Primary mucinous carcinoma of the skin

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: 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 rare case of primary adenocarcinoma of the eyelid

Introduction. primary mucinous carcinoma of the eyelid skin is a rare adenocarcinoma of skin glands. This tumor rarely metastasizes but frequently recurs.

The study objective is to describe a rare clinical case of primary mucinous carcinoma of the eyelid skin, present macroscopic, histological and immunohistological descriptions of this pathology.

Clinical case. male, 66 years old, sought medical care due to a neoplasm of the lower eyelid. macroscopically a subcutaneous node 1.2 × 1.0 cm was observed, of yellow-brown color, gelatinous in section. microscopic examination showed that the tumor consists of islands of epithelial cells surrounded by mucinous “lakes”. Immunohistochemical examination showed Ck7, estrogen, p53 expression in the tumor cells, as well as absence of Ck20 expression. Based on the data of macro-, microscopic and immunohistochemical examinations, primary mucinous carcinoma of the eyelid skin was diagnosed. Observed morphological signs of this tumor allow to differentiate it from cancer metastasis.

Conclusion. primary mucinous carcinoma of the skin should be differentiated from metastasis of mucinous carcinoma of the breast, lung, colon, et al. macro- and microscopic signs of this tumor are subjective. Immunohistochemical examination is a more reliable diagnostic tool.

Endocrine mucin-producing sweat gland carcinoma and associated primary cutaneous mucinous carcinoma: Review of the literature

BACKGROUND

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare, low-grade, cutaneous adnexal carcinoma with neuroendocrine differentiation. It is considered to be a precursor of invasive neuroendocrine type primary cutaneous mucinous carcinoma (PCMC).

OBJECTIVE

To review clinicopathological literature summary of EMPSGC and associated neuroendocrine PCMC from all reported cases and compare its behavior vs non-neuroendocrine PCMC data reported in the literature.

METHODS

A review of English literature of all EMPSGC cases with and without associated PCMC was carried out.

RESULTS

EMPSGC was associated with invasive neuroendocrine type PCMC in 35.7% of cases. We found the recurrence rate of PCMC associated with EMPSGC of about 12.3%, which is much less than the 30% recurrence rate reported for the non-neuroendocrine subtype of PCMC. The non-neuroendocrine subtype of PCMC shows a 4% and 11% rate of distant and lymph node metastasis, respectively, vs EMPSGC-associated neuroendocrine type of PCMC, which is very indolent and only one recent case of locoregional metastasis out of 190 EMPSGC cases has been reported so far.

LIMITATION

Limitation of our study includes data derivation from case reports and case series in the literature.

CONCLUSION

The prognostic benefits for this cohort of patients may be considered in their overall management.

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.

An Update on Endocrine Mucin-producing Sweat Gland Carcinoma: Clinicopathologic Study of 63 Cases and Comparative Analysis

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare, low-grade adnexal neoplasm with predilection for the periorbital skin of older women. Histologically and immunophenotypically, EMPSGC is analogous to another neoplasm with neuroendocrine differentiation, solid papillary carcinoma of the breast. Both lesions are spatially associated with neuroendocrine mucinous adenocarcinomas of the skin and breast, respectively. EMPSGC is ostensibly a precursor of neuroendocrine-type mucinous sweat gland adenocarcinoma (MSC), a lesion of uncertain prognosis. Non-neuroendocrine MSC has been deemed locally aggressive with metastatic potential, and previous works speculated that EMPSGC-associated (neuroendocrine-type) MSC had similar recurrence and metastatic potential with implications for patient follow-up. Only 96 cases of EMPSGC have been reported (12 cases in the largest case series). Herein, we present 63 cases diagnosed as "EMPSGC" in comparison with aggregated results from known published EMPSGC cases. We aim to clarify the clinicopathologic features and prognostic significance of the neuroendocrine differentiation of EMPSGC and its associated adenocarcinoma and to determine the nosological relevance of EMPSGC association in the spectrum of MSC histopathogenesis. Results established an overall female predominance (66.7%) and average presenting age of 64 years. EMPSGC lesions were associated with adjacent MSC in 33.3% of cases. The recurrence rate for neuroendocrine-type MSC was ~21%, less than the reported 30% for non-neuroendocrine MSC. There were no cases of metastasis. EMPSGC and neuroendocrine-type MSC are distinct entities with more indolent behavior than previously reported, supporting a favorable prognosis for patients.

Primary mucinous eccrine carcinoma of the buccal space: A case report and review of the literature

IMPORTANCE

Mucinous eccrine carcinoma is a rare entity that most commonly affects the head and neck. Due to its low frequency of occurrence, review of its etiology, histopathology, and treatment strategies is beneficial to all clinicians who may encounter similar appearing masses.

OBSERVATION

An 84-year-old male presented with a blue mass on the left cheek. This mass started as a small bump and grew significantly over one year. His primary care physician monitored its growth and ultimately referred to an otolaryngologist. Imaging findings revealed a multi-lobular solid and cystic left buccal lesion. FNA was suggestive of low grade mucoepidermoid carcinoma.

INTERVENTION

Patient underwent surgical excision with primary closure of the defect. Frozen section was consistent with low grade salivary malignancy. Final pathology revealed primary mucinous eccrine carcinoma of the skin.

CONCLUSIONS AND RELEVANCE

Mucinous eccrine carcinoma is a rare entity commonly seen in the head and neck region. Mucinous deposits to the skin from primaries elsewhere in the body are much more common than primary lesions of the skin. Histology is a key component of the diagnosis but full oncologic workup is required. Treatment typically includes wide local excision with possible adjuvant chemotherapy or radiation for high risk features.

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.

Primary mucinous adenocarcinoma of the scalp: A case report and literature review

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Primary mucinous adenocarcinoma of the skin is a rare tumour.

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Distinguishing between this primary neoplasm and the more frequently encountered metastatic mucinous deposits on the skin from primaries elsewhere is a diagnostic dilemma.

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Because of the high rate of recurrence, adequate excision with wide margins is advocated. Moh’s micrographic surgery can be a particularly advantageous treatment modality in this setting.

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Proper patient counselling and follow-up are important in treating this low-grade, indolent and frequently recurring tumour.

Introduction

Primary mucinous adenocarcinoma or mucinous eccrine carcinoma of the skin is a rare malignant neoplasm showing predilection to the head and neck. Distinguishing between these primary neoplasms and the more frequent metastatic mucinous deposits on the skin from primaries in the breast and gastrointestinal tract constitutes a diagnostic dilemma.

Presentation of case

We report a case of a 61-year-old lady who presented with a slow-growing, painless scalp nodule. Upon excision, it was diagnosed as “primary mucinous adenocarcinoma”. An extensive work-up in search for another primary tumour failed to show a primary malignancy elsewhere and the diagnosis of a primary eccrine mucinous adenocarcinoma of the skin was rendered.

Discussion

A review of the literature on this entity is presented, discussing diagnostic challenges and therapeutic options that of interest to surgeons, pathologists and dermatologists.

Conclusion

These tumours are indolent and low-grade, with a tendency for local, sometimes multiple, recurrences. Proper patient counselling and follow-up are important in treatment. Sound collaboration between clinicians and pathologists, for good therapeutic results, is of utmost importance.

Mucin-producing sweat gland carcinoma of the eyelid: diagnostic and prognostic considerations

PURPOSE

To describe the clinical and pathologic characteristics of mucin-producing sweat gland carcinoma of the eyelid and to determine whether neuroendocrine differentiation is of prognostic significance.

DESIGN

Retrospective interventional case series.

METHODS

Search of the New York Eye and Ear Infirmary pathology database between 1990 and 2011 identified 16 patients with mucin-producing sweat gland carcinoma. Clinical, histopathologic, and immunohistochemical analyses were performed on all identified cases.

