Immunohistochemistry of GCDFP-24 and zinc alpha2 glycoprotein in benign sweat gland tumors

The immunohistochemical localization of two other proteins that are present in breast gross cystic disease fluid, GCDFP-24 and zinc alpha 2 glycoprotein (Zn2GP), were studied in normal skin and in 41 benign sweat gland tumors. GCDFP-24 was localized to apocrine glands. There was no staining of eccrine glands or ducts. There was positive staining in the following sweat gland tumors: apocrine hidrocystoma (four of five), hidradenoma papilliferum (two of four), syringocystadenoma papilliferum (six of seven), mixed tumor (one of one), and glandular elements of cylindroma (one of four). No staining for GCDFP-24 occurred among the following SGT: eccrine hidrocystoma (two cases), eccrine poroma (three cases), syringoma (eight cases), eccrine spiradenoma (two cases), or clear cell hidradenoma (five cases). Zn2GP was localized to both apocrine glands and eccrine glands. Positive staining was seen in the following SGT: apocrine hidrocystoma (five of five), hidradenoma papilliferum (two of four), syringocystadenoma papilliferum (four of seven), mixed tumor (one of one), cylindroma (one of four), eccrine spiradenoma (two of two), and clear cell hidradenoma (one of five). No staining for Zn2GP was seen in the following SGT: eccrine hidrocystoma (two cases), eccrine poroma (three cases), or syringoma (eight cases). GCDFP-24 appears to be a discriminant of apocrine differentiation and function. Zn2GP was expressed predominantly in tumors of apocrine differentiation. However, it was also expressed in some tumors of eccrine differentiation.     

Myoepithelial differentiation in benign sweat gland tumors

One hundred and two cases of benign sweat gland tumors of the skin were studied for the presence of myoepithelial cells specifically identified by a monoclonal antibody to alpha-smooth muscle actin on paraffin-embedded tissues. The monoclonal antibody gave a positive result in 12 of 12 cases of cylindroma, 14 of 16 cases of spiradenoma, 2 of 2 cases of apocrine tubular adenoma (papillary eccrine adenoma), 5 of 5 cases of apocrine hidrocystoma, 5 of 5 cases of hidradenoma papilliferum, and in 10 of 10 cases of syringocystadenoma papilliferum. Rare myoepithelial cells were detected in only 1 of 10 cases of mixed tumor, apocrine type. There was no immunoreactivity for alpha-smooth muscle actin in eccrine hidrocystoma (2 cases), mixed tumor of eccrine type (2 cases), syringoma (7 cases), hidroacanthoma simplex (1 case), eccrine poroma (14 cases), clear cell hidradenoma (15 cases), and in 1 case of eccrine syringofibroadenoma. Our data support the concept that myoepithelial cells are seen in most sweat gland tumors considered to differentiate toward the secretory coil of the normal sweat gland. In contrast, myoepithelial cells are absent in tumors showing differentiation toward the excretory (ductal) component of the gland.     

Immunohistochemical differentiation of extra-ocular sebaceous carcinoma from other skin cancers

We performed an immunohistochemical study using routinely processed formalin-fixed and paraffin-embedded tissue specimens from 26 cases of extra-ocular sebaceous carcinoma (EOSC) and eight easily available antibodies. They were polyclonal anti-carcinoembryonic antigen (CEA) antibody, monoclonal anti-CEA antibody, anti-breast carcinoma associated antigen-225 antibody (CU18), anti-CA15.3 antibody (CA15.3), anti-CD15 antibody (CD15), anti-breast carcinoma associated antigen antibody (B6.2), anti-gross cystic disease fluid antigen-15 antibody (GCDFP15) and anti-Thomsen-Friedenreich antigen antibody (TFA). Squamous cell carcinoma, porocarcinoma, syringomatous carcinoma, malignant clear cell hidradenoma, apocrine adenocarcinoma, and extramammary Paget's disease with underlying adenocarcinoma were used as controls. EOSC was positive for CU18 and CA15.3 in most cases, and for CD15 in a few cases. Squamous cell carcinoma of the skin was positive for CA15.3 in only one case. Porocarcinoma, syringomatous carcinoma and malignant clear cell hidradenoma were positive for CEA, CU18, CA15.3, and B6.2 in most cases. Apocrine adenocarcinoma and extramammary Paget's disease with underlying adenocarcinoma were positive for CEA, CU18, CD15, GCDFP15, CA15.3, and B6.2 in most cases. TFA was positive not only in EOSC but also in other skin cancers. Immunohistochemical examinations using these seven of eight antibodies except for TFA and routinely processed formalin-fixed and paraffin-embedded tissue specimens are beneficial in differentiating EOSC from other skin cancers.     

Immunohistochemical staining of cutaneous tumours with G-81, a monoclonal antibody to dermcidin

BACKGROUND: Recently, the novel antimicrobial peptide named dermcidin (DCD) was reported in human eccrine sweat glands. OBJECTIVES: We investigated the expression of DCD in a variety of cutaneous tumours in order to assess the usefulness of the monoclonal antibody (G-81), which recognizes a fragment of DCD. PATIENTS/METHODS: We studied the immunoreactivity of the G-81 antibody on 197 cutaneous tumours. RESULTS: A total of 13 of 26 cutaneous mixed tumours showed substantial immunoreactivity. In contrast all the following cases were completely unreactive: (i) epithelial tumours (seborrhoeic keratosis, squamous cell carcinoma, Bowen's disease, actinic keratosis, genital Paget's disease); (ii) follicular tumours (basal cell carcinoma, trichilemmoma, trichoepithelioma, trichoblastoma, keratoacanthoma, proliferating trichilemmal tumour, pilomatricoma); (iii) melanocytic tumours (malignant melanoma, naevus cell naevus, Spitz naevus, blue naevus); (iv) neural tumours (schwannoma, neurofibroma, Merkel cell neoplasm); (v) mesenchymal tumours (soft fibroma, dermatofibroma, dermatofibrosarcoma protuberans, vascular leiomyoma, leiomyosarcoma, lipoma, juvenile xanthogranuloma, angiomyoma); and (vi) other sweat gland tumours (poroid neoplasms, syringoma, cylindroma, clear cell hidradenoma, spiradenoma, syringoid eccrine carcinoma, mucinous carcinoma, apocrine cystadenoma, syringocystadenoma papilliferum, apocrine adenocarcinoma). Twenty-six cutaneous mixed tumours were considered from histopathological findings to be the apocrine type, but 13 of 26 mixed tumours contained some DCD-immunopositive cells that possibly differentiate into eccrine secretory glands. CONCLUSIONS: We found the expression of DCD in tubular structures of 50% of cutaneous mixed tumours with apocrine differentiation. These results suggest that a number of cutaneous mixed tumours show both eccrine and apocrine differentiation in the same neoplasm.     

Immunohistochemistry of gross cystic disease fluid protein (GCDFP-15) in 65 benign sweat gland tumors of the skin

Sixty-five cases of benign sweat gland tumors of the skin were studied for the expression and localization of gross cystic disease fluid protein-15 (GCDFP-15) by immunoperoxidase methods. There was positive staining of tumors of probable apocrine differentiation in 10 of 11 cases of apocrine hidrocystoma and five of five cases of hidradenoma papilliferum. There was no immunoreactivity for GCDFP-15 for tumors of probable eccrine differentiation, including five cases of eccrine hidrocystoma, five cases of eccrine poroma, five cases of eccrine spiradenoma, 10 cases of clear cell hidradenoma, and nine cases of syringoma. There was variable positive staining of tumors of more uncertain histogenesis, including eight of eight cases of syringocystadenoma papilliferum, one of four cases of cylindroma, and two of two cases of chondroid syringoma (mixed tumor). The above data support a functional differentiation of the expression of GCDFP-15 by eccrine compared to apocrine glandular epithelium with benign tumor development.     

Immunohistochemical demonstration of myoepithelial cells in sweat gland carcinomas

Although myoepithelial cells are detectable in many benign sweat gland tumours, little is known about their role in sweat gland carcinomas. To specifically demonstrate myoepithelial cells, paraffin sections from 46 sweat gland carcinomas were stained, using a standard avidin-biotin-peroxidase complex method, with the monoclonal α-smooth muscle actin antibody 1A4. Myoepithelial cells were not found in adenoid cystic eccrine carcinoma (n=2), malignant nodular hidradenoma (n=2), porocarcinoma (n=4), extramammary Paget's disease (n= 12), sclerosing sweat duct carcinoma (n=4) or in adenosquamous mucoepidermoid carcinoma (n=l). In contrast, myoepithelial cells were demonstrated in two of eight apocrine adenocarcinomas, one of six mucinous eccrine carcinomas and two of seven eccrine adenocarcinomas. In all these tumours myoepithelial differentiation was found in peripheral cells of solid tumour islands, or in basal cells of tubular structures. However, in most areas of the tumours, myoepithelial layers were discontinuous. Cells in the centre of solid tumour nodules, and luminal cells of tubular structures, were negative for α-smooth muscle actin. In analogy to breast tumours, in which malignancy and invasiveness correlate with scattered or absent myoepithelial cells, we suggest that disrupted myoepithelial layers in sweat gland carcinomas may be interpreted as a loss of the invasion barrier.     

Assessment of cellular proliferation of eccrine acrospiromas and eccrine sweat gland carcinomas by AgNOR counting and immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA) and Ki-67

Argyrophil nucleolar organizer regions (AgNORs) were counted and immunostaining using antibodies raised against proliferating cell nuclear antigen (PCNA) and Ki-67 was carried out on eccrine acrospiroma and eccrine sweat gland carcinoma, to determine the malignant potential and prognosis of these tumours. Formalin-fixed and paraffin-embedded tissue specimens surgically excised from 25 patients with eccrine sweat gland carcinoma (20 cases of eccrine porocarcinoma, four cases of ductal sweat gland carcinoma and one case of malignant clear cell hidradenoma) and 25 patients with eccrine acrospiroma (16 cases of eccrine poroma, four cases of poroid hidradenoma and five cases of clear cell hidradenoma) were used. PCNA and Ki-67 labelling indices were categorized semiquantitatively into four grades. Significant differences were noted between eccrine sweat gland carcinoma and eccrine acrospiroma with these three methods (P < 0.01). When a cut-off of 5 was chosen, the AgNOR value distinguished eccrine sweat gland carcinoma from eccrine acrospiroma with high specificity and sensitivity. Moreover, we compared the results of these three methods between stages 1 or 2 (17 cases) and stage 3 (eight cases) eccrine sweat gland carcinomas, and no significant differences were observed. From these findings, these three methods are useful in discriminating malignant from benign lesions of eccrine tumours, but have no value in estimating the aggressiveness of eccrine sweat gland carcinomas.     

Sweat gland tumors in Niger. Anatomopathology

The authors report 15 cases of sweat gland tumour observed over 2 years in Niger where their pathology was never studied. These tumours accounted for 0.38 p. 100 of all examinations performed during the same period at the pathological laboratory of the University of Niamey. They ranked sixth among the diagnoses of skin pathology. Only routine histological techniques were used. The diagnoses obtained could be divided into 5 groups. Eight women presented with partly solid cystic tumours located on the legs in 5 cases; their structure was typical of nodular hidradenoma. Two male patients had cyst-pitted tumours the superficial portion of which showed a structure of papillary eccrine adenoma, while the deep portion contained a multitude of cysts with atrophic walls; the authors consider this type of tumour as a variant of papillary eccrine adenoma. One patient had a syringocystadenoma which also included a large cyst. Finally, one patient presented with a chondroid syringoma in the axillary region, and 3 patients had histologically aggressive carcinomas located on the sole, forehead and axillary region respectively. Clinical and paraclinical investigations failed to detect any deep malignancy in these three patients, and their tumours were regarded as compatible with sweat gland carcinomas. In this series, two lesions were unusually numerous: carcinomas and nodular hydradenomas. The first named probably are a consequence of the socio-economic conditions prevailing in the population of Niger: poverty prevents patients from consulting for diseases which produce no symptoms, which artificially increases the apparent incidence of aggressive lesions. As for nodular hydradenomas, they are large owing to the presence of cysts.(ABSTRACT TRUNCATED AT 250 WORDS)     

DNA image cytometry in malignant and benign sweat gland tumours

The histopathological differentiation between well‐differentiated carcinomas and atypical adenomas of sweat gland origin may be difficult, even if immunohistochemical methods are used. Therefore, additional techniques may be helpful. We previously demonstrated that DNA image cytometry (ICM‐DNA) can be useful in distinguishing between malignant and benign clear cell hidradenoma. In the present study, a larger series of sweat gland tumours, with a clear‐cut diagnosis as malignant or benign on histopathological criteria, was examined by ICM‐DNA. Enzymatic cell separation specimens were prepared from paraffin‐embedded tissues of 18 sweat gland carcinomas (14 porocarcinomas, one classic eccrine adenocarcinoma, two microcystic adnexal carcinomas and one mostly ductal apocrine carcinoma) and 47 benign sweat gland tumours (three syringocystadenomas, five spiradenomas, 14 cylindromas, three syringomas, seven nodular hidradenomas, 10 cutaneous mixed tumours, four poromas and one apocrine hidrocystoma). Specimens were examined by ICM‐DNA according to the current recommendations of the European Society for Analytical Cellular Pathology with the AutoCyte QUIC‐DNA workstation using mesenchymal cells as an internal reference. DNA aneuploidy was detected by the stemline interpretation according to Böcking and/or at least three 5[c]‐exceeding events. DNA aneuploidy was detected in 16 of 18 (89%) of the sweat gland carcinomas, but in none of the 47 adenomas. These results suggest that the detection of DNA aneuploidy in sweat gland tumours using ICM‐DNA is a clear and specific indicator of prospective malignancy.     

Immunohistochemical study of lysozyme in various benign sweat apparatus tumors

We investigated the existence of lysozyme in various sweat apparatus tumors by adopting the avidin-biotin-peroxidase complex method. Positive reactions for lysozyme were found in four cases of apocrine cystadenoma, hidradenoma papilliferum, and an apocrine sweat apparatus benign tumor resembling "apocrine spiradenoma", all of which derive from apocrine sweat apparatus. On the other hand, in ten cases of syringoma, eccrine hidrocystoma, clear cell hidradenoma, eccrine spiradenoma, and eccrine poroma, which derive from eccrine sweat apparatus, no positive stainings for lysozyme were obtained. In four out of five cases of mixed tumor of the skin, the apocrine type exhibited positive results. Two cases of syringocystadenoma papilliferum were negative for lysozyme. The investigation of lysozyme in various sweat apparatus tumors is useful in determining the direction of differentiation in these tumors.     

Mammary and extramammary Paget's disease: expression of Ca 15-3, Ka-93, Ca 19-9 and CD44 in Paget cells and adjacent normal skin

The histogenesis of mammary Paget's disease (MPD) and extramammary Paget's disease (EMPD) cells remains controversial. The purpose of this study was to investigate MPD and EMPD immunohistochemically with antibodies to some tumour markers (Ca 15-3, KA-93 and Ca 19-9), and a cell surface receptor for hyaluronate (CD44), as these have been shown to be expressed in normal eccrine or apocrine glands and/or the epidermis, as well as some tumours. Surgically excised, formalin-fixed, paraffin-embedded tissues, or frozen tissues, from seven mammary, five vulvar, two scrolal and two axillary lesions were studied. Paget cells stained strongly with antibodies to Ca 15-3 and KA-93, but did not stain with those to Ca 19-9 and CD44. Staining with the antibody to Ca 15-3 was also observed in the ductal and secretory portions of the eccrine and apocrine glands, and in the sebaceous gland cells. Staining with the antibody to KA-93 was also seen in the apocrine secretory coils, lactiferous duct, epidermal dendritic cells, and cells in the dermal inflammatory infiltrate. Staining with the antibody to Ca 19-9 was observed only in the eccrine duct, and that to CD44 was seen in eccrine secretory cells and epidermal keratinocytes. These findings suggest that the origin of Paget cells may be the secretory cells of apocrine sweat glands (in EMPD) or the luminal lactiferous ducts (in MPD). We found that the antibodies to Ca 15-3 and CD44 were useful in differentiating Paget cells from surrounding keratinocytes, by showing positive and negative immunoreactivity, respectively.     

Cylindroma expresses immunohistochemical markers linking it to eccrine coil

Nerve growth factor, S-100 protein, CD44, and CD34 have unique expressions in or surrounding eccrine coil hut are not found in eccrine duct or apoerine gland. We studied 15 cases of cutaneous cylindroma to see if these antigens are found in this neoplasm. All were found in cylindroma to varying degrees. These results link the histogenesis of cylindroma to the eccrine coil. A unique feature of cylindroma is the large number of prominent dendritic cells most likely representing Langerhans cells that permeate the tumor aggregates.     

Immunohistochemical study of angiotensin receptors in normal human sweat glands and eccrine poroma

BACKGROUND: Angiotensin II exerts its actions through its specific receptors. However, expression of these receptors has not been determined in sweat glands. OBJECTIVES: To clarify the expression and localization of the angiotensin receptors in normal human sweat glands and eccrine poroma. METHODS: Expression of angiotensin type 1 (AT1) and type 2 (AT2) receptors in normal human eccrine and apocrine sweat glands and 12 cases of eccrine poroma was studied using immunohistochemistry. RESULTS: In eccrine sweat glands, the acrosyringium and the inner surfaces and luminal cells of the intradermal duct showed positive staining with AT1. In apocrine sweat glands, the intraepithelial duct and luminal cells of the intradermal duct showed positive staining with AT1. In 12 cases of eccrine poroma, some of the tumour cells in the tumour strands and cells surrounding the luminal structures stained positively. There were no positive findings with AT2. CONCLUSIONS: Studying AT1 distribution may be useful in understanding the pathophysiology of sweat glands and sweat gland tumours.     

Expression of differentiation antigens in benign sweat gland tumours

Fifty benign sweat gland tumours were studied for the expression of carcinoembryonic antigen (CEA) and apocrine epithelial antigen (AEA), using immunohistochemical methods. CEA was found in thirty-two and AEA in thirty-three neoplasms. Both antigens were located in the epithelium of the luminal structures and in the intraluminar material and CEA was occasionally found also in proliferating cells. Co-expression of CEA and AEA occurred frequently in cases of syringoma, syringocystadenoma papilliferum, hidradenoma papilliferum, eccrine spiradenoma and clear cell hidradenoma. AEA was seen also in tumours showing eccrine differentiation, even though it is not present in normal eccrine sweat ducts.     

An Immunohistochemical Study of BCA-225 in Various Skin Cancers

We performed an immunohistochemical study of BCA-225, which is a glycoprotein secreted by the T47D breast carcinoma cell line and recognized by monoclonal antibody BRST-1 (clone name: CU-18), in normal skin and various skin cancers. In normal skin, BCA-225 was positive only in the secretory portion of both eccrine and apocrine glands and in mature cells of the sebaceous gland. We observed 10 cases of squamous cell carcinoma of the skin, 10 cases of basal cell carcinoma without sebaceous differentiation, 3 cases of basal cell carcinoma with sebaceous differentiation, 6 cases of malignant trichilemmoma, 8 cases of eccrine porocarcinoma, 3 cases of ductal carcinoma, 1 case of malignant clear cell hidradenoma, 1 case of apocrine adenocarcinoma, 6 cases of extra-ocular sebaceous carcinoma, 5 cases of extramammary Paget's disease with underlying adenocarcinoma, and 11 cases of extramammary Paget's disease without underlying adenocarcinoma. Most of the cases of sweat gland carcinoma, basal cell carcinoma with sebaceous differentiation, sebaceous carcinoma, and extramammary Paget's disease were positive for BCA-225, while none of the cases of squamous cell carcinoma, basal cell carcinoma without sebaceous differentiation, or malignant trichilemoma were positive. Based on these findings, we believe that BCA-225 is useful in distinguishing tumors with sweat gland and sebaceous differentiation and extramammary Paget's disease from tumors without such differentiation.     

Giant clear cell hidradenoma of the knee

Hidradenomas, also referred to as nodular hidradenomas or clear cell hidradenomas (CCH), are benign cutaneous eccrine tumors usually 2–3 cm in dimension. Hidradenomas are relatively common; however, giant forms are rare. We report a case of an 8.0 × 6.0 × 3.0 cm clear cell hidradenoma of the left knee in a 43‐year‐old man. The tumor was mobile, located above the patellar tendon and was without bony involvement on imaging studies. Grossly, the resected tumor was unencapsulated and tan, with a solid and cystic cut surface showing papillary excrescences on the cyst wall. Microscopically, the tumor cells showed an infiltrative growth pattern at the periphery, however, the tumor cytology was bland and no necrosis or mitoses were identified. The overlying dermis contained hemosiderin pigment deposition and infiltration with eosinophils. Immunohistochemically, tumor cells were positive for cytokeratin, CAM5.2, p53, carcino‐embryonic antigen (CEA) and epithelial membrane antigen (EMA), and negative for CD10 and Ki‐67. The cytological features of hidradenomas can present diagnostic challenges, as other ‘clear cell’ tumors such as metastatic renal cell carcinoma should be considered. Immunohistochemical studies and differential diagnoses are discussed. Yu G, Goodloe S, D’Angelis CA, McGrath BE, Chen F. Giant clear cell hidradenoma of the knee.     

An Immunohistochemical Study of Sebaceous Carcinoma with Anti-Keratin Monoclonal Antibodies: Comparison with Other Skin Cancers

Formalin-fixed and paraffin-embedded tissue specimens of six cases of extraocular sebaceous carcinoma were studied immunohistochemically with eight anti-keratin monoclonal antibodies, 34βB4, 35βH11, Ks13.1, Ks19.1, PKK1, LP34, KL1 and AE1. The staining patterns of sebaceous carcinoma were compared with those of normal sebaceous glands and other skin cancers which should be distinguished from sebaceous carcinoma histopathologically. The other skin cancers compared were eccrine porocarcinoma, malignant clear cell hidradenoma, extramammary Paget's disease with underlying adenocarcinoma, malignant trichilemmoma, and squamous cell carcinoma. Most cases of sebaceous carcinoma were stained with 35βH11, Ks19.1, LP34, KL1 and AE1, while normal sebaceous glands were positive only with 35βH11, LP34, KL1 and AE1. By immunostaining, sebaceous carcinoma was distinguishable from extramammary Paget's disease with underlying adenocarcinoma, squamous cell carcinoma, malignant trichilemmoma, and eