Sebaceous carcinoma of the eyelid treated with Mohs micrographic surgery

Periocular sebaceous gland carcinoma: A comprehensive review

Sebaceous gland carcinoma (SGC) is a rare tumour occurring at periocular and extra-ocular sites. SGC can be a challenging diagnosis for both clinicians and pathologists. High recurrence rates and a tendency for intra-epithelial spread, locoregional and distant metastases make it important for SGC to be suspected and be included in the differential diagnosis of an eyelid lesion. Early diagnosis, that may sometimes need ancillary testing, and prompt management using a multimodal approach can help reduce morbidity and mortality in patients with SGC.

Current status of surgery in dermatology

An article titled "Current issues in dermatologic office-based surgery" was published in the JAAD in October 1999 (volume 41, issue 4, pp. 624-634). The article was developed by the Joint American Academy of Dermatology/American Society for Dermatologic Surgery Liaison Committee. A number of subjects were addressed in the article including surgical training program requirements for dermatology residents and selected advances in dermatologic surgery that had been pioneered by dermatologists. The article concluded with sections on credentialing, privileging, and accreditation of office-based surgical facilities. Much has changed since 1999, including more stringent requirements for surgical training during dermatology residency, and the establishment of 57 accredited Procedural Dermatology Fellowship Training Programs. All of these changes have been overseen and approved by the Residency Review Committee for Dermatology and the Accreditation Committee for Graduate Medical Education. The fertile academic environment of academic training programs with interaction between established dermatologic surgeons and fellows, as well as the inquisitive nature of many of our colleagues, has led to the numerous major advances in dermatologic surgery, which are described herein.

Nonmelanoma skin cancer

Nonmelanoma skin cancer (NMSC) is the most common form of malignancy in humans. The incidence of NMSC continues to increase despite increased awareness and sun-protective measures. If neglected or mismanaged, NMSC can cause significant morbidity and even death. The most common forms of NMSC on the head and neck include basal cell carcinoma, squamous cell carcinoma, sebaceous carcinoma, eccrine porocarcinoma, Merkel cell carcinoma, atypical fibroxanthoma, and microcystic adnexal carcinoma. Surgery is the mainstay of treatment (standard excision, Mohs micrographic surgery, curettage); however, other modalities exist, including radiation, topical immunomodulators, photodynamic therapy, and new systemic medications.

Mohs micrographic surgery of the eyelid: an overview of anatomy, pathophysiology, and reconstruction options

BACKGROUND

Mohs micrographic surgery (MMS) is the ideal treatment for skin cancer removal. The advantages of MMS in the eyelid area include its high cure rate, tissue-sparing effects, and overall cost effectiveness.

OBJECTIVE

To review eyelid anatomy, detail ocular tumors that are amenable to MMS, and examine the surgical repair options commonly used in this area.

MATERIALS AND METHODS

A review of the literature on MMS of the eyelid was performed with specific reference to ocular anatomy, eyelid malignancy types, and surgical reconstruction.

CONCLUSION

Eyelid function is critical for the maintenance of ocular health and vision. MMS is an ideal skin cancer treatment for the delicate structure of the eyelid, where maximal tissue preservation is critical. There are a plethora of reconstruction options to consider after MMS has been performed in this area. The choice of repair and surgical outcome depend, in part, on the surgeon's knowledge of eyelid anatomy and his or her ability to assess the repair requirements of the post-MMS defect. Dermatologic surgeons can effectively work with other specialists to help ensure that their patients receive a cure with restored ocular function and optimal cosmesis.

Extraocular sebaceous carcinoma: a report of 2 cases

Sebaceous carcinoma is a rare, aggressive adnexal tumor of unknown etiology; 75% of these tumors arise in the periocular region while 25% arise at extraocular sites. This cutaneous tumor is a diagnostic sign of Muir-Torre syndrome, a disorder associated with visceral malignancies and gene abnormalities. Patients with sebaceous carcinoma should therefore be carefully evaluated; a detailed personal and family history of cancer, a thorough physical examination, additional tests where appropriate, and close monitoring will all be required. We report 2 cases of extraocular sebaceous carcinoma and review the literature, focusing on the association between sebaceous carcinoma and Muir-Torre syndrome.

