Squamous metaplasia of sebaceous gland

Squamous metaplasia in the skin has been reported in the eccrine ducts as eccrine squamous syringometaplasia (ESS). To our knowledge, squamous metaplasia of sebaceous gland (SMSG) has not been described in human skin. Twenty-two biopsy specimens from patients with pressure lesions after cardiac surgery with extracorporeal circulation were evaluated for the presence of SMSG. Squamous metaplasia of sebaceous gland was identified in five of the eight scalp biopsies and none of the buttock biopsies. The squamous metaplasia began in the germinative outer layer and advanced in a centripetal way. We believe that SMSG is an unspecific change of the sebaceous cells secondary to a chronic injury. Ischemia appears to play a mayor role, but other factors such as chronic trauma or toxicosis can not be ruled out.     

Cytomegalovirus-induced syringosquamous metaplasia.

An unusual case of syringosquamous metaplasia of the eccrine ducts caused by cytomegalovirus (CMV) is presented. The patient was HIV positive and had extensive excoriation of the perineum and vulva. Biopsy revealed the presence of herpes simplex virus (HSV) inclusions in the necrotic exudate, a CMV vasculitis and extensive involvement of the eccrine ducts. In addition to containing typical CMV inclusions, the eccrine ducts showed proliferation and squamous metaplasia. Inclusions of HSV were not seen within the eccrine ducts by light microscopy or immunohistochemistry. The extensive proliferation with accompanying squamous metaplasia superficially can resemble an infiltrating squamous carcinoma, but this was not evident to a great extent in this case. To the best of our knowledge, our case represents the first of syringosquamous metaplasia of eccrine ducts caused by CMV infection.     

Eccrine squamous syringometaplasia secondary to cutaneous extravasation of docetaxel: report of three cases

Eccrine squamous syringometaplasia is characterized by the metaplasia of cuboidal epithelial cells of the eccrine sweat ducts into squamous epithelial cells. It has been associated with several conditions including chemotherapy‐related bilateral dermatitis, an entity that can take place in body areas rich in eccrine glands, as well as in acral erythema related to chemotherapy. Only a few cases because of cutaneous extravasation of chemotherapy have been previously reported. We report three cases of eccrine squamous syringometaplasia secondary to extravasation of docetaxel.     

Syringomatous hyperplasia and eccrine squamous syringometaplasia associated with benoxaprofen therapy

Two patients are described, each of whom developed multiple eruptive lesions on sun-exposed areas within days after starting benoxaprofen therapy. The lesions were 2- to 5-mm papules suggestive of syringomas, and microscopically showed squamous metaplasia of eccrine ducts and focal necrosis of eccrine keratinocytes as well as prominent eccrine hyperplasia. In both cases, the lesions resolved completely after benoxaprofen therapy was discontinued. A theoretical basis for these findings is discussed.     

Malignant transformation of eccrine tumors

Malignant transformation occurred in pre-existing sweat gland tumors in 7 patients. Three lesions showed an histologic pattern of eccrine spiradenoma, 2 eccrine poroma, one cylindroma and one papillary eccrine adenoma. Malignant transformation was histologically characterized by the presence of solid tumor areas populated with large cells having irregularly shaped nuclei and mitotic figures. There were multiple foci of squamous metaplasia, areas of loss of basement membrane and invasion of the surrounding connective tissue.     

Eccrine mucinous metaplasia associated with an apocrine cystadenoma

Mucinous metaplasia occurs uncommonly in cutaneous pathology, usually at specialized anatomic locations (genitalia, palms, and soles) and within restricted pathologic contexts (inflammation and trauma). Here, we report a unique case of eccrine mucinous metaplasia associated with an apocrine cystadenoma. A 13-year-old girl had an asymptomatic, 4-mm nodule on the chest. Histopathology demonstrated a typical apocrine cystadenoma in the upper and middle dermis. Adjacent to this lesion was a cluster of coiled eccrine secretory glands, of which the inner layer was almost entirely replaced by benign-appearing cells containing abundant, non-sulfated acid mucopolysaccharides. At 10 months' follow up, there was no recurrence. Our case demonstrates that, very uncommonly, mucinous metaplasia may be associated with a pathogenetically separate, adjacent proliferative adenomatous lesion, in this instance, an apocrine cystadenoma.     

Adenomatous eccrine metaplasia--a novel reaction pattern

We recently observed atypical adenomatous metaplasia of eccrine glands in an excisional biopsy of squamous cell carcinoma (SCC). This led us to this study in an effort to ascertain whether this reaction pattern is common to all excisional biopsies and, depending on its presence in association with residual tumor, whether it is lineage specific. We performed a retrospective review of 201 excisional biopsies and noted that adenomatous metaplasia was present in 35 of 201 (17%) of the cases, of which 19 had residual tumor. Adenomatous metaplasia seemed to be more frequent in epithelial neoplasms such as basal cell carcinomas 15 of 94 (16%) and SCCs 13 of 61 (21%) although only (3 of 41) 7% of nevomelanocytic proliferations exhibited this change. Residual tumor was noted in association with adenomatous metaplasia, in 11 of 15 cases (73%) in the basal cell carcinoma subgroup, in 8 of 13 cases (62%) in the SCC subgroup, and in none from the nevomelanocytic subgroup. Comparing frequencies of adenomatous metaplasia across groups, only SCC specimens with residual tumor demonstrated a statistically significant increase compared with nevomelanocytic neoplasm (35% vs. 7%, P = 0.01). Findings from the current study expand the spectrum of metaplastic change involving eccrine glands to include adenomatous metaplasia. Given that it seems to be more common to epithelial malignancies, it seems reasonable to posit that this reaction pattern is the consequence of hitherto undefined proteins induced by epithelial tumor cells resulting in exuberant stimulation of eccrine glands, although immunohistochemical and molecular studies are required to define the precise cause.     

Syringosquamous metaplasia. A distinctive eruption in patients receiving chemotherapy

Squamous metaplasia of the upper portion of the sweat ducts has been observed in four patients who received chemotherapy; two patients with acute myelogenous leukemia, one patient with testicular carcinoma, and one patient with anaplastic carcinoma of the lung. This change is different (but perhaps related) from what is described in neutrophilic eccrine hidradenitis in patients with acute myelogenous leukemia and other tumors after chemotherapy. Syringosquamous metaplasia may be confused with well differentiated squamous cell carcinoma histologically.     

Cancerization of eccrine sweat ducts in Bowen's disease as studied by light microscopy, DNA spectrophotometry and immunohistochemistry.

This study assesses the incidence, histogenesis, and significance of eccrine sweat duct involvement in Bowen's disease (BD). In a review of 96 cases of BD, four showed eccrine duct involvement on hematoxylin and eosin-stained histologic sections. One case was analyzed for deoxyribonucleic acid (DNA) ploidy by using computerized image analysis on Feulgen-stained slides. Sections were also stained immunohistochemically, using antibodies to carcinoembryonic antigen (CEA), gross cystic disease fluid protein (GCDFP), and S-100 protein, and for cytokeratins (CAM 5.2, AE 1/3). Our results showed that, in BD, (a) the eccrine sweat ducts can be extensively involved by atypical cells, (b) the atypical eccrine duct cells had an aneuploid DNA pattern, and (c) the atypical eccrine duct cells were negative for CEA, GCDFP, and S-100 protein but were positive for cytokeratins. We conclude that (a) the frequency of eccrine duct involvement in BD is relatively low (approximately 4 to 9%), (b) the aneuploid DNA pattern makes a benign squamous metaplasia unlikely, (c) the immunohistochemical results exclude coincidental Paget's disease or carcinoma of eccrine sweat glands, (d) the involvement of eccrine sweat ducts may represent a direct extension of the neoplastic epidermal keratinocytes, and (e) this process may have practical implications in the recurrence of superficially treated cases of BD.     

