph node metastases. Histopathology revealed densely distributed solid nests of tumor cells containing foamy cytoplasm and enlarged round nuclei with prominent nucleoli. The tumor cells diffusely expressed adipophilin, PRAME (cytoplasmic pattern), androgen receptor, BerEP4, and GCDFP15 but did not express p63 in both cases. PIK3CA E726K and H1047R mutations were detected in Cases 1 and 2, respectively. Tumor location in the axilla, the presence of eosinophilic granular cytoplasm, prominent nucleoli, and PIK3CA mutations, immunoreactivity for BerEP4 and GCDFP15, and lack of p63 immunoexpression findings matched apocrine carcinoma characteristics, but not sebaceous carcinoma. Thus, apocrine carcinoma can demonstrate intracytoplasmic lipid accumulation and rarely exhibit sebocyte-like cytological features. Apocrine carcinoma should be distinguished from sebaceous carcinoma due to the former's higher metastatic potential and lack of association with Muir-Torre syndrome.

Neoadjuvant Chemotherapy in a Case of Nonresectable Papillary Squamous Cell Carcinoma of the Palpebral Conjunctiva.

The role of neoadjuvant chemotherapy (NACT) in eyelid and orbital malignancies is not well defined. It has been tried with good success in cases of eyelid sebaceous gland carcinoma but there is very limited literature on its role in cases of ocular surface squamous neoplasia. A 54-year-old man presented with gradually increasing swelling of the right upper eyelid for the past 2 years. On examination, a large friable papillary mass was found covering the entire conjunctival surface (T3N0M0). Incisional biopsy from the mass was suggestive of papillary squamous cell carcinoma. There was no lymph node or distant metastasis as confirmed by whole-body positron emission tomography-CT scan. A trial of NACT (3 cycles of paclitaxel and cisplatin) was given and the mass shrunk in size considerably making it amenable to surgical resection. The conjunctival surface healed completely and there was no recurrence at 1 year of follow up. NACT can be tried in unresectable large ocular surface neoplasia to make the tumor more amenable to surgical resection.

Intraoral sebaceous carcinoma: A rare presentation on the tongue and review of the literature.

Intraoral sebaceous carcinoma (SC) is exceedingly rare, especially in the tongue. We reported the clinicopathological and immunohistochemical features of a rare SC case in a 59-year-old male who presented a painful ulcer on the tongue's posterior region. Microscopically, the tumor was composed of atypical basaloid cells with round to oval nuclei and prominent nucleoli arranged in lobes showing prominent sebaceous differentiation and areas of holocrine secretion. Immunohistochemistry showed positivity for pan-cytokeratin AE1/AE3 and epithelial membrane antigen (EMA) and negativity for cytokeratin 7 (CK7). The sebaceous cells were positive for adipophilin and perforin. Wide surgical excision followed by adjuvant chemotherapy and radiotherapy was performed. Careful histopathological analysis of these lesions is crucial to ensure a correct diagnosis. Due to the aggressive behavior of SCs, early diagnosis and treatment are essential to increase the patient's survival time. To the best of our knowledge, this is the second case of SC in the tongue.

Sebaceous carcinoma: an updated review of pathogenesis, diagnosis, and treatment options.

Sebaceous carcinoma (SC) is a very rare and aggressive form of skin cancer that arises from the sebaceous glands. SC can occur anywhere on the body, but most commonly affects the head and neck, especially the upper eyelid. SC is the third most common malignancy of the eyelid and has the potential to metastasize and be fatal; therefore, it is vital for dermatologists to remain acquainted with this malignancy and its most current treatment options. Most commonly presenting as a painless lump or thickening of skin on the eyelid, SC has an insidious progression that may not prompt the patient to seek medical attention immediately. To avoid the potential of metastasis, early diagnosis and treatment is paramount. To assess if the cancer has spread, ophthalmology, imaging, and sentinel lymph node biopsy are recommended. This article provides a comprehensive review of SC's pathogenesis, current diagnostic methods, and treatments, including wide local excision, Mohs micrographic surgery, orbital exenteration, radiation, and other topicals. The prognosis of SC depends on several factors, including size, location, stage, and treatment method. After treatment of the neoplasm, diligent post-treatment surveillance remains the cornerstone of patient care. Continued dermatologic follow-ups are essential for early detection of reoccurrence, ensuring timely intervention and optimal long-term outcomes. In conclusion, this comprehensive review aims to equip dermatologists and other physicians with a nuanced understanding of SC, enabling them to provide effective care to support patients encountering this malignancy.

Clinical Outcomes in Sebaceous Carcinoma: A Retrospective Two-Center Cohort Study.

BACKGROUND: Sebaceous carcinoma (SC) is a rare, potentially recurrent, and life-threatening cutaneous malignancy that can be associated with Muir-Torre syndrome (MTS), a DNA mismatch repair-driven genodermatosis. Earlier studies examining factors associated with recurrence have focused on periocular tumors only. OBJECTIVE: Examine outcomes of SC and identify factors associated with recurrence. MATERIALS AND METHODS: Retrospective study from 2 tertiary care centers. RESULTS: Sixty-seven cases from 63 patients were identified, including 7 cases of MTS and 13 arising in the context of immunosuppression. Fifty-five cases (82.1%) were treated with complete circumferential peripheral and deep margin assessment (CCPDMA) methods. Five recurrences developed during the postoperative period. On univariate analysis, periocular location (odds ratio [OR] 7.6, p = .0410), and lesion size ≥2 cm (OR 9.6, p = .005) were associated with recurrence, whereas CCPDMA (OR 0.052, p = .0006) was inversely associated with recurrence. On multivariate analysis, only lesion size ≥2 cm (OR 9.6, p = .0233) and CCPDMA approaches (OR 0.052, p = .007) were significant. CONCLUSION: Non-complete circumferential peripheral and deep margin assessment methods and large lesion size were independent risk factors predicting recurrence, whereas anatomic subtype and MTS status were not. These findings can assist in identifying SC cases that may benefit from more aggressive treatment and closer surveillance.

