Cutaneous sebaceous carcinoma

Extra-Ocular Sebaceous Carcinoma in Situ of the Arm of an Elder Male: An Unusual Presentation in an Atypical Location

Background. Sebaceous carcinoma in situ outside the ocular region is an exceedingly uncommon. It is an intraepidermal neoplasm originating from sebaceous glands limited to the epidermis with no invasion into the underlying dermis or beyond. Although sebaceous carcinoma in situ is predominantly observed in ocular regions, particularly the eyelids, instances of its occurrence in extraocular locations are infrequent, with only a limited number of examples reported in the literature. Case Presentation. A 63-year-old man presented with a left posterior arm lesion. Microscopic examination revealed a proliferation of poorly differentiated atypical neoplastic sebocytes confined to the epidermis with pleomorphic nuclei, prominent nucleoli, and clear cell changes. The neoplastic cells demonstrated positive staining for adipophilin, androgen receptor, epithelial membrane antigen, P63, BerEP4, and keratin 7. Microsatellite instability markers showed preserved nuclear staining for MLH1, PMS2, MSH2, and MSH6. A definitive diagnosis of sebaceous carcinoma in situ was rendered. Discussion. The distinctive histopathologic characteristics typically involve the presence of atypical sebaceous cells confined within the epidermis. Atypical cells often exhibit enlarged nuclei, increased mitotic activity, and prominent nucleoli. A panel of epithelial membrane antigen, adipophilin, and androgen receptors is essential for ensuring an accurate diagnosis. Conclusion. This report underscores the importance of considering sebaceous carcinoma in situ in diagnosis in atypical locations, emphasizing the need for a comprehensive histopathologic examination and immunohistochemical staining panel. This article aims to demonstrate the rarity of sebaceous carcinoma in situ in extraocular sites to broaden our understanding of its diverse clinical presentations.

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.

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.

Sebaceous Carcinoma of the Wrist in an Elderly Woman: A Case Report

Sebaceous carcinoma is a rare, aggressive cutaneous malignancy most commonly arising from the periocular area. Extraocular locations of sebaceous carcinomas, particularly outside of the head and neck region, are rare and not well-described. We report a case of an 89-year-old Caucasian female with sebaceous carcinoma of the right wrist. She initially presented with a 1.2-centimeter friable nodule on the right wrist. Initial shave biopsy and subsequent pathologic evaluation revealed a basaloid neoplasm with sebaceous differentiation, atypia, and frequent mitoses, consistent with sebaceous carcinoma. The presented case reviews common clinical features and the pertinent histopathology of ocular and extraocular sebaceous carcinoma and provides a literature review of diagnosis, prognosis, and treatment.

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

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

Impaired Wnt/beta-catenin and protein patched homolog 1 signaling in extraocular sebaceous carcinoma: A clinical and histopathological study

Sebaceous carcinoma (SC) is a rare malignant neoplasm with sebaceous differentiation. SC is classified into eyelid and extraocular SC clinically. Most studies have focused on the eyelid SC in terms of pathogenesis, treatment, and prognosis. In skin, Wnt/beta-catenin and hedgehog signaling are two major pathways in sebaceous differentiation. We aimed to characterize the clinical and histopathological features of extraocular SC and to measure the expression of beta-catenin, lymphoid enhancer-binding factor 1 (LEF1), sonic hedgehog (Shh), and protein patched homolog 1 (PTCH) in extraocular SC. Ten cases of extraocular SC were identified from 2007 to 2020. The clinical features, microscopic findings, and prognosis were analyzed. Immunohistochemical stain for beta-catenin, LEF1, Shh, and PTCH were performed in extraocular SC and other benign sebaceous tumors including sebaceous hyperplasia, sebaceous adenoma, and sebaceoma. The male:female ratio was 4:6. The median onset age was 73.5 years (range, 43-88). Seven patients out of 10 were diagnosed after 60 years. Most extraocular SC were located on the head and neck with indurated plaque. Two patients had concurrent internal cancers and three patients showed lymph node metastasis at time of presentation. Five-year overall-survival was 40%. Beta-catenin was expressed membranously in all sebaceous hyperplasia, but was expressed variably in extraocular SC (1/5). While LEF1 was unequivocally expressed in normal hair follicles, LEF1 expression was absent in all extraocular SC and benign sebaceous tumors. Regarding the sonic hedgehog signaling, Shh and PTCH were all expressed in the cytoplasm of sebaceous hyperplasia, sebaceous adenoma, and sebaceoma. In contrast, PTCH was absent in all cases of extraocular SC and only 50% of the extraocular SC expressed cytoplasmic Shh. To conclude, extraocular SC commonly affects facial skin in the elderly. Inactivated Wnt/beta-catenin and aberrant hedgehog pathway may contribute to the carcinogenesis of extraocular SC. Further studies may be required to elucidate the causative mechanism of these pathways in extraocular SC.

Mitochondrially localized MPZL3 emerges as a signaling hub of mammalian physiology

MPZL3 is a nuclear-encoded, mitochondrially localized, immunoglobulin-like V-type protein that functions as a key regulator of epithelial cell differentiation, lipid metabolism, ROS production, glycemic control, and energy expenditure. Recently, MPZL3 has surfaced as an important modulator of sebaceous gland function and of hair follicle cycling, an organ transformation process that is also governed by peripheral clock gene activity and PPARγ. Given the phenotype similarities and differences between Mpzl3 and Pparγ knockout mice, we propose that MPZL3 serves as a signaling hub that is regulated by core clock gene products and/or PPARγ to translate signals from these nuclear transcription factors to the mitochondria to modulate circadian and metabolic regulation. Conservation between murine and human MPZL3 suggests that human MPZL3 may have similarly complex functions in health and disease. We summarize current knowledge and discuss future directions to elucidate the full spectrum of MPZL3 functions in mammalian physiology.