RESULTS

The patients presented with vascularized, focally cystic, nonulcerated eyelid margin lesions. Histopathologic evaluation showed that 4 lesions (25%) had a cystic, papillary, and solid growth pattern with an in situ component, 7 (44%) were pure invasive mucinous carcinomas, and 5 (31%) demonstrated both growth patterns. Immunohistochemical analysis of 15 tumors showed that pure cystic/papillary lesions had a significantly greater percentage of synaptophysin-immunoreactive cells (P = .036). There was no significant difference in the number of neuroendocrine markers expressed or in the intensity of immunostaining among the 3 different growth patterns. Re-excision for margin clearance was performed in 8 of 13 cases (61.5%). Two of 13 lesions recurred (15%); 1 of these was an in situ tumor with cystic morphology and neuroendocrine differentiation and the other was pure invasive mucinous carcinoma. None of the lesions metastasized.

CONCLUSIONS

Mucin-producing sweat gland carcinoma pathologically represents a continuum, from an in situ lesion to a classic, invasive mucinous carcinoma. Immunohistochemical evidence of neuroendocrine differentiation can be observed in all lesions and does not appear to have a prognostic significance, arguing against the utility of immunohistochemical subtyping of mucinous sweat gland carcinomas.

Mucinous sweat gland adenocarcinoma of the eyelid - current knowledge of a rare tumor

PURPOSE

To review the medical literature on mucinous sweat gland adenocarcinoma of the eyelid (MSA) and present two new cases.

METHODS

Details of published case reports and small series (between 1971-2010) were evaluated and summarized including two patients diagnosed and treated at our institution. Data regarding age, gender, ethnicity, precise location, clinical presentation, treatment and follow up of each patient were collected.

RESULTS

25 reports describing 55 patients were found in the medical literature. The mean age was 61.3 years (30-87), 22(59%) were male and 28(80%) were Caucasian. In 23(44.2%) patients the lesion was in the lower lid, in 20(38.5%) in the upper lid, in 3(5.7%) involving both lids and in 6(11.6%) in a canthus. In 12(21.8%) patients a lesion with a benign diagnosis was previously excised from the same location. In 2 of them histological re-examination resulted in a diagnosis of MSA. Intraorbital involvement was found in 2(3.6%) patients. Regional lymph node metastasis was found in 2(4.4%) patients. Surgical excision was the treatment of choice using Mohs' micrographic-controlled excision technique in recent years. Radiotherapy was applied to 2 patients with clinical resolution in 1. Recurrence of the tumor was reported in 14(30%) patients.

CONCLUSIONS

MSA is a rare tumor of the eyelid with no clinically distinguishing features. It should be suspected particularly with recurrent eyelid lesions and must be differentiated from metastatic disease. The tumor may extend into the orbit and metastasize regionally. Surgical removal with continued regular follow-up examination is the treatment of choice.

A case of primary cutaneous mucinous carcinoma with neuroendocrine differentiation

Primary cutaneous mucinous carcinoma is a rare malignant tumor that originates from the deepest portion of the eccrine sweat duct. Common sites of involvement are the face and scalp. Biopsy shows dermal epithelial cell islands embedded in mucin pools separated by fibrous septae. It is difficult to differentiate this tumor histologically from metastatic adenocarcinoma. Recurrence after excision is common but metastases are rare. We report a primary cutaneous mucinous carcinoma with neuroendocrine differentiation on the right cheek of a 63-year-old man.

Primary mucinous eccrine carcinoma of the skin--a rare clinical tumor with many differential diagnoses

Primary mucinous eccrine carcinoma of the skin is an extremely rare tumor most frequently occurring in the face or capillitium. It is felt to be an eccrine carcinoma, characterized by slow progress and unpredictable locally infiltrative growth. Therefore micrographic surgery is important to avoid local recurrence. It can be difficult to differentiate this carcinoma histologically from cutaneous metastases of breast or gastrointestinal tumors. Because of this, a primary staging in affected patients is essential.

Endocrine mucin-producing sweat gland carcinoma: report of a case and review of the literature

Mucinous carcinoma of skin (MCS) is an uncommon adnexal tumor of disputed differentiation. In 1995, Rahilly et al. reported a case of MCS with neuroendocrine differentiation (E-MCS). Since that report, seven additional cases have been published. Here, we report on a case of E-MCS and discuss the differential diagnoses.

Mucinous Eccrine Adenocarcinoma of the Periocular Region

PURPOSE

To report 4 patients with mucinous eccrine adenocarcinoma of the periocular region.

METHODS

Interventional case series of 4 patients with mucinous eccrine adenocarcinoma of the periocular region treated at 2 centers.

RESULTS

Two patients with mucinous eccrine adenocarcinoma of the upper eyelid, 1 with mucinous eccrine adenocarcinoma of the lower eyelid, and 1 with mucinous eccrine adenocarcinoma of the eyebrow were included in this report. The lower eyelid lesion and the eyebrow lesion recurred after Mohs micrographic surgery. Both recurrent lesions were treated with Mohs micrographic surgery and postoperative adjuvant external-beam radiation therapy. The other 2 primary tumors were treated with wide local excision with frozen section control of margins and did not recur. The follow-up time after the most recent surgical procedure ranged from 8 to 17 months (median, 12 months).

CONCLUSIONS

Mucinous eccrine adenocarcinoma is a rare ocular adnexal neoplasm that can involve the eyelid and periocular skin, can be locally invasive, and has a high risk of local recurrence despite Mohs surgery.

Oestrogen and progesterone receptors in primary mucinous carcinoma of skin

A 74-year-old man presented with a recurrent indolent growth in the left axilla. Fine-needle aspiration cytology and histopathological examination showed a picture of mucinous adenocarcinoma. Clinical examination and systemic investigations failed to detect any primary lesion elsewhere and hence, a diagnosis of primary mucinous carcinoma of the skin was made. This tumour shows histological resemblance to mucinous carcinoma of breast. We also demonstrated expression of oestrogen and progesterone receptors in this tumour. This observation suggests that there is a potential of using antioestrogenic therapy in patients with primary cutaneous mucinous carcinoma, especially because of its high rate of local recurrence.

Endocrine Mucin-Producing Sweat Gland Carcinoma

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is an underrecognized low-grade carcinoma with predilection to the eyelid. Only 4 cases of this entity have been described in the literature. Here, we describe 12 cases of EMPSGC. The lesions were twice as frequent in females than males with an average age of 70 years (range, 48-84 years). Clinically, they presented as a slowly growing cyst or swelling. The most common site of occurrence was the lower eyelid (8 cases). Two lesions occurred on the upper eyelid and 2 on the cheek. Histologically, they were well-circumscribed, typically multinodular tumors with solid or partially cystic nodules, frequently showing areas of papillary architecture. Focal cribriform arrangements were also present. The nodules were formed by uniform small- to medium-sized oval to polygonal epithelial cells with lightly eosinophilic to bluish cytoplasm. The nuclei were bland with diffusely stippled chromatin and inconspicuous nucleoli. Intracytoplasmic and extracellular mucin was usually present. Mitotic activity was present but never brisk. All tumors examined immunohistochemically expressed at least one neuroendocrine marker, synaptophysin or chromogranin. CD57 and neuron specific enolase, secondary markers of neuroendocrine differentiation, were expressed in most cases. All tumors tested expressed estrogen and progesterone receptors, cytokeratin 7, low molecular cytokeratin Cam5.2, and epithelial membrane antigen and were negative for cytokeratin 20 and S-100 protein. Calponin, smooth muscle actin, and p63 immunohistochemical stains did not disclose myoepithelial cells around larger tumor nests in most cases, supporting the notion that EMPSGC is an invasive carcinoma. In 10 cases, cystic areas lined by benign epithelium indistinguishable from eccrine ducts were present. In some foci, the benign ductal epithelium was undermined or replaced by carcinoma in situ with similar cytologic features to the solid or papillary areas of EMPSGC. Myoepithelial cells were preserved in the areas of in situ carcinoma. In 6 cases, EMPSGC was associated with invasive mucinous carcinoma. In situ carcinoma and mucinous carcinoma also expressed neuroendocrine markers. Clinical follow-up showed no recurrences or metastases, consistent with low-grade carcinoma. The series provides histologic evidence for a multistage progression of noninvasive sweat gland neuroendocrine carcinoma to EMPSGC and then to mucinous carcinoma of the eyelid. Although the data from this series support the notion that the prognosis of EMPSGC and mucinous carcinoma is good, longer follow-up is needed for better understanding of their pathogenesis and clinical behavior.