Base-Excision Repair Mutational Signature in Two Sebaceous Carcinomas of the Eyelid.

Personalized medicine aims to develop tailored treatments for individual patients based on specific mutations present in the affected organ. This approach has proven paramount in cancer treatment, as each tumor carries distinct driver mutations that respond to targeted drugs and, in some cases, may confer resistance to other therapies. Particularly for rare conditions, personalized medicine has the potential to revolutionize treatment strategies. Rare cancers often lack extensive datasets of molecular and pathological information, large-scale trials for novel therapies, and established treatment guidelines. Consequently, surgery is frequently the only viable option for many rare tumors, when feasible, as traditional multimodal approaches employed for more common cancers often play a limited role. Sebaceous carcinoma of the eyelid is an exceptionally rare cancer affecting the eye's adnexal tissues, most frequently reported in Asia, but whose prevalence is significantly increasing even in Europe and the US. The sole established curative treatment is surgical excision, which can lead to significant disfigurement. In cases of metastatic sebaceous carcinoma, validated drug options are currently lacking. In this project, we set out to characterize the mutational landscape of two sebaceous carcinomas of the eyelid following surgical excision. Utilizing available bioinformatics tools, we demonstrated our ability to identify common features promptly and accurately in both tumors. These features included a Base-Excision Repair mutational signature, a notably high tumor mutational burden, and key driver mutations in somatic tissues. These findings had not been previously reported in similar studies. This report underscores how, in the case of rare tumors, it is possible to comprehensively characterize the mutational landscape of each individual case, potentially opening doors to targeted therapeutic options.

Immunohistochemistry, Molecular Biology, and Clinical Scoring for the Detection of Muir-Torre Syndrome in Cutaneous Sebaceous Tumors: Which Strategy?

BACKGROUND: Sebaceous neoplasms (SNs) always raise the possibility of an association with Muir-Torre syndrome (MTS) and permit to screen internal malignancies, colorectal and endometrial carcinomas, before they become symptomatic. Immunohistochemistry (IHC), molecular biology, and clinical examination are different approaches for detection of MTS. We conducted a retrospective analysis of non-selected SNs in order to determine the optimal tools to implement for MTS screening. METHODS: Deficient MMR phenotype (dMMR) was determined by either IHC using antibodies directed to four mismatch repair (MMR) antigens on tissue microarray or molecular biology using pentaplex PCR. The Mayo Clinic risk score of MTS was calculated from medical records. Sensibility and specificity of each test for the detection of MTS were determined. RESULTS: We included 107 patients, 8 with multiple SNs, for a total of 123 SNs (43 sebaceous adenomas, 19 sebaceomas, and 61 sebaceous carcinomas (SC)). Loss of at least one MMR protein was observed in 70.7% of tumors, while 48% had a microsatellite instable phenotype. Concordance between both techniques was 92.9%, with a 0.85 Cohen's kappa coefficient. Nineteen patients (20.2%) had a ≥2 points Mayo Clinic risk score, one having a pMMR SC. Among the 13 patients with confirmed MTS, 2 had a low Mayo Clinic risk score (1 point). IHC had the highest sensitivity for MTS screening (100%) with a specificity of 34.1%, while a >2-point Mayo Clinic risk score had a lower sensitivity (92%) but a higher specificity (89%). CONCLUSION: To detect MTS in SN patients, the first-line Mayo Clinic risk score followed by IHC appears to be the most accurate strategy with lower cost for society. This strategy should be adapted to the medico-economic resources of each country.

Muir-Torre syndrome and recent updates on screening guidelines: The link between colorectal tumors and sebaceous adenomas in unusual locations.

BACKGROUND: Muir-Torre syndrome (MTS) is a rare genetic disorder that is caused by mismatch repair (MMR) protein mutations. MTS increases the risk of developing skin and gastrointestinal tumors such as sebaceous adenomas (SAs), sebaceous carcinomas, colorectal cancer, endometrial cancer, and ovarian cancer. The risk of developing these types of tumors varies depending on the involved mutation and the individual's family history risk. CASE PRESENTATION: A 47-year-old male presented with multiple skin lesions on the scalp, face, flank, and back. The examination revealed well-circumscribed, dome-shaped papules with a yellowish appearance with white oily material in the center. Histopathologic examination showed a well-circumscribed sebaceous neoplasm consistent with a mixture of basaloid cells and lobules of bland-appearing mature adipocytes that communicate directly to the surface epithelium. Focal cystic changes and peritumoral lymphocytic infiltrate were noted. Increased mitotic figures were seen in the basaloid cell component. The overall findings were consistent with the diagnosis of SAs. MMR staining showed preserved expression in MLH1 and PMS2 proteins, while MSH2 and MSH6 staining showed loss of protein expression. A screening colonoscopy showed numerous colon and rectal tumors, prompting concerns about the likelihood of MTS. Surgical intervention was pursued for complete resection. Histology revealed a diagnosis of mucinous adenocarcinoma/adenocarcinoma with mucinous features of the colon. The diagnosis of MTS was supported by molecular testing that revealed MSH2 germline mutation. The increased likelihood of MTS was attributed to the occurrence of SAs in unusual locations of the head and neck regions, unlike typical cases. CONCLUSION: MTS is a rare clinical condition that necessitates prompt thorough evaluation and periodic surveillance. When SA is encountered in atypical locations, it is important to consider additional testing supported by immunohistochemical staining, molecular testing, and regular screening to exclude the likelihood of MTS.