Uncommon cutaneous neoplasms of the head and neck

This article concentrates on the less-common cutaneous malignancies such as merkel cell, atypical fibroxanthoma, malignant fibrous histiocytoma, dermatofibrosarcoma protuberans, microcystic adnexal carcinoma, and sebaceous carcinoma. The clinical and histopathologic descriptions of each, most current and emerging etiologies, diagnosis, staging, treatment, and prognosis are discussed.

AAD/ACMS/ASDSA/ASMS 2012 appropriate use criteria for Mohs micrographic surgery: a report of the American Academy of Dermatology, American College of Mohs Surgery, American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery

The appropriate use criteria process synthesizes evidence-based medicine, clinical practice experience, and expert judgment. The American Academy of Dermatology in collaboration with the American College of Mohs Surgery, the American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery has developed appropriate use criteria for 270 scenarios for which Mohs micrographic surgery (MMS) is frequently considered based on tumor and patient characteristics. This document reflects the rating of appropriateness of MMS for each of these clinical scenarios by a ratings panel in a process based on the appropriateness method developed by the RAND Corp (Santa Monica, CA)/University of California-Los Angeles (RAND/UCLA). At the conclusion of the rating process, consensus was reached for all 270 (100%) scenarios by the Ratings Panel, with 200 (74.07%) deemed as appropriate, 24 (8.89%) as uncertain, and 46 (17.04%) as inappropriate. For the 69 basal cell carcinoma scenarios, 53 were deemed appropriate, 6 uncertain, and 10 inappropriate. For the 143 squamous cell carcinoma scenarios, 102 were deemed appropriate, 7 uncertain, and 34 inappropriate. For the 12 lentigo maligna and melanoma in situ scenarios, 10 were deemed appropriate, 2 uncertain, and 0 inappropriate. For the 46 rare cutaneous malignancies scenarios, 35 were deemed appropriate, 9 uncertain, and 2 inappropriate. These appropriate use criteria have the potential to impact health care delivery, reimbursement policy, and physician decision making on patient selection for MMS, and aim to optimize the use of MMS for scenarios in which the expected clinical benefit is anticipated to be the greatest. In addition, recognition of those scenarios rated as uncertain facilitates an understanding of areas that would benefit from further research. Each clinical scenario identified in this document is crafted for the average patient and not the exception. Thus, the ultimate decision regarding the appropriateness of MMS should be determined by the expertise and clinical experience of the physician.

Periocular cutaneous malignancies: a review of the literature

BACKGROUND

The periocular skin is susceptible to numerous benign and malignant neoplasms. Periocular malignancies may present differently, behave more aggressively, and pose greater challenges for treatment and repair than malignancies at other cutaneous sites. Between 5% and 10% of cutaneous malignancies occur periorbitally, with basal cell carcinoma reported as the most common malignant periocular tumor, followed by squamous cell carcinoma, sebaceous gland carcinoma, cutaneous melanoma, Merkel cell carcinoma, and other rare tumors.

OBJECTIVE

To review the current literature on cutaneous malignancies of the periocular region pertaining to etiology, incidence, clinical presentation, differential diagnosis, complications, and treatment options.

MATERIALS AND METHODS

An extensive literature review was conducted using PubMed, searching for articles on periocular and periorbital cutaneous malignancies.

CONCLUSIONS

Timely diagnosis and management of periocular malignancies is essential because of their proximity to and potential to invade vital structures such as the orbit, sinuses, and brain. Surgical excision remains the standard of care for the majority of periorbital malignancies, but given the sensitive anatomic location, tissue-sparing techniques with margin control such as Mohs micrographic surgery are the preferred method for most nonmelanoma skin cancers. Depending on tumor type, other treatment modalities may include radiation, chemotherapy, cryosurgery, topical medications, and photodynamic therapy.