Primary cutaneous mucinous carcinoma of the eyelid in a young male

Primary cutaneous mucinous carcinoma of the eyelid is an adenocarcinoma of the eccrine glands. It is rare and locally aggressive but the prognosis following local excision, confirmed with tumour-free margins, is good. This tumour is usually described in the elderly. We present the occurrence, clinical and histological features, and management of this tumour in a young male.A 36-year-old male presented with a small cystic right lower lid lesion, which had increased in size and pigmentation over two years. He underwent excision biopsy for diagnostic purposes followed by Moh's micrographic surgical removal. The defect was repaired with an upper eyelid skin graft. A full oncological screen including whole-body computed tomography scan excluded the presence of primary mucinous carcinoma elsewhere and any metastatic spread. There has been no recurrence of tumour 18 months following excision. Ophthalmologists should be aware of the occurrence of this tumour in a younger age group than previously described. Moh's micrographic surgery is the most suitable method of treatment following exclusion of both distant primaries and metastases.

Mohs Micrographic Surgery of Primary Cutaneous Mucinous Carcinoma Using Immunohistochemistry for Margin Control

BACKGROUND

Primary cutaneous mucinous carcinoma is a rare adnexal malignancy with a high recurrence rate following conventional excision and the potential for aggressive local invasion.

OBJECTIVE

To enhance the microscopic detection of mucinous carcinoma in Mohs micrographic surgical sections by incorporating rapid immunohistochemical staining.

METHODS

Standard Mohs micrographic surgical technique was used in conjunction with frozen section immunohistochemistry using an antibody to low-molecular-weight cytokeratin.

RESULTS

Rapid immunoperoxidase staining using low-molecular-weight cytokeratin detected residual foci of mucinous carcinoma that were difficult to identify on routine frozen sections. Immunostaining was strongly positive in areas with clear evidence of tumor by routine histology, as well as in adjacent areas on a subsequent stage where frozen sections were equivocal or negative. Immunostaining was distinctly negative at the final surgical margin, which was shown by en face permanent sections to be free of tumor. The patient has been free of recurrence for 3 years.

CONCLUSION

Immunoperoxidase-guided Mohs micrographic surgery using low-molecular-weight cytokeratin enhances the sensitivity for detection of mucinous carcinoma, and may help contribute to complete tumor removal.

Primary Cutaneous Mucinous Carcinoma Initially Diagnosed as Metastatic Adenocarcinoma

The authors report a rare case of primary mucinous carcinoma of the skin initially diagnosed as a metastatic adenocarcinoma. The tumor occurred in the right axilla in a 75-year-old man. Initial pathological diagnosis was metastatic adenocarcinoma. However, no primary focus was found in the body. The revised diagnosis by the authors was primary cutaneous mucinous carcinoma. The tumor (1.5 cm) was characterized by proliferation of atypical epithelial cells arranged in cell nests with many pseudolumens resembling adenoid cystic carcinoma. It was also characterized by much mucinous stroma or pool around tumor cells. No apparent eccrine or apocrine differentiation was noted histologically and immunohistochemically. The present case suggests that primary cutaneous mucinous carcinoma may be misdiagnosed as metastatic adenocarcinoma, and that it may resemble adenoid cystic carcinoma.

Mucinous carcinoma of the skin with apocrine-type differentiation: immunohistochemical studies

We investigated the pathway of differentiation in a case of mucinous carcinoma of the skin (MCS) arising on the right temple of a 70-year-old man. Histopathologic findings of the tumor showed evidence of apocrine-type differentiation such as distinctive decapitation secretion. Additionally, by employing a panel of antibodies, the immunohistochemical staining pattern of tumor cells was shown to be compatible with that of apocrine glands. Although the differentiation of this neoplasm remains controversial, the findings in our case suggest apocrine differentiation.

A case of primary mucinous carcinoma of the scalp treated with mohs surgery

BACKGROUND

Primary mucinous carcinoma of the skin is a rare sweat gland malignancy that is associated with locally aggressive behavior and a high rate of local recurrence following simple excision.

OBJECTIVE

A patient with primary mucinous carcinoma of the scalp, which was treated with Mohs micrographic surgery (MMS), is described.

METHODS

Case report and literature review.

RESULTS

The patient underwent MMS to remove the tumor. Thirty months after the procedure, the patient remains tumor free.

CONCLUSION

Simple excision of primary mucinous carcinoma of the skin is associated with a high recurrence rate. Given the low rate of metastasis and characteristic histologic tumor continuity associated with primary mucinous carcinoma of the skin, as well as the tendency for the tumor to involve cosmetically sensitive areas, such as the face and eyelids, MMS appears to represent a preferable treatment alternative for this particular sweat gland tumor. MMS appears to be associated with a very low risk of tumor recurrence.

Immunohistochemical analysis of cytokeratin and human milk fat globulin expression in mucinous carcinoma of the skin

BACKGROUND

Mucinous carcinoma of the skin (MCS) is a rare epithelial tumor which arises primarily in the skin. Metastatic MC from extracutaneous sites, especially breast or colon, mimics MCS and cannot be differentiated from MCS by routine histology alone.

METHODS

Nine cases of MCS were analyzed immunohistochemically using monoclonal antibodies against cytokeratins (CKs) and human milk fat globulin 1 (HMFG) in order to clarify their nature and compare the immunophenotypes with those of other MCs studied in the literature.

RESULTS

Expression of simple epithelial CKs in most of the tumor cells of all cases studied and co-expression of simple and stratified epithelial CKs in some tumor cells of two cases were recognized. CK 20 expression could not detected in any tumor cells. Focal HMFG expression in the luminal or outer surface of the nests was observed in three cases.

CONCLUSION

From CKs expression, MCS was speculated to differentiated mainly toward the secretory cells of the sweat glands, and some tumor cells toward the transient portion between the dermal duct and the secretory portion. Focal HMFG expression suggested either a consequence of malignant transformation or apocrine differentiation. No expression of CK 20 in MCS suggests that we may exclude the diagnosis of metastatic colorectal MC which expressed CK 20.

Carcinomas of sweat glands: report of 60 cases

CONTEXT

Several aspects of sweat gland carcinomas (incidence, classification, diagnosis, and behavior) have not been definitively clarified and need to be studied further.

OBJECTIVE

The clinicopathologic findings of a large series of sweat gland carcinomas, collected during a period of 15 years, are presented.

METHODS

Sixty sweat gland carcinomas (41 porocarcinomas, 3 syringomatous carcinomas, 8 ductal carcinomas, 5 adenoid cystic carcinomas, and 3 mucinous carcinomas) were analyzed histologically and immunohistochemically.

RESULTS

Porocarcinomas were composed of eosinophilic and clear atypical cells arranged in solid-cystic lobular masses. These tumors were divided into 2 subgroups: horizontal porocarcinomas, showing a prominent intraepidermal component, and nodular porocarcinomas, which demonstrated predominant nodular growth. Syringomatous carcinomas presented keratinizing and nonkeratinizing cysts, dilated tubules (sometimes with a "tadpole" appearance), small neoplastic ducts, solid islands, and cellular cords. Ductal carcinomas were characterized by a prominent formation of tubules, solid islands, and cellular cords. Adenoid cystic carcinomas presented a characteristic pattern, showing basaloid monomorphous cells with moderately atypical nuclei, arranged in cribriform or solid islands and in tubular structures. Mucinous carcinomas were composed of moderately atypical cells with eosinophilic vacuolated cytoplasm, forming solid and cystic islands floating in large mucin pools. Immunohistochemically, cytokeratin was found in neoplastic cells in all cases, carcinoembryonic antigen was detected in 73% of cases, and actin-positive (myoepithelial) cells were not found.

CONCLUSIONS

Although numerous studies have been published in recent years, the histologic features, histogenesis, and classification of sweat gland carcinomas still remain controversial and need to be clarified by further studies.