Microcystic adnexal carcinoma: a diagnostic and therapeutic challenge

Microcystic adnexal carcinoma of the eyelid and orbit: A case report and review of literature

Microcystic adnexal carcinoma (MAC), a rare and low-grade malignant skin tumor, is characterized by a high rate of misdiagnosis and a preponderance for local recurrence, but seldom seen nodal or distant metastasis. Although MAC typically occurs almost in the head and neck region, primary eyelid or orbital MAC is very rare. To explore the unique characteristics of the eyelid and orbital MAC, we reviewed the relevant literature. Based on its distinctive anatomical location and the aggressive behavior, eyelid or orbital MAC not only exhibit a high rate of misdiagnosis and local recurrence, but also lead to serious complications such as disfigurement after orbital exenteration, paranasal sinuses or intracranial invasion, even death. Misdiagnosis of MAC commonly result from its rarity and nonspecific clinical and histopathological presentation. To reduce or avoid misdiagnosis, it is important to increase awareness for MAC and obtain a full-thickness biopsy specimen in histopathological analysis. Due to its extensive invasive growth pattern, MAC has a high rate of local recurrence, so complete excision with clear margins and long-term follow-up of patients with MAC are necessary. About those serious complications of the eyelid and orbital MAC, early and accurate diagnosis, complete excision is very important. Moreover, an interprofessional team consisting of ophthalmologist, otolaryngologist, neurologist, dermatologist, pathologist, radiologist is needed to evaluate and treat this disease. In summary, increasing awareness, early and accurate diagnosis, complete excision, long-term follow-up, and a multidisciplinary team is crucial for management of the eyelid and orbital MAC.

Microcystic adnexal carcinoma: report of rare cases

Microcystic adnexal carcinoma (MAC) is a rare, locally aggressive malignant neoplasm that derives from cutaneous eccrine/apocrine glands. MAC is classified as an eccrine/apocrine gland tumor and usually occurs in the skin. Here, we characterized and compared two cases of MAC. One is extremely rare in terms of its occurrence in the tongue. The other occurred in the lip, which is common. Histories of disease, diagnosis, and differentials were reviewed by the attending physicians. Hematoxylin and Eosin (HE) slides were evaluated by an experienced pathologist. Immunological markers for malignant eccrine/apocrine gland tumors were used to characterize the tumor’s nature. The examined markers included EMA, CK5/6, CK8/18, CK7, CK20, p63, S-100, Calponin, CD10, MYB, Bcl-2, Her-2, CD34, SMA, p53, CD43, CD117, and Ki-67. Both patients were males, presented with painless lumps in the lower lip and in the tongue, respectively. Both lumps were similar in terms of appearance, being whitish, and infiltrative with irregular borders. Both tumors also had similar histological features with nests of bland keratinocytes, cords, and ductal differentiation filled with Periodic acid–Schiff (PAS)-positive eosinophilic material. In both cases, circular or ovary tumor cells invaded into muscles and nerves. All tumor cells were CK5/6, CK8/18, EMA, and CK7 positive. Particularly, keratinocytes were p63 positive, and paraductal cells were p63, S-100, and SMA positive. Therefore, the rare case of MAC in the tongue appears to derive from the salivary gland.

An atypical presentation of extensive centrofacial microcystic adnexal carcinoma responding to radiation: A case report and review of the literature

Microcystic adnexal carcinoma is a rare cutaneous neoplasm believed to arise from pluripotent keratinocytes capable of adnexal differentiation. Due to its insidious growth and appearance, diagnosis is often delayed. A deep incisional or excisional biopsy for histopathology is the gold standard for diagnosis. Different treatment modalities have been described in the literature, including the Mohs micrographic surgery, standard excision, radiation, chemotherapy, and observation. Currently, Mohs remains the treatment of choice. We present a unique case of a 12-month history of an extensive progressive centrofacial cutaneous induration diagnosed as microcystic adnexal carcinoma in an 83-year-old female. Due to the extensive nature of the tumor, she received radiation therapy and continues to receive ongoing assessment with no evidence of clinical recurrence at 2-year post-treatment including negative scouting biopsies. To date, there is no consensus on the optimal treatment for microcystic adnexal carcinoma.

