Primary mucinous carcinoma of the skin: a population-based study

Primary cutaneous mucinous carcinoma of the cheek: a case report

BACKGROUND

Primary cutaneous mucinous carcinoma is a rare neoplasia of the sweat gland. The age-adjusted incidence was 0.024 tumors per 100,000 person-years. It is possible that the actual number of tumors may be slightly higher than previously estimated as some cases of primary cutaneous mucinous carcinoma may have been mistaken for benign tumors and removed by laser therapy without histologic examination.

CASE PRESENTATION

We report a 58-year-old Chinese man with primary cutaneous mucinous carcinoma. The patient presented to our care with an indolent nodule on the left cheek, which was proven to be a mucinous adenocarcinoma by excisional biopsy and immunohistochemical staining. Following a comprehensive evaluation, including whole-body computed tomography and positron emission tomography, metastases from other sites were ruled out and the patient was diagnosed with primary cutaneous mucinous carcinoma. The patient underwent an additional wide resection surgery to ensure a safe margin and was then recommended to undergo regular follow-up.

CONCLUSION

This case is one of the few published Chinese cases in literature of primary cutaneous mucinous carcinoma. Diagnosis of primary cutaneous mucinous carcinoma is challenging, and treatment options are limited. Collaboration between clinicians and pathologists is crucial for optimal outcomes. Further studies with longer follow-up periods are necessary to provide evidence for the management of this disease.

Primary Mucinous Carcinoma of Skin: A Rare Cutaneous Neoplasm. Clinicopathologic Features, Differential Diagnoses, and Review of Literature

ABSTRACT

Primary mucinous carcinoma of the skin (PMCS) is a rare malignant neoplasm of sweat gland origin, with an incidence of 0.07 per million. Histologically, it may be difficult to differentiate it from metastatic mucinous carcinomas of the skin. A case of PMCS is reported here in a 59-year-old woman who presented with a lesion on the right lower eyelid. Histological examination revealed features of mucinous adenocarcinoma. The main differential diagnosis was metastatic mucinous adenocarcinoma; however, the lack of colorectal and lung markers and the presence of focal in situ components were consistent with the diagnosis of PMCS. PMCS and breast mucinous carcinoma share immunohistochemical markers, such as GCDFP-15 and mammaglobin; however, focal in situ component with the presence of myoepithelial cells in the tumor ruled out metastatic mucinous carcinoma of breast origin. The subsequent mammograms did not reveal any breast lesions. Colonoscopy did not show any evidence of colonic malignancy, and imaging studies (CT scan) did not show any evidence of neoplasm in the body. These findings were in keeping with a diagnosis of PMCS. The present case emphasizes the importance of clinicopathological correlation, histopathology, and immunohistochemistry in the accurate diagnosis of PMCS and summarizes the literature on these rare cutaneous neoplasms.

Primary cutaneous mucinous carcinoma of the scalp masquerading as a benign dermatological mass - A case report

INTRODUCTION AND IMPORTANCE

Primary cutaneous mucinous carcinoma (PCMC) is a rare low-grade malignant neoplasm derived from the sweat glands. Local recurrence of PCMC occurs frequently, but these lesions rarely metastasize. Due to the absence of classical demographic and clinical characteristics, PCMCs masquerade as sebaceous cyst, lipoma, pilomatrixoma, chalazion, or squamous cell carcinoma. This misdiagnosis frequently leads to incomplete surgical excision which necessitates further surgical therapy for a curative intent.

CASE PRESENTATION

We present a case of PCMC in a 45-year-old woman which presented as a slow- growing and symptomless nodule in the scalp. After clinical evaluation, the patient had a typical surgical excision for a benign-looking lesion. Histological evaluation of the specimen confirmed a localized PCMC in the scalp with involved surgical margins.

CLINICAL DISCUSSION

A thorough oncological assessment by PET-CT scan and radionuclide scintigraphy was performed. Later, a wide local excision using a gamma probe for intra-operative radionuclide localization of the tumor area and sentinel lymph nodes was done.

CONCLUSION

The patient did not have any regional or distant metastases and remained stable at the time of reporting this case.

Young Man With Primary Mucinous Cell Carcinoma of the Eyelid: 36 Month Follow Up

Primary cutaneous mucinous carcinoma (PCMC) is a malignant adnexal tumor that masquerades as a benign periocular lesion. We present a case of a 29-year-old male with an eyelid PCMC misdiagnosed as a chalazion. He underwent Mohs microscopic surgery for definitive treatment, with no recurrence at his 36 month follow up. Given the rarity and poorer prognosis in younger patients, a high index of suspicion is crucial for biopsying periocular lesions that fail conservative therapy.

Primary Cutaneous Mucinous Carcinoma: A Review of the Literature

BACKGROUND

Primary cutaneous mucinous carcinoma (PCMC) is an exceedingly rare, low-grade tumor that histologically resembles mucinous carcinoma from other primary sites, such as the breast, gastrointestinal tract, and lungs.

OBJECTIVE

The purpose of this article was to review the current literature on PCMC as it relates to epidemiology, clinical presentation, histopathology, immunohistochemistry, treatment, and prognosis.

MATERIALS AND METHODS

An extensive literature review was conducted using PubMed and Ovid MEDLINE to identify articles related to PCMC.

RESULTS

Several hundred cases have been reported in the medical literature, and surgical resection, whenever feasible, is the standard of care.

CONCLUSION

The diagnosis of primary cutaneous mucinous carcinoma is one of exclusion, requiring a metastatic work-up to rule out distant primary. Mohs micrographic surgery is a tissue sparing technique that allows complete margin control of these rare neoplasia.

A Reddish Nodule on the Scalp: A Quiz

Abstract is missing (Quiz)

Recurrent Neuroendocrine Primary Cutaneous Mucinous Carcinoma of the Scalp After Complete Excision

ABSTRACT

Primary cutaneous mucinous carcinoma is a rare, indolent malignancy with a debated history regarding cell of origin. Recurrence is rare but has been documented in up to a third of cases. Recent literature reviews have recognized 2 possible subtypes-neuroendocrine and nonneuroendocrine- with different possible prognostic implications for patients. We describe a case of recurrent primary cutaneous mucinous carcinoma in a 50-year-old man with subtle neuroendocrine features not initially recognized on routine H&E staining but highlighted by immunohistochemical studies. We underscore the importance of immunohistochemical use in these rare cases and emphasize that awareness of these neuroendocrine and nonneuroendocrine subtypes is essential for a complete diagnosis.

A Rare Case of Primary Adenocarcinoma of the Eyelid: Case Presentation and Review of Literature

Primary mucinous adenocarcinoma (PMA) of the eyelid is a very rare malignancy with an incidence of 0.07 per million. Most cases are elderly males with an indolent course of local growth over months. We report a rare case of a 61-year-old gentleman with an aggressive course of PMA. The patient presented with a painless lower right eyelid swelling that developed over a four-month period. Incisional biopsy of the mass disclosed mucinous adenocarcinoma, positive for cytokeratin (CK)7 but negative for thyroid transcription factor 1, S100, and CK20 expression. Magnetic resonance imaging of the orbits revealed an enhancing infiltrative mass extending from the right lower eyelid to the medial canthus and posteriorly into the orbit, the right ethmoid sinuses, and extraconal fat within the orbit. Workup for metastatic disease including scans of chest, abdomen, and pelvis as well as positron emission tomography/computed tomography were negative for other masses. The patient underwent extensive surgery that included exenteration of the right orbit and cervical lymph node dissection followed by adjuvant radiation therapy and chemotherapy due to the extent of periorbital tumor invasion of contiguous tissues. Diagnosis of PMA is a clinical challenge, and immunohistochemistry is essential for diagnosis. To confirm it as a primary tumor, exclusion of metastasis from elsewhere is appropriate. Reported treatment modalities include Mohs micrographic surgery or excision with frozen section and safety margin. Exenteration of the orbit may be indicated depending on the extent of orbital invasion by the tumor. There is limited evidence to guide treatment and follow-up, with information consisting mostly of published case reports and case series.

Primary mucinous adenocarcinoma of the eyelid: A case with initial clinical misdiagnosis requiring surgical re-excision of the tumor

Introduction and importance

Primary mucinous adenocarcinoma (PMA) of the skin is a rare condition that is usually seen in elderly patients, most commonly involves the periorbital region as a slow growing mass. Histopathological and immunohistochemical (IHC) stains are of paramount importance for the diagnosis of these lesions, which are usually misdiagnosed either as benign or metastatic mucinous adenocarcinomas.

Case presentation

We herein report a rare presentation of PMA in a 70-year-old male patient who presented with an upper eyelid residual lesion after being incompletely excised elsewhere as an epidermal cyst and was successfully managed by complete surgical excision with frozen section control of the margins and no evidence of recurrence.

Discussion

PMA is a rare sweat gland malignancy that involves the eyelid in 41.9% in the head and neck area and is a disease of the elderly with median age of 60 years and variable reported racial and gender predilection. Diagnosis of PMA is challenging both clinically and histopathologically, which was the case in our patient's initial incomplete excision with the presumed diagnosis of a benign epidermal cyst. Proper final tissue diagnosis and surgical management in our patient ensured his favorable outcome.

Conclusion

Accurate diagnosis of PMA requires a high index of clinical suspicion and accurate histopathological diagnosis aided by proper IHC markers.

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Primary mucinous adenocarcinoma (PMA) is a rare cutaneous sweat gland malignancy.

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A 70-year-old male with eyelid PMA was misdiagnosed clinically elsewhere as an epidermal cyst.

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He underwent surgical re-excision of the tumor with frozen section control of margins.

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The diagnosis of PMA is challenging, and proper surgical complete excision is necessary.

Prognostic Factors, Treatment, and Survival in Primary Cutaneous Mucinous Carcinoma: A SEER Database Analysis

BACKGROUND

Limited information exists on the demographics, tumor characteristics, and treatment in primary cutaneous mucinous carcinoma (PCMC).

OBJECTIVE

The authors sought to describe prognostic factors, incidence rates, and the subsequent primary malignancy (SPM) risk in patients with PCMC.

METHODS

Primary cutaneous mucinous carcinoma cases in the National Cancer Institute's Surveillance, Epidemiology, and End Results data (1972-2013) were analyzed to provide demographic, cancer-related, and treatment information and to calculate incidence and mortality. Patients were stratified by stage (local, regional, distant disease) for comparison. The risk of developing an SPM was calculated.

RESULTS

Four hundred eleven PCMC cases were identified. The age-adjusted incidence was 0.04 cases per 100,000-person years. Blacks were disproportionately affected by PCMC (0.048; 95% confidence interval, 0.034-0.065; p < .001). Approximately 67.4% of patients had local disease, 10.5% had regional disease, and 5.8% had distant disease. Primary cutaneous mucinous carcinoma-specific mortality was independent of sex, age, race, primary site, histologic tumor grade, tumor size, tumor stage, or treatment. The overall frequency of developing a second primary malignancy was not increased in patients with PCMC.

CONCLUSION

Although PCMC occurs with equally in both sexes, it may be more common in African Americans than previously recognized. Although eyelid PCMC may have a higher rate of distant metastasis, all patients need close follow-up.

Granuloma Annulare - A Manifestation of Primary Cutaneous Mucinous Carcinoma?