Sebaceous carcinoma of eyelid

The authors are presenting here, a case of sebaceous carcinoma in a 50-year-old male who presented with 6-month history of a fungating mass in the right eye near medial canthus. Exenteration of eye was done, and a diagnosis of sebaceous carcinoma was made on histopathological examination.

Noninvasive and curative radiation therapy for sebaceous carcinoma of the eyelid

PURPOSE

Sebaceous carcinoma of the eyelid is a rare malignancy. Surgical excision remains the standard and most reliable curative treatment. However, surgery is sometimes not possible because many patients are elderly, and it frequently causes functional and cosmetic impairment of the eyelid. We therefore carried out a study to determine the role of radiation therapy in relation to sebaceous carcinoma of the eyelid.

METHODS AND MATERIALS

Thirteen patients with sebaceous carcinoma of the eyelid underwent radiation therapy with curative intent. There were 6 men and 7 women, and their ages at irradiation ranged from 60 to 85 years (median, 78 years). Only 1 patient had cervical lymph node metastasis, and none of the patients had distant metastasis. A total dose of 50 to 66.6 Gy (median, 60 Gy) was delivered to tumor sites in 22 to 37 fractions.

RESULTS

All irradiated tumors were controlled at a median follow-up period of 55 months. Only 1 patient had recurrence of cervical lymph node metastasis outside the radiation field, at 22 months after irradiation. The 5-year local progression-free and disease-free rates were 100% and 89%, respectively. The overall and disease-free survival rates at 5 years were 100% and 89%, respectively. Although acute and transient therapy-related reactions of Grade 2 or less were observed, there were no severe toxicities of Grade 3 or greater.

CONCLUSIONS

Radiation therapy is a safe and effective treatment for patients with sebaceous carcinoma of the eyelid. It appears to contribute to prolonged survival as a result of good tumor control, and it also facilitates functional and cosmetic preservation of the eyelid.

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.

Mitomycin-C as adjuvant therapy in the treatment of sebaceous gland carcinoma in high-risk locations

PURPOSE

To report on the use of Mitomycin-C as adjuvant therapy to excision and cryotherapy in patients with sebaceous gland carcinoma (SGC) in high-risk locations.

DESIGN

Retrospective, consecutive, case series.

PARTICIPANTS

Three patients with SGC of the upper palpebral conjunctiva or caruncle, but without clinical pagetoid spread.

METHODS

Following excision and double freeze-thaw cryotherapy, patients with histology demonstrating SGC of the ocular surface were treated with topical Mitomycin-C (0.04%). Follow-up was conducted over an average of 30 months (range: 24-37 months).

MAIN OUTCOME MEASURES

Postoperative evidence of local recurrence, lymph node or distant organ metastasis.

RESULTS

No patients had evidence of local recurrence or systemic disease.

CONCLUSIONS

Wide surgical excision with cryotherapy is the basis of treatment of SGC without pagetoid spread. The use of Mitomycin-C as adjuvant therapy remains controversial, although there is some rationale for its use in high-risk situations.

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.

Management of cutaneous tumors with mohs micrographic surgery

Since the inception of Mohs micrographic surgery in the 1930s, this technique has proved its utility in the treatment of cutaneous tumors. This review describes the technique of Mohs micrographic surgery and the various indications for which it is used. We discuss the use of Mohs micrographic surgery for the following cutaneous tumors: basal cell carcinoma, squamous cell carcinoma, melanoma in situ, dermatofibrosarcoma protuberans, Merkel cell carcinoma, microcystic adnexal carcinoma, atypical fibroxanthoma, and sebaceous carcinoma. Mohs micrographic surgery is cost effective in the U.S. health care system because billing for the surgeon-pathologist and laboratory processing is bundled together. However, Mohs micrographic surgery may be more expensive in European systems because the Mohs technique surgeon, pathologist, and laboratory fees may be billed separately.

Current progress of immunostains in Mohs micrographic surgery: a review

Mohs micrographic surgery is often considered the treatment of choice for a variety of skin malignancies. In recent years, the application of immunostaining techniques has facilitated the successful removal of a number of common and less common cutaneous malignancies, including basal cell carcinoma, squamous cell carcinoma, malignant melanoma, dermatofibrosarcoma protuberans, microcystic adnexal carcinoma, sebaceous carcinoma, atypical fibroxanthoma, extramammary Paget's disease, and even sarcomas. Immunostains highlight the tumor cells and allow the Mohs surgeons to pinpoint and eliminate the residual tumor at the surgical margin. It is especially helpful when a tumor presents with subtle or nonspecific histologic features or when a tumor is masked in a pocket of dense inflammation. However, the cost, the labor, and the time consumption are of concern to many of our peers, as are the diversity of antigens, which may overwhelm some. This article serves as a review of the literature on current uses of immunostaining in Mohs micrographic surgery and as a summary of their realistic applications in the dermatologic surgeon's practice. We conclude that immunohistochemical technique has played an important role in Mohs surgery advancement. With greater use and more cost-effective staining methods, we believe that the use of immunostains in a Mohs practice will become routine.

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.

Sebaceous carcinoma of the eyelids: a review of 21 cases

BACKGROUND

Sebaceous carcinoma is a malignant neoplasm that arises from the sebaceous glands and occurs most often in the eyelids. A tumour diameter exceeding 10mm indicates a grave prognosis. However, thus far, no study has used the T classification of the tumour, node, metastasis (TNM) staging system to determine the prognosis. In this article, we studied the management and outcomes of sebaceous carcinoma using the T classification.

METHODS

We report our experience of sebaceous carcinoma of the eyelids in 21 patients between December 1979 and December 2003. We employed the method of T classification and assessed the management and clinical outcomes in patients with sebaceous carcinoma of the eyelids.

RESULTS

The sample included three T1, six T2, five T3, and seven T4 cases. All the cases were managed by surgery. The follow-up periods ranged from 22 to 123 months. The mean and the median were 70.7 and 62 months, respectively. At the time of the last follow up, 12 of the 21 patients were alive. Five deaths were secondary to the tumour and four were unrelated. Most importantly, none of the T1, T2, or T3 patient deaths were secondary to the tumour. However, all the patients that died as a result of the tumour were of the T4 type. The cause-specific cumulative survival rate over five years was 78.9%; however, that of the T4 type was 42.9%.

CONCLUSION

None of the T1, T2, or T3 patients died as a result of the tumour, which indicates a good prognosis. However, the cases of the T4 type had a grave prognosis. Therefore, the T classification alone may be an important factor in determining the prognosis for sebaceous carcinoma of the eyelids.

A Primer of Mohs Micrographic Surgery: Uncommon Indications

Mohs micrographic surgery has been used for the treatment of tumors other than basal and squamous cell carcinomas. Parameters to be considered when deciding on a treatment include location, size, growth pattern, and recurrence rates. It is important to consider that sometimes the high-risk nature of the tumor is more significant than the need for tissue sparing. Modifications to the Mohs micrographic surgery technique may be used to ensure diagnostic accuracy and confirm complete removal of the lesion (e.g., immunohistochemical staining and paraffin-embedded sections).

Reconstruction of the levator function and conjunctiva using an inferiorly based orbital septal flap for subtotal full-thickness defects of the upper eyelid: two cases of ocular sebaceous carcinoma

Without using the lower eyelid, functional reconstruction of the tarsoconjunctival layer is challenging for subtotal full-thickness defects of the upper eyelid. In 2 cases of ocular sebaceous carcinoma, the levator function and conjunctiva were reconstructed using the inferiorly based orbital septal flap and conchal cartilage graft. The raw surface of the orbital septal flap was epithelialized within 14 days postoperatively. The new upper eyelid with a stable lid margin could open and close properly. Our surgical procedures may be available in the case that the lower eyelid is not usable.

Frozen Section Diagnosis and Indications in Ophthalmic Pathology

Context.—Frozen sections for ophthalmic tissues require very precise indications.

Objective.—To describe indications and procedures for frozen sections in ophthalmic pathology based on review of my experience and reports in the literature.

Design.—Frozen sections received by the ophthalmic pathology service at The Methodist Hospital from 1996 to 2004 were reviewed. A review of the literature also was performed.

Results.—Of the 277 specimens received, most were eyelid lesions (138, 49.8%), followed by orbital (106, 38.3%), temporal artery (17, 6.1%), optic nerve (9, 3.2%), and conjunctival (7, 2.5%) lesions. A review of appropriate indications for intraoperative diagnosis is presented and a description of tissue handling and procedures to obtain better results in ophthalmic pathologic lesion cases is discussed.

Conclusions.—The most frequent indications for frozen sections in ophthalmic abnormalities are for margin control in eyelid and orbital lesions. At my institution, the second most frequent indications for ophthalmic frozen sections are the evaluation of adequacy of tissue sampling and triaging for flow cytometry and molecular techniques, especially in childhood malignancies.

Sebaceous carcinoma of the ocular region: a review

Sebaceous carcinoma of the ocular region is a malignant neoplasm that is being recognized more frequently and managed by innovative techniques of local resection, cryotherapy, topical chemotherapy, and radiotherapy, resulting in improved visual and systemic prognosis.

Sebaceous Carcinoma of the Eyelid: A Review of 14 Cases

BACKGROUND

Sebaceous carcinoma of the eyelid is a rare tumor. Treatment can be complicated by noncontiguous spread of the tumor.

OBJECTIVE

Review a series of patients with sebaceous carcinoma to illustrate clinical presentations, treatments, and outcomes.

METHODS

We retrospectively reviewed medical records of patients with sebaceous carcinoma treated at Mayo Clinic (Rochester, MN).

RESULTS

Fourteen patients had sufficient follow-up data available for review. Mean follow-up was 57 months (range 18-134 months). Treatment included wide local excision with frozen and permanent section control (9 patients, 64%), Mohs micrographic surgery (2 patients, 14%), external beam radiation (2 patients, 14%), and exenteration and total parotidectomy with cervical lymph node dissection (1 patient, 7%). Two patients (14%) had local recurrence of the tumor after wide local excision, and 1 patient (7%) had tumor recurrence after Mohs micrographic surgery.

CONCLUSION

Treatment should be chosen on the basis of the extent of the tumor and the specific needs of the patient. The mainstay of treatment of tumors without orbital involvement has been wide local excision, with the margins checked in both permanent and frozen sections, in combination with conjunctival map biopsies when warranted. Mohs micrographic surgery is an alternative that may provide tissue conservation and lower recurrence rates. Recurrence rates between treatments are difficult to assess because of the small number of cases reported in the literature. In cases with orbital involvement, exenteration may be warranted. Radiation may be useful when surgery cannot be tolerated.

Sebaceous carcinoma and the T-antigen

Carcinomas of sebaceous glands are uncommon. They are traditionally classified into ocular and extraocular sebaceous carcinomas (SC). Ocular SC tend to be more common and more aggressive than extraocular SC. However, the latter can occasionally follow a fatal course. Histologically, SC should be classified into 1) SC in situ; 2) SC, infiltrating, low-grade with or without pagetoid spread; 3) SC, infiltrating, high-grade, with or without pagetoid spread; and 4) SC with extraocular and extracutaneous involvement, including metastases. Immunohistochemistry plays a minor role in the diagnosis of SC. Thomsen-Friedenreich (T) antigen can be a helpful tool in differentiating SC (strong T-antigen reactivity in basaloid cells) from other mimicking neoplasms (basaloid cells are T-antigen negative). The histologic differential diagnosis, pathogenesis, and management of SC are reviewed.

Mohs micrographic surgery of a papillary eccrine adenoma

BACKGROUND

Papillary eccrine adenoma (PEA) is a rare benign sweat gland neoplasm first described by Rulon and Helwig in 1977. Although these lesions typically behave in a benign fashion, PEA's on the volar surfaces may demonstrate more aggressive biologic behavior. Additionally, aggressive digital papillary adenomas (ADPA) may histologically simulate PEAs and behave in a more malignant fashion.

OBJECTIVE

To present a case report of a patient with an incompletely excised PEA that was successfully extirpated using Mohs micrographic surgery (MMS).

METHODS

A 51-year-old black woman was evaluated for the treatment of an incompletely excised PEA located on the dorsum of her left hand at the base of the thumb. Mohs micrographic surgery was felt to be the ideal treatment choice because of incomplete prior resections, ill-defined clinical borders, the need for conservative surgical excision to preserve sensory and motor function of the left hand, and the previously reported more aggressive nature of this tumor when located on volar surfaces. The patient underwent a two-stage, six section micrographically controlled excision using the fresh tissue technique.

RESULTS

Complete resection of the PEA without significant damage to neurovascular structures.

CONCLUSION

This case demonstrates the increasingly important role MMS is playing in the surgical management of a wide variety of cutaneous tumors. To our knowledge, this is the first time MMS has been used in the resection of a PEA.

Sebaceous carcinoma of the eyelids treated by mohs micrographic surgery: report of nine cases with review of the literature

BACKGROUND

Ocular sebaceous carcinoma (SC) is a rare tumor of the eyelids. Clinically it frequently involves the upper lid in older women. Microscopically it tends to extend far beyond its assessed clinical margins. SC is characterized by a variety of tissue invasion mechanisms. It may spread by direct extension, be multifocal in advanced cases, and develop "skip areas" after trauma. Despite its ability to develop discontinuity, over the past two decades there have been several favorable case reports of SC treated by Mohs micrographic surgery (MMS).

OBJECTIVE

To illustrate by case report the clinical presentation and management of patients with SC and to document our series of SC patients treated by MMS over the last 14 years.

METHODS

A retrospective study was conducted of all cases of sebaceous carcinoma involving the ocular adnexa treated at the University of Wisconsin Mohs Surgery Clinic from 1987 to 2001. We also reviewed the accumulated medical literature of SC treated by MMS.

RESULTS

In our series, there were nine cases of periocular SC. Five cases originated on the upper lid and four on the lower lid. Five of nine patients (55%) showed epithelial invasion. One patient developed a local recurrence 1.5 years later and was treated by orbital exenteration. This patient has had no evidence of disease for 5 years. Eight of nine patients (88%) had no evidence of local recurrence with a follow-up of 1-14 years. In our literature review we found 40 additional cases of orbital SC treated by MMS. Intraepithelial spread of SC was found in 50% of patients (24 of 48). Six patients developed local recurrence. The overall local cure rate following MMS is 87.8% (43 of 49), with a mean follow-up of 3.1 years. The regional metastatic rate was 8% (4 of 49). There were no deaths reported.

CONCLUSION

We present nine new cases of SC. The age, sex, and site distribution are compatible with other SC cases reported in the literature. We reviewed the medical literature and compiled 49 cases of SC treated by Mohs surgery. Intraepithelial spread was discovered in 50% of the cases. Multifocal disease or discontinuity was present in 6% (3 of 49). Mohs surgery appears to be an effective method for excising the microscopic ramifications of primary SC. When feasible, we recommend in SC cases where intraepithelial pagetoid spread has been observed, that removal of another Mohs layer should be considered in order to provide an additional assurance layer against local tumor recurrence.