Metastatic Basal Cell Carcinoma of the Skin: A Comprehensive Literature Review, Including Advances in Molecular Therapeutics

Basal cell carcinoma (BCC) of the skin is the most common type of malignant human tumor. In Europe, the incidence of BCC ranges from 44.6 to 128 cases per 100,000 inhabitants annually, whereas in the United States, the yearly incidence rate ranges between 500 and 1500. The global incidence has been calculated to be as high as 10 million cases of BCC per year. There are 2 main clinical patterns of BCC-the familial BCC in basal cell nevus syndrome and sporadic BCC. The etiology of cutaneous BCC is usually the result of the interaction between solar ultraviolet radiation and genetic factors. Somatic or germline mutations in the effector components of the hedgehog signaling pathway (ie, PTCH1, PTCH2, SMO or SUFU genes) are responsible for ∼90% of the cases of both sporadic and familial BCC, all causing a constitutive activation of the hedgehog pathway. Cutaneous BCC very rarely metastasizes, and diagnosis in metastatic sites can be very difficult. Metastatic BCC has weakly effective therapeutic options with a poor prognosis until few years ago. In 2012, small-molecule therapies, involving inactivation of the hedgehog signaling pathway, and capable of reducing tumor growth and progression have been introduced into clinical practice for advanced (locally advanced or metastatic) BCC. We performed a comprehensive literature review on metastatic BCC and found at least 915 cases reported to date. In addition, we extensively discussed the differential diagnosis of metastatic BCC, and outlined the advances in clinical therapeutics involving these small molecules.

Metastatic Cutaneous Basal Cell Carcinoma: Report of 2 Cases Preceding the Hedgehog Pathway Antagonists Era

Basal cell carcinoma (BCC) of the skin is the most common type of malignant human tumor. However, metastatic BCC is a very rare event with weakly effective therapeutic options and a poor prognosis, until a few years ago. In 2012, small-molecule therapies, capable of inactivating the hedgehog signaling pathway and thus reducing tumor growth and progression, were introduced into clinical practice for the treatment of patients with advanced BCC. We present retrospectively 2 personal cases of metastatic BCC of the skin, from the premolecular therapy era, from primary tumors that arose years before in the head and neck area. The former case occurred in a 45-year-old woman with a history of recurrent BCC of the retroauricular skin who eventually died due to diffuse metastatic spread. The latter case concerned a 70-year-old man also with a history of recurrent BCC of the nasal-perinasal skin who developed multiple subcutaneous and lymph node metastases in the neck. In both cases, the diagnoses were based on biopsies of the metastatic sites. The first patient died 5 months after the diagnosis of metastatic disease, while the second was alive and disease-free 2 years after neck lymph node dissection and external radiation therapy, and then lost to follow-up. We extensively discuss several tumor entities with basal or basaloid features that may enter the differential diagnosis with BCC in metastatic sites. In addition, we briefly summarize the advances in clinical therapeutics using small molecules, which are now an integral part of the treatment of such advanced BCC cases.

Axillary and elbow lymph node metastasis arising after complete excision of microcystic adnexal carcinoma of a hand: A rare presentation

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MAC arising at a hand may require wider excision in order to achieve best result.

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The metastatic route could be explained the spreading via lymphatic system.

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CT scan renders more details and more precise diagnosis in a suspicious situation.

Introduction

Microcystic adnexal carcinoma (MAC), a malignant transformation of adnexal structures, constitutes a rare locally aggressive malignancy of skin. Generally, the disease is associated with local invasion and distant metastases are extremely rare. We presented a case of MAC with distant metastasis after adequate wide excision.

Presentation of case

A 65-year-old man presented with a scar-like lesion at his left hand’s middle finger. As pathologic result from incisional biopsy confirmed MAC, the patient was then treated with ray amputation. Eight years later, there was a presence of scar changes. There was a palpable node at medial epicondyle and presence of enlarged lymph nodes at axilla by imaging with Computed tomography (CT) scan. Following left hand amputation and node dissection at elbow and axillary region, pathologic examination confirmed recurrence and metastasis of MAC. He went through adjuvant radiation with a complete response. At present, two years after surgery, he remains in complete remission.