The objective of this report is to present a rare case of primary cutaneous mucinous carcinoma (PCMC) manifesting with granuloma annulare (GA), and to discuss the association as a paraneoplastic phenomenon. A 65-year-old female presented with a painless, slow-growing, cystic nodule less than 1 cm over the left lateral canthus. The clinical presentation was highly suspicious of sebaceous cyst. The histopathologic examination revealed variable sizes of neoplastic cell clusters in a pool of abundant mucin. A focus of palisading lympho-histiocytic infiltrate surrounding a necrobiosis suggestive of granuloma annulare adjacent to the tumor is identified. Series of extensive investigations performed did not reveal any primary origin. GA can rarely be associated with various malignant conditions. Its association and prognostic importance to these conditions are unclear. The presence with certain malignancies and the resolution of GA with the treatment of underlying malignancy are an indicator that this condition can very well be a paraneoplastic phenomenon.

Rare Signet Ring Cell Adenocarcinoma of the Colon Metastasis to the Orbit

Metastases arising from primary tumors of the gastrointestinal tract are not commonly encountered in the orbit. Colorectal carcinomas are subcategorized based on morphological and genetic characteristics with these distinctions bearing therapeutic and prognostic significance. The behavior of these subcategories, including their propensity for orbital metastasis, differs, and clinicians treating these tumors must be aware of their metastatic profiles. This report describes a 51-year-old female with right upper lid swelling and ptosis ultimately found, what we believe to be, the first reported case of signet ring cell colon carcinoma metastasizing to the levator muscle and superior orbit. This case serves as a reminder to all clinicians to consider orbital metastasis even in malignancies not typically found in this location.

Primary cutaneous mucinous carcinoma of the scrotum: A rare tumor at a rare site - A case report and review of literature

Primary cutaneous mucinous carcinoma (PCMC) is a rare malignant adnexal tumor of eccrine origin with a higher incidence in the head and neck region of the body while scrotal skin involvement is rare. We report a case of a 72-year-old man with ulceration of painless scrotal lesions of 10 years' duration. Histology of the wedge biopsies of the lesions was mucinous carcinoma. Clinical workup excluded noncutaneous primary sites of mucinous carcinoma and distant metastasis. He had wide excision of the scrotal skin lesions with histological findings of nests of malignant cells separated from pool of mucin by fibrocollagenous septae. Periodic acid–Schiff stain was positive; however, immunohistochemical stains for estrogen and progesterone receptors were negative. No local recurrence was observed after 12 months of follow-up. Scrotal PCMC is a rare tumor; this may probably be the first reported case of this tumor in the scrotum. Prognosis was good following surgical excision.

Prognostic factors and survival outcomes for head and neck cutaneous adnexal cancers

OBJECTIVES

Malignant cutaneous adnexal tumors (MCAT) are rare and comprise a heterogeneous group of cancers. There have been several studies reviewing prognostic factors of these tumors, but no studies focusing on the head and neck. This study aimed to review a large population based database to evaluate prognostic factors that could impact survival.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify patients with MCAT of the head and neck. Both overall and disease specific survival were the main outcome measures for the study. Univariate and multivariate analyses were performed to evaluate the association of suspected prognostic factors with survival.

RESULTS

The five-year OS and DSS were 72.6 and 95.5%, respectively. A favorable factor for OS was surgical resection ([HR] 0.324; P = 0.001), while unfavorable factors for OS include older age (1.051; P < 0.001), higher tumor grade (1.254; P = 0.049), larger tumor size (1.293; P = 0.003), and positive nodal involvement (3.323; P = 0.002). A favorable factor for DSS was surgical resection (0.026; P < 0.001). Unfavorable factors for DSS include older age (1.058; P = 0.046), larger tumor size (2.528; 1.565-4.085; P < 0.001), and positive nodal involvement (4.761; P = 0.022).

CONCLUSION

Review of the SEER database shows good 5-year OS and DSS rates, similar to those cited in other studies. We identified several prognostic factors associated with survival, while histologic sub-type does not seem to be associated with survival. Surgical resection is the mainstay of treatment.