Adenodermatofibroma possessing dilated glandular structures with eccrine features: A case study

Adenodermatofibroma is a newly recognized variant of dermatofibroma characterized by dense proliferation of fibroblasts and histiocytes admixed with dilated glandular structures showing apocrine secretion. Only five cases of adenodermatofibroma have been reported to date. We report an additional case of adenodermatofibroma on the back of a 67‐year‐old female. In addition to the dilated glandular structures, nondilated eccrine units were present at the upper periphery of the lesion, above which the normal eccrine glands reside. Although decapitation secretion was observed in the nondilated eccrine units at the upper periphery of the lesion, this was not observed in the dilated glandular structures. The inner cells of the dilated glandular structures were S‐100 positive, similar to those of the secretory portion of eccrine glands. We considered the glandular structures in our patient were derived from the entrapped eccrine units. We suggest that the term “apocrine metaplasia” be applied to eccrine units showing decapitation secretion.     

Lichen planoporitis: keratosis lichenoides chronica revisited

We report a 70-year-old woman who over a 7-year period developed a widespread violaceous, reticulate and striate eruption with a keratotic component in a clinical pattern previously described as keratosis lichenoides chronica. Multiple biopsies showed a lichenoid reaction centred over the acrosyringium and eccrine ducts entering the epidermis. The acrosyringeal ducts were surrounded by an epidermis that was associated with saw-tooth acanthosis. The ducts displayed hypergranulosis and keratin plugs that extended into the stratum corneum. In the upper dermis the eccrine ducts showed squamous metaplasia with liquefaction of degeneration of their basal cells as well as apoptotic keratinocytes. The subepidermal acrosyringial zone and the eccrine ducts were associated with lymphocytic inflammation and fibrosis. These histopathological findings may represent the counterpart of lichen planopilaris targeting the eccrine ducts. The clinical features defining keratosis lichenoides chronica probably represents a heterogeneous group of conditions including this distinctive subset of lichen planus which we have termed lichen planoporitis.     

Eccrine squamous syringometaplasia and syringomatous hyperplasia in association with linear scleroderma

It is now well recognized that syringomatous hyperplasia with squamous syringometaplasia is a type of pseudoepitheliomatous hyperplasia responding to a variety of stimuli. We report a case of linear scleroderma with this process. Histopathology of the lesion showed numerous solid and cystic epithelial structures with squamous metaplasia within typical sclerodermatous skin lesions. Although the pathogenesis of the process remains unclear, dermal-derived growth factors in scleroderma and/or the mechanical effect of sclerosis could stimulate the proliferative response of eccrine epithelium. To the best of our knowledge, the association of syringomatous hyperplasia with eccrine squamous syringometaplasia and linear scleroderma has not been described previously.     

Tamoxifen-induced eccrine squamous syringometaplasia

A 74-year-old woman had carcinoma of her right breast for which surgery was performed. Four weeks following the start of tamoxifen therapy, she developed papules and plaques over her face, trunk and limbs. A skin biopsy showed perivascular and periadnexal mixed inflammatory cellular infiltrate with fibroplasia. Notably, the dermis also showed squamous epithelial islands, which in foci were noted to be closely associated with eccrine epithelium. This was confirmed with double peroxidase - alkaline phosphatase immunohistochemistry - the eccrine lumina highlighted with carcinoembryonic antigen (polyclonal) and the squamous metaplasia positive for cytokeratin 5/6. Eccrine squamous syringometaplasia was diagnosed. With close clinicopathological correlation, the cutaneous eruption was attributed to tamoxifen. Following discontinuation of the drug, the eruption resolved. Eccrine squamous syringometaplasia has been reported to occur in association with diverse conditions, including skin ulcers, burns and as a cutaneous adverse drug reaction, most commonly to chemotherapeutic drugs. This is believed to be the first report involving tamoxifen.     

Tubular adenoma of the skin with follicular and sebaceous differentiation: A report of two cases

The main controversies regarding tubular apocrine adenoma and papillary eccrine adenoma are whether they are two distinct entities or are the very same tumor, and if so, which lineage of differentiation (apocrine versus eccrine) it pursues. We report two cases of tubular adenoma with follicular and, in one case, additionally, sebaceous differentiation. The features in both cases indicated apocrine differentiation of the tubular component. One patient was a 60-year-old woman with a 1-year history of a solitary nodule on the scalp. The other patient was a 48-year-old woman with a solitary nodule of unknown duration located on the back. In both patients, the tumors were surgically removed. The patients were alive and well 2.5 and 2 years after surgery, respectively. The histologic features that both cases had in common included the combination of a tubular adenoma, foci of follicular differentiation, and areas of immature squamous metaplasia. In case 1, follicular differentiation was seen in the form of strands of basaloid cells surrounded by a stroma resembling the embryonic perifollicular sheath. Some aggregates of basaloid cells were juxtaposed with small collections of plump fibroblasts, imparting a resemblance to rudimentary follicular germs associated with follicular papillae. Many minute lumens surrounded by more eosinophilic cells were seen within the strands. In case 2, follicular differentiation was seen as several infundibulocystic structures surrounded by isthmic epithelium housing scattered mature sebocytes. In addition, there were areas reminiscent of desmoplastic trichoepithelioma (columnar trichoblastoma). In both cases, the areas with immature squamous metaplasia were represented by solid nodules that were mostly devoid of lumens and a peripheral basal/myoepithelial cell layer. In conclusion, these two cases of cutaneous tubular adenoma with accompanying follicular and sebaceous differentiation give further support to the proposition that the majority of these neoplasms have apocrine differentiation. Rare cases occurring in the sites normally devoid of apocrine glands may represent the eccrine counterpart.     

Eccrine squamous syringometaplasia

Squamous syringometaplasia (SS) is defined as a mature squamous metaplasia of the eccrine ducts. We prospectively evaluated its frequency and clinical and pathological features in a series of 21 patients. SS was found in association with several diseases, chiefly chronic ulcers. The patients'ages ranged between 20 and 80 years and there was no sex predominance. The involved eccrine ducts were usually located in the superficial and mid dermis and displayed inner keratinization. The stimulus required for SS is unknown. Differential diagnosis between SS and well-differentiated squamous cell carcinoma (SCC) depends on the preservation of a lobular configuration and the absence of epithelial dysplasia or invasion.     

Chemotherapy‐induced eccrine squamous syringometaplasia in an infant

There are few reports of chemotherapy‐induced eccrine squamous syringometaplasia in children. We report the first case of an infant developing this condition after treatment with busulfan, fludarabine, and antithymocyte globulin in preparation for bone marrow transplantation. Twenty‐eight days after transplantation, the infant developed faintly erythematous papules and plaques on the bilateral axillae, inguinal folds, and sites of adhesives. Punch biopsy revealed eccrine glands with dyskeratotic cells and focal squamous metaplasia consistent with chemotherapy‐induced eccrine squamous syringometaplasia.     

Human papillomavirus-associated plantar epidermoid cyst related to epidermoid metaplasia of the eccrine duct epithelium: a combined histological, immunohistochemical, DNA-DNA in situ hybridization and three-dimensional reconstruction analysis

BACKGROUND: We recently proposed that certain palmoplantar epidermoid cysts may be related to eccrine ducts and that human papillomavirus (HPV) 60 may play a role in their pathomechanism. However, the origin of palmoplantar epidermoid cysts is still controversial. OBJECTIVES: To examine the contribution of eccrine ducts and HPV 60 in the development of epidermoid cysts. METHODS: Five epidermoid cysts and four ridged warts that had developed on the soles of a patient were studied histologically, immunohistochemically and by DNA-DNA in situ hybridization. Using serial sections obtained from its entire body, a three-dimensional reconstruction (3DR) analysis was performed on the smallest cyst to analyse the relationship between the epidermoid cyst, eccrine duct and the overlying epidermis. RESULTS: Histological and DNA-DNA in situ hybridization analyses demonstrated both homogeneous intracytoplasmic inclusion bodies pathognomonic for HPV 60 infection and HPV 60 DNA sequences not only in all of the epidermoid cysts and ridged warts but also in the acrosyringeal portion of an eccrine duct, with the dermal portion of which the smallest cyst had been revealed to connect by 3DR analysis. However, immunohistochemical analyses using antibodies against human carcinoembryonic antigen (CEA), involucrin and several cytokeratins (CKs) revealed that the immunoreactivity of the cyst was not identical to that of the eccrine dermal duct but was identical to that of suprabasal layers of the epidermis. CONCLUSIONS: It was clearly demonstrated that an HPV 60-associated epidermoid cyst with immunoreactivities for CEA, involucrin and CKs which were identical to those of the epidermis connected with the eccrine dermal duct, supporting the idea that certain palmoplantar epidermoid cysts may develop following the epidermoid metaplasia of eccrine ducts with HPV 60 infection.     

Idiopathic plantar hidradenitis: a neutrophilic eccrine hidradenitis occurring children primarily in children

Neutrophilic eccrine hidradenitis (NEH) has been described in a variety of clinical settings but is most often seen in leukemic patients receiving chemotherapy. We have recently encountered 6 healthy individuals, of whom 5 were children, who developed NKH localized to the feel. The patients were from 9 to 21 years of age. The presenting complaint was rapid development of tenderness of the feet with varying degrees of morbidity. At clinical evaluation, tender, erythematous papules and nodules were confined to the feet, primarily the plantar surfaces. The major differential diagnoses were erythema no-dosum and vasculitis. Laboratory studies were non-contributory. Histologically, the findings were generally similar to those of NEH with certain exceptions, most notably the absence of syringosquamons metaplasia and the presence, in most cases, of neutrophilic abscesses in eccrine coils. Inflammatory and dengenerative changes involved primarily the eccrine duct (coiled and dermal), and tended to spare the secretory apparatus. Stains for microorganisms were negative. There were brief recurrences in some of the patients, but those followed over time have remained well. We suggest the term idiopnthic plantar hidradenitis for this condition.     

A case of bleomycin-induced acral erythema (AE) with eccrine squamous syringometaplasia (ESS) and summary of reports of AE with ESS in the literature

Chemotherapy-induced acral erythema (AE) is primarily induced by hydroxyurea, methotrexate, and cytarabine, although there are rare reports of AE induced by combination chemotherapy containing bleomycin. It is thought that the accumulation of chemotherapeutic drugs in eccrine glands may cause eccrine squamous syringometaplasia (ESS), which is characterized by metaplasia and focal necrosis of the epithelium of the eccrine duct. ESS is occasionally detected in conjunction with AE, but such occurrences are relatively uncommon. This is the first report of AE with ESS induced by the administration of bleomycin alone. We also provide a summary of past cases of AE with ESS in the literature.     

Mucinous syringometaplasia with prominent epithelial hyperplasia and deep dermal involvement

This report describes two patients with mucinous syringometaplasia whose findings expand the microscopic and clinical spectrum of the entity. The first patient had an eroded nodule that exhibited multiple epidermal invaginations that penetrated deeply into the dermis. In addition to mucinous metaplasia, there was also exuberant papillary epithelial hyperplasia. Expanded eccrine ducts with similar changes appeared as lobules isolated in the dermis but were shown to connect with the invaginations. In the second patient, a clinical "cyst" drained serous fluid. Multiple papillary-cystic epithelial lobules similar to those seen in the first case were located in the dermis. A few approached the epidermis, but epidermal connections were not identified. The epithelium in these lesions was identical to that previously described in mucinous syringometaplasia. The tumors differed from prior cases by virtue of the number of eccrine apparatus involved, the extent and depth of involvement, and the presence of prominent papillary epithelial hyperplasia.