Discussion

The presence of a recurrent MAC with distant lymph node metastasis after primary surgery is rare. The metastatic route as presented with the positive nodes at elbow and axilla could be explained the spreading via lymphatic system.

Conclusion

MAC arising at a hand may require wider excision in order to achieve best result. Although this malignancy is a slowly progressive disease, distant metastasis should always be concerned, especially when there are suspicious presentations. CT scan will render more details and make more precise diagnosis in the suspicious situation.

Microcystic Adnexal Carcinoma and a Summary of Other Rare Malignant Adnexal Tumours

OPINION STATEMENT

Microcystic adnexal carcinoma (MAC) is a rare, slow-growing, infiltrative malignant tumour most commonly found on the head and neck. It often presents as a solitary skin-coloured or yellow papule, plaque or nodule. Ultraviolet radiation, immunosuppression and ionising radiation are possible risk factors. Clinical and histological differential diagnoses include morpheaform basal cell carcinoma and desmoplastic trichoepithelioma. The diagnosis is usually made by skin biopsy, and the characteristic features are small keratin-filled cysts with nests and cords which resemble ductal structures. Immunohistochemistry can assist in differentiating MAC from other tumours. The local aggressive nature of the tumour and its potential to infiltrate beyond the assessed clinical margins warrant complete excision with marginal control, and we recommend Mohs micrographic surgery. Wide local excision is widely performed but is associated with recurrence given its infiltrative nature and extensive subclinical extension. The role of radiotherapy in the management of MAC is unclear.

Histologic Mimics of Basal Cell Carcinoma

CONTEXT

- Basal cell carcinoma (BCC) is the most common human malignant neoplasm and is a frequently encountered diagnosis in dermatopathology. Although BCC may be locally destructive, it rarely metastasizes. Many diagnostic entities display morphologic and immunophenotypic overlap with BCC, including nonneoplastic processes, such as follicular induction over dermatofibroma; benign follicular tumors, such as trichoblastoma, trichoepithelioma, or basaloid follicular hamartoma; and malignant tumors, such as sebaceous carcinoma or Merkel cell carcinoma. Thus, misdiagnosis has significant potential to result in overtreatment or undertreatment.

OBJECTIVE

- To review key features distinguishing BCC from histologic mimics, including current evidence regarding immunohistochemical markers useful for that distinction.

DATA SOURCES

- Review of pertinent literature on BCC immunohistochemistry and differential diagnosis.

CONCLUSIONS

- In most cases, BCC can be reliably diagnosed by histopathologic features. Immunohistochemistry may provide useful ancillary data in certain cases. Awareness of potential mimics is critical to avoid misdiagnosis and resulting inappropriate management.

Treatment of Malignant Cutaneous Adnexal Neoplasms

Malignant cutaneous adnexal neoplasms form a group of rare, typically low-grade-malignancy carcinomas with follicular, sebaceous, apocrine, or eccrine differentiation or a combination of the first 3 subtypes. Their clinical presentation is usually unremarkable, and biopsy is required to establish the differentiation subtype and the definitive diagnosis. Due to their rarity, no clear consensus has been reached on which treatment is most effective. Mohs micrographic surgery is considered to be the best option to prevent recurrence in the majority of patients. Radiotherapy and chemotherapy have been studied in very few cases and have rarely been shown to be effective.

Surgery and Adjuvant Radiation for High-risk Skin Adnexal Carcinoma of the Head and Neck

OBJECTIVES

Skin adnexal carcinoma (SAC) is a rare cutaneous malignancy that arises from sebaceous and sweat glands. These carcinomas are believed to behave more aggressively than cutaneous squamous cell carcinomas (SCC) with a propensity for local recurrence. The role of adjuvant radiotherapy in SAC is undefined.

METHODS

We retrospectively reviewed all cases of head and neck SAC treated with surgery and adjuvant radiation from 2000 to 2012 at a single institution.