Expression of hormone receptors, adipophilin, and GCDFP-15 in mucinous carcinoma of the skin

BACKGROUND

Primary cutaneous mucinous carcinoma (PCMC) is a rare epithelial tumor with unclear histogenesis.

METHODS

We evaluated the immunohistochemical expression of the estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR) in six cases of PCMC. The immunoreactivity of adipophilin and gross cystic disease fluid protein (GCDFP)-15 was investigated to determine the origin of the tumor.

RESULTS

The study included five males and one female aged 50 to 69 years who presented with a cutaneous mass in the face. Immunoreactivity for ER, PR, and AR was observed in all cases, and all cases were negative for adipophilin but positive for GCDFP-15.

CONCLUSIONS

This report is the first to show AR expression in PCMC. All of followed cases manifested indolent clinical course, and the prognostic significance of hormone receptors in PCMC remains unclear. The negative immunoreactivity of PCMC for adipophilin and positivity for GCDFP-15 suggests a more likely relationship to apocrine than to sebaceous glands.

Mucinous Adenocarcinoma of the Scalp: Primary Cutaneous Neoplasm Versus Underlying Metastatic Disease

Primary cutaneous mucinous carcinoma (PCMC) is a rare mucin-producing malignancy derived from epithelial glandular structures. The literature regarding this topic is mostly in the form of case reports and case series. PCMC tends to present in the elderly with predilection for the head and neck and on initial assessment it can be easily mistaken for a simple inclusion cyst. Although PCMC is often indolent in nature, in rare instances it can metastasize and should remain a differential diagnosis in a selected population. The significance in identifying PCMC is reliably differentiating it from metastatic mucinous adenocarcinoma. We present a review of literature and case of PCMC on the scalp of a 67-year-old female.

Primary Mucinous Adenocarcinoma of Skin: Myoepithelial Cells are a Clue to its Diagnosis

Primary mucinous adenocarcinoma is a rare adnexal neoplasm of eccrine gland. Fewer than 200 cases are reported in literature. Clinically, it can be mistaken as a benign lesion. The primary challenge in these lesions is to differentiate these rare primary lesions from more frequent mucinous secondary deposits. Morphologically, they are similar to metastatic deposits of mucinous carcinoma from other viscera such as breast, lung, or gastrointestinal tract. Use of ancillary techniques and a thorough metastatic work up are mandatory to differentiate these lesions from metastases. We report a case of primary mucinous carcinoma of nasojugal region in a 51-year-old female. It was diagnosed on fine-needle aspiration cytology, and later, the lesion was excised and diagnosis confirmed on histopathological examination and immunohistochemistry.

Helical Tomotherapy for Scalp Recurrence of Primary Eccrine Mucinous Adenocarcinoma

Primary cutaneous mucinous carcinomas originating from sweat glands are rare tumors with patterns of spread that are difficult to predict. We present a case of a five times recurring eccrine mucinous adenocarcinoma of the scalp, previously treated with surgery and adjuvant radiation therapy. After magnetic resonance imaging (MRI) and 18F-fluoro-2-deoxyglucose positron-emission tomography/computed tomography (18FDG-PET/CT), which documented local recurrence, the patient was considered eligible for salvage irradiation of the scalp. We decided to use helical tomotherapy, which combines conformity of dose delivery with the possibility of daily control of the setup accuracy. Forty gray (2Gy/fraction) to the planning target volume and 50 Gy (2.5Gy/fraction) to the biological target volume defined on the basis of 18FDGPET/CT was prescribed with a simultaneous integrated boost technique. After 12 fractions the patient was submitted to intermediate evaluation by 18FDG-PET/CT, which showed a partial response to the treatment. After 2, 4, 8, and 12 months, 18FDG-PET/CT showed a complete metabolic local response. This experience suggests a possible role of 18FDG-PET/CT-guided helical tomotherapy as an alternative to repeated and frequently demolitive surgery approaches.