RESULTS

Nine cases were identified. Median age was 67 (range, 52 to 88) years. The histologies were: adnexal carcinoma (n=1), adnexal carcinoma with sebaceous differentiation (n=1), adnexal carcinoma with squamous differentiation (n=1), skin appendage carcinoma (n=1), sclerosing sweat duct carcinoma (n=1), mucinous carcinoma (n=1), ductal eccrine adenocarcinoma (n=1), porocarcinoma (n=1), and trichilemmal carcinoma (n=1). All tumors were reviewed by a dermatopathologist to confirm the SAC diagnosis.All patients had undergone surgery. Indications for adjuvant radiation included involved lymph nodes (n=4), perineural invasion (n=2), nodal extracapsular extension (n=2), positive margin (n=1), high-grade histology (n=6), multifocal disease (n=2), and/or recurrent disease (n=5). Radiation was delivered to the primary site alone (n=3), to the draining lymphatics alone (n=2), or to both (n=4). One patient received concurrent cisplatin. Median dose to the primary site was 60 Gy and to the neck was 50 Gy.Median follow-up was 4.0 years (range, 0.6 to 11.4 y). Locoregional control was 100%. Five-year progression-free survival was 89%. There was 1 acute grade 3 toxicity and no greater than or equal to grade 2 late toxicities were recorded.

CONCLUSIONS

Surgery and adjuvant radiation for high-risk SAC offers excellent locoregional control with acceptable toxicity.

Incidence and Clinical Features of Rare Cutaneous Malignancies in Olmsted County, Minnesota, 2000 to 2010

BACKGROUND

The incidence of rare cutaneous malignancies is unknown. Current estimates of rare cutaneous malignancy incidences are based on broad epidemiologic data or single institution experiences, not population-based data.

OBJECTIVE

To determine the incidence of several rare nonmelanoma skin cancers.

MATERIALS AND METHODS

The authors conducted a retrospective chart review of a population-based cohort between the years 2000 and 2010. Residents of Olmsted County, Minnesota, who were diagnosed with a biopsy-proven nonmelanoma skin cancer-excluding basal cell carcinoma and squamous cell carcinoma-were included in this study. The primary outcome was tumor incidence. Additionally, the authors extracted patient demographics, tumor characteristics, treatment modalities, and outcomes.

RESULTS

The age-adjusted and sex-adjusted incidences per 100,000 persons of multiple rare cutaneous malignancies were: atypical fibroxanthoma (1.8), sebaceous carcinoma (0.8), dermatofibrosarcoma protuberans (0.4), microcystic adnexal carcinoma (0.7), eccrine carcinoma (0.4), eccrine porocarcinoma (0.2), and leiomyosarcoma (0.2).

CONCLUSION

The authors report population-based incidences and clinical characteristics for these rare cutaneous malignancies. The immune status and smoking status of patients and the treatment and outcomes of these tumors are reported. Additional studies in a broader population are needed to further define the epidemiology and outcomes of these malignancies.

Microcystic Adnexal Carcinoma of the Nasal Tip Treated With Surgical Excision and Rotational Forehead Skin Flap

Microcystic adnexal carcinoma (MAC) is a rare malignant cutaneous adenocarcinoma that typically occurs in the head and neck, particularly at the central face. There are only slightly more than 300 patients reported worldwide, and most patients occur in Caucasians. A 72-year-old man was referred to our hospital for definitive treatment of known MAC from previous biopsy. Wide excision of nasal tip and reconstruction of nasal defect with paramedian forehead flap and nasolabial flap transposition were performed rather than conventional Mohs surgery, due to grossly evident disease. Pathological examination verified 4.5 × 3 cm sized MAC with free resection margins. The patient is being followed up without any evidence of disease.

Microcystic adnexal carcinoma in a non-Caucasian patient: A case report and review of the literature

Microcystic adnexal carcinoma (MAC) is extremely rare among Asians, with the majority of cases presenting in Caucasian individuals. The current study describes the case of a 38-year-old Chinese woman who presented with a 10 year history of a mass in the upper lip. A biopsy resulted in a diagnosis of MAC. The patient underwent complete surgical resection and the tumor was successfully excised. During 6 months of follow-up, there was no evidence of recurrence. To the best of our knowledge, the present case is the first Chinese case to be reported in the English literature, and is presented with the aim of increasing the awareness and aiding in the management of MAC in non-Caucasian populations.

Misdiagnosed microcystic adnexal carcinoma on the lateral forehead and challenges in reconstruction of a large and bone-deep defect

BACKGROUND

Microcystic adnexal carcinoma (MAC) is a rare cutaneous malignancy characterized by aggressive local infiltration, including a high propensity for perineural invasion. Histologically it can be easily confused with benign adnexal tumors, which often leads to inappropriate initial treatment. As a consequence delayed surgical excision often requires removal of large cutaneous masses which can be followed by challenges in reconstruction.

METHODS

We report the case of a challenging reconstruction of a large forehead defect by a modified AT flap with central Burow's triangle grafting and previous wound conditioning using hyaluronic acid after complete micrographic removal of MAC.

RESULTS

A 80-year-old healthy female presented with an almost six year history of an asymptomatic slowly progressing skin mass previously biopsied and diagnosed as benign syringoma five years in advance. Deep biopsies confirmed MAC. She underwent staged surgical excision with Tübingen torte technique with removal of the frontal periostium. A skin substitute of esterified hyaluronic acid was applied for three weeks to the bone-deep 6 × 7 cm defect leading to good granulation tissue above the bone. Final reconstruction was achieved by an AT flap combined with full thickness skin transplantation of the central dog ear. The cosmetic outcome was satisfactory, no recurrence was observed within 18 months follow-up.

CONCLUSIONS

We confirm the histological difficulties in the diagnosis of this tumor entity and the large extension of MAC due to delay in diagnosis and treatment. Deep tumor removal including the periostium might be necessary to achieve tumor free margins. Fast granulation tissue above the frontal bone might be achieved by applying hyaluronic acid products. The combination an AT flap with transplantation of the adjacent Burow's triangles gives optimal skin texture and color matching and seems to be a good option to close even large defects of the front especially for supra brow defects.

Challenges in the diagnosis of cutaneous adnexal tumours

The diagnosis of cutaneous adnexal neoplasms, a heterogeneous group of entities, is often perceived by practising pathologists as challenging. A systematic approach to diagnosis is necessary for classification of these lesions, which establishes the tumour differentiation (follicular, sebaceous, sweat gland or apocrine) and evaluates histological features differentiating between benign and malignant entities. Consideration of clinical history is a necessary adjunct in evaluation of the adnexal neoplasm, as characteristic anatomical sites are described for many adnexal lesions. In some instances, immunohistochemical studies may also be employed to aid the diagnosis. The differential diagnosis between primary cutaneous adnexal neoplasms and cutaneous metastases from visceral tumours may also be difficult. Clinical, radiological, histological and immunohistochemical characteristics will be further discussed, considering that the correct diagnosis has a significant impact on the patient's management and prognosis.

Longtime undetected microcystic adnexal carcinoma of the scalp: considerations and implications

BACKGROUND

Microcystic adnexal carcinomas (MACs) are slow-growing and often asymptomatic malignant skin tumours that usually develop on the facial skin and may reach considerable size. We present an uncommon case of MAC arising on the hair-bearing scalp and discuss our experiences and considerations.

CASE REPORT

A 58-year-old female was admitted with a histopathologically secured diagnosis of MAC of the temporal and occipital regions that had expanded to 10 × 12 cm. Magnetic resonance imaging revealed an infiltration of the skin and the subcutaneous adipose tissue. No lymphatic or haematogenic metastases were detected. Therapy consisted of resecting the tumour and reconstructing the area by applying an anterolateral thigh (ALT) flap. Histopathological evaluation revealed clear, 1-cm margins and a tumour-free periosteum. One-year postoperative follow-ups showed no evidence of recurrence, while the outcome was aesthetically pleasing.

CONCLUSION

When screening for skin cancer, careful attention must be paid to the scalp. Resection of MAC with clear margins is mandatory to minimize the risk of recurrence. In this case, applying an ALT perforator flap to a large defect of the hair-bearing scalp led to a very satisfying result; it should be considered in comparable cases.

Treatment of nasal microcystic adnexal carcinoma with an expanded rotational forehead skin flap: A case report and review of the literature

Microcystic adnexal carcinoma (MAC) is a rare and locally aggressive adenocarcinoma with low-grade malignancy. The present study describes the first reported case and treatment of a Chinese male with a MAC located on the nasal dorsum and nosewing. A 44-year-old man presented with a nasal deformity caused by local repeated infections following an accidental injury to the nose 20 years previously. The nose had been injured by a brick, and treatment at a local hospital 12 years previously had resulted in a nasal scar and a gradually enlarging mass. A physical examination revealed a hypertrophic deformity of the nose and an indurated scar plaque, measuring 2.0×2.0 cm, on the nasal dorsum and nosewing. Microscopic examination revealed a tumor consisting of solid cell nests and a cystic structure with a capsular space. In addition, ductal cells of an adnexal cell origin were visible in the outer epithelium. The medial portion exhibited a microductal structure and invasion of deeper tissues without evident atypia. The tumor cells presented normal nuclear to cytoplasmic ratios and minimal mitotic activity. Pathological examination verified that the tumor was a MAC of low-grade malignancy. A complete surgical resection was performed via Mohs micrographic surgery (MMS), and reconstruction was achieved using an expanded rotational forehead skin flap. No tumor recurrence was detected after a three-year follow-up period. Therefore, for effective treatment of similar MAC cases, complete surgical resection using MMS is recommended, and successful reconstruction may be achieved using an expanded skin flap.

Malignant cutaneous adnexal tumours of the head and neck: an update on management

Adnexal tumours form a heterogeneous group of relatively rare neoplasms. Many of them have a poor prognosis and treatment can sometimes be difficult and controversial. We summarise the latest publications relating to malignant cutaneous adnexal tumours of the head and neck, and give an update on their management. We discuss Merkel cell carcinoma and other rare malignant adnexal tumours including dermatofibrosarcoma protuberans and atypical fibroxanthoma.

Benign subclinical syringomatous proliferations adjacent to a microcystic adnexal carcinoma: a tumor mimic with significant patient implications

Microcystic adnexal carcinoma (MAC) is an uncommon, locally aggressive, malignant cutaneous tumor with pilar and eccrine differentiation. Mohs micrographic surgery is the treatment of choice for this condition, but specific histological findings can complicate MAC removal and leave doubt as to whether the tumor has been completely removed. Here we describe the clinical and pathological characteristics of a case in which a patient with an MAC underwent multiple reexcisions because of the presence of benign subclinical syringomatous proliferations adjacent to the primary lesion. Our case raises awareness of syringomatous proliferation, a benign process histologically similar but behaviorally distinct from a primary MAC. This experience highlights the importance of continued communication between dermatopathologists and dermatologic surgeons in providing quality patient care.

Correlation of optical coherence tomography and histology in microcystic adnexal carcinoma: a case report

BACKGROUND/AIMS

Herein, we report a case of microcystic adnexal carcinoma (MAC), which we correlated and evaluated by optical coherence tomography (OCT) and conventional H&E histology.

METHODS

A commercially available OCT scanner was used for imaging. Several multi-slice images were obtained from the central portion of the lesion. Correlation of OCT findings with histology was performed retrospectively.

RESULTS

Microcystic adnexal carcinoma showed characteristic criteria, which were divided into superficial and sub-epidermal findings.

CONCLUSION

The use of OCT can visualize characteristic criteria of MAC, thus enabling prompt diagnosis before surgery.

Prevalence of human polyomaviruses in common and rare types of non-Merkel cell carcinoma skin cancer

BACKGROUND

Little is known about the association of human polyomaviruses (HPyVs) other than Merkel cell polyomavirus (MCPyV) with nonmelanoma skin cancer.

OBJECTIVES

To evaluate the presence of HPyV6, HPyV7, trichodysplasia spinulosa-associated polyomavirus (TSV), also called HPyV8, and the recently discovered HPyV9 in basal cell carcinoma (BCC), actinic keratosis (AK), squamous cell carcinoma in situ (SCCis), squamous cell carcinoma (SCC), keratoacanthoma (KA), microcystic adnexal carcinoma (MAC) and atypical fibroxanthoma (AFX).

METHODS

Archival paraffin-embedded samples (n = 193: 41 BCC, 31 AK, 8 SCCis, 52 SCC, 42 KA, 5 MAC and 14 AFX) were analysed for the presence of the respective HPyV by polymerase chain reaction (PCR). HPyV DNA loads (HPyV DNA copies per β-globin gene copy) were determined in all HPyV-positive samples by quantitative real-time PCR. Immunohistochemical analysis of MCPyV large T-antigen (LTA) expression was performed using the monoclonal antibody CM2B4.

RESULTS

MCPyV DNA was found in 29% of BCC, 19% of AK, 25% of SCCis, 27% of SCC, 29% of KA, 0% of MAC and 29% of AFX. MCPyV DNA loads never exceeded 0·3 MCPyV DNA copies per β-globin gene copy (median 0·004). In the immunohistochemical analysis of MCPyV LTA expression, all evaluated samples (32 MCPyV DNA-positive samples) were LTA negative. HPyV6 DNA was found in 7% of BCC, 3% of AK, 12% of SCCis, 4% of SCC, 5% of KA, and 0% of MAC and AFX. HPyV6 DNA loads never exceeded 0·7 HPyV6 DNA copies per β-globin gene copy (median 0·015). None of the 193 samples was positive for HPyV7, TSV or HPyV9 DNA.

CONCLUSIONS

Our findings argue against a pathogenic role for MCPyV, HPyV6, HPyV7, TSV and HPyV9 in the analysed types of non-Merkel cell carcinoma skin cancer.

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.

Microcystic adnexal carcinoma of the skin: the role of adjuvant radiotherapy

INTRODUCTION

Microcystic adnexal carcinoma (MAC) is a rare cutaneous tumour where the role of radiotherapy remains undefined. We contrast our institutional experience with current literature, define the local control rate and suggest a role for adjuvant radiotherapy in the treatment of this cancer.

METHODS

From 1992-2008, a retrospective review was undertaken for MAC treated with curative intent involving surgery and adjuvant radiotherapy at the Royal Brisbane Hospital and Mater Hospital Brisbane. Clinical, pathologic and treatment details as well as patterns of recurrence were analysed.

RESULTS

Fourteen cases of MAC received local excision and adjuvant radiotherapy. The median age was 71 years old, with nine of the cases in men. All cases occurred in the head and neck region with mean tumour size of 20.5 mm and mean depth of invasion of 9.9 mm. Peri-neural invasion occurred in 56% of cases and 69% had positive surgical margins. Various adjuvant radiotherapy schedules were used to treat the primary site resulting in a crude local control rate of 93%. Primary and nodal relapses were subsequently salvaged with further treatment.

CONCLUSION

While Mohs micrographic surgery may be considered the gold standard, wide local excision and adjuvant radiotherapy offers comparable control rates. Doses of 50 Gy or greater should be prescribed with generous margins (3-5 cm) owing to its tendency for peri-neural and deep invasion. There was no evidence that radiotherapy can cause aggressive transformation of the tumour. The role for definitive radiotherapy remains uncertain.

Microcystic adnexal carcinoma: the first reported congenital case

Microcystic adenexal carcinoma is a rare, locally aggressive, malignant appendage tumor also known as sclerosing sweat duct carcinoma. Since widespread recognition of microcystic adenexal carcinoma as a distinct clinicopathologic entity, approximately 300 total cases have been reported in the literature, with only eight previous cases reported in children under the age of 18, with no reported cases in patients younger than 6 years old. Our patient is unique in that the lesion was present at birth, making this the youngest case of microcystic adenexal carcinoma reported.

Microcystic adnexal carcinoma - aggressive infiltrative tumor often with innocent clinical appearance

Microcystic adnexal carcinoma is a rare sweat gland malignancy, characterized by slow, but aggressive infiltrative growth. Histologic characteristics are follicular and glandular differentiation, as well as bland cytologic features. The benign histologic appearance, particularly in the upper level of the tumor, can be confused with syringoma or benign follicular neoplasm. Thus the risk of misdiagnosis is considerable, especially if only superficial biopsies are provided. We report two patients with microcystic adnexal carcinoma, using them as a basis to discuss, pathogenesis, diagnosis, histology and therapy of the tumor.

Supraorbital neuroma masquerading as local recurrence from a previously excised microcystic adnexal carcinoma

We present a case of a 53 year old gentleman with a previous history of a microcystic adnexal carcinoma in the supraorbital region who represented with pain and tenderness 3 years postoperatively. Although this was thought to represent local recurrence, it proved to be a supraorbital neuroma.