Adnexal Carcinomas Treated With Mohs Micrographic Surgery: A Comprehensive Review

BACKGROUND

Adnexal carcinomas (ACs) are rare cutaneous malignancies of sweat gland or pilosebaceous origin. Optimal treatment and metastatic potential of AC are poorly defined. Mohs micrographic surgery (MMS) has been increasingly used to treat AC.

OBJECTIVE

To review selected primary cutaneous AC and their treatment outcomes with MMS.

MATERIALS AND METHODS

Literature review using PubMed search for articles related to primary cutaneous ACs.

RESULTS

Sebaceous carcinoma treated with MMS recurred and metastasized in 6.4% and 3.7%, respectively. Primary cutaneous mucinous carcinoma treated with MMS recurred and metastasized in 9.6% and 6.4%, respectively. After MMS, 4.7% of microcystic AC recurred with no reported metastases. After MMS, recurrences and metastases of trichilemmal carcinoma or hidradenocarcinoma have not been reported. Two (4.2%) regional lymph node metastases but no distant metastases or local recurrences have been reported in eccrine porocarcinoma. Squamoid eccrine duct tumor, pilomatrix carcinoma, and spiradenocarcinoma treated with MMS are also reviewed.

CONCLUSION

The rarity of ACs and the lack of comparative data on treatment makes conclusive recommendations on treatment difficult. Recent large case series and reviews suggest MMS is a useful and possibly superior treatment for AC and should be considered if primary cutaneous disease is suspected.

[Mucinous sweat gland carcinoma of the eyelid]

A 52-year-old patient presented with a painless nodular tumor of the upper left eyelid, which was first noticed 6 months prior to the initial presentation. The histopathological and immunohistochemical examination of the excised tumor revealed a mucinous sweat gland carcinoma. This very rare neoplasm (1/150,000 skin lesions) is located within the ocular adnexa in 40 % of cases. If completely excised the prognosis is usually good; however, due to the histological similarity to metastases of an adenocarcinoma, a hitherto unknown primary tumor at another site should be excluded.

Mucinous eccrine carcinoma of the eyelid: re-emphasizing the need for awareness of rare lesions

We report here the case of a man presenting with mucinous eccrine carcinoma (MEC) involving eyelid. This is a rare adencocarcinoma of the skin that originates from the deepest portion of eccrine sweat duct. The aim of our paper is to underline the importance of distinguishing MEC from metastatic carcinomas of the skin, making clinicians aware that what seems to be a harmless benign lesion may be a malignant one.

Mucinous carcinomas of the gallbladder: clinicopathologic analysis of 15 cases identified in 606 carcinomas

CONTEXT

There are virtually no data in the literature regarding the incidence, patterns, and clinicopathologic characteristics of mucinous carcinomas (MCs) of the gallbladder (GB).

OBJECTIVE

To determine the incidence of mucinous differentiation in invasive GB carcinomas and the clinicopathologic characteristics of those that qualify as MC.

DESIGN

Primary invasive GB carcinomas (n  =  606) were reviewed for mucinous differentiation. Some degree of mucin production was identified in 40 cases (6.6%); however, only 15 (2.5%) were qualified for the World Health Organization definition of MC (stromal mucin deposition constituting >50% of the tumor).

RESULTS

The mean age was 65 years, and the female to male ratio was 1.1 (versus 3.9 for conventional pancreatobiliary-type GB adenocarcinomas; P  =  .04). A significant proportion of the cases (8 of 12, 67%) presented with the clinical picture and intraoperative findings that were interpreted as acute cholecystitis. Mean and median tumor sizes were larger than those of conventional adenocarcinomas (4.8 and 3.4 cm versus 2.9 and 2.5 cm, respectively; P  =  .01). Most (13 of 15, 87%) cases presented with pT3 tumors (versus 48% for ordinary GB carcinomas; P  =  .01). Two cases had almost an exclusive colloid pattern (>90% composed of well-defined stromal mucin nodules that contained scanty carcinoma cells, most of which were floating within the mucin). Eight cases were of mixed-mucinous type, showing a mixture of colloid and noncolloid patterns. Five others had prominent signet-ring cells, both floating within the mucin (which constituted >50% of the tumor by definition) and infiltrating into the stroma as individual signet-ring cells in some areas. Immunohistochemical analysis performed on the 7 cases that had available tissue revealed CK7 in 4 of 7 (57%), CK20 in 2 of 7 (29%), MUC1 in 4 of 7 (57%), MUC2 in 6 of 7 (86%), CDX2 in 1 of 7 (14%), MUC5AC in 6 of 7 (86%), MUC6 in 0 of 7 (0%), and loss of E-cadherin in 6 of 7 (86%). The MLH1 and MSH2 were retained in 6 of 7 cases (100%). Follow-up information was available for 13 cases: 11 (85%) died of disease (1-37 months) and 2 (15%) were alive (23 months and 1 month). Overall survival of MCs was significantly worse than that of conventional adenocarcinomas (13 versus 26 months; P  =  .01); however, that did not seem to be independent of stage.

CONCLUSIONS

Mucinous carcinomas constitute 2.5% of GB carcinomas. They present with an acute cholecystitis-type picture. Most MCs are a mixed-mucinous, not pure colloid, type. They are typically large and advanced tumors at the time of diagnosis and thus exhibit more-aggressive behavior than do ordinary GB carcinomas. Immunophenotypically, they differ from conventional GB adenocarcinomas by MUC2 positivity, from intestinal carcinomas by an often inverse CK7/20 profile, from pancreatic mucinous carcinomas by CDX2 negativity, and from mammary colloid carcinomas by a lack of MUC6. Unlike gastrointestinal MCs, they appear to be microsatellite stable.

Mucinous eccrine carcinoma: a rare case of recurrence with lacrimal gland extension

Mucinous eccrine carcinoma (MEC) is a rare skin cancer of sweat gland origin with a high rate of recurrence. The most common sites are head and neck, with 40% of cancers found on the eyelid. The clinical appearance and differential diagnosis of MEC are highly varied, but histologically it is similar to metastatic carcinomas, specifically breast and colon. A diagnosis of primary MEC always warrants a full systemic workup to ensure that no other malignancy is present. This cancer is known for frequent recurrences, but rarely metastasizes to distant organs. MEC is resistant to both chemotherapy and radiation; surgical excision remains the treatment of choice in most cases. The authors report a unique case of extension of MEC to the lacrimal gland with a brief review of histologic characteristics of this tumor.

Malignant skin neoplasms

Skin cancers may be derived from any part of the skin, and the classification of all variants is extensive. Overall they are the most common cancers of the body, and include those that are highly mortal and those that are associated with an increased morbidity. In this review the most common skin cancers confronted by the clinician and their management are discussed. New associations are highlighted, as well as new information that can help the clinician to better understand the pathogenesis of many of these entities.

Primary mucinous carcinoma of the skin: a case of metastasis after 10 years of disease-free interval

Primary mucinous carcinoma of the skin (MCS) is a rare neoplasm. Clinically, it has a high local recurrence rate, but it is known to be a slow-growing benign tumor with a rare incidence of distant metastases. We present a case of primary MCS on the jaw that underwent tumor resection twice and was disease-free for 10 years after the second surgery. The patient had no evidence of local recurrence and distant metastasis until his 11th year follow-up. At that time, he was diagnosed with lung and bone metastasis and died 3 years after this. To our knowledge, this is the first case of MCS that presented with metastasis with more than 10-year disease-free interval. Since MCS is a slow-growing asymptomatic tumor, distant metastasis is difficult to diagnose without detailed radiological examination. We believe that computed tomography and resonance imaging should be performed for early diagnosis of metastasis even for cases with long-term disease-free interval, especially cases of local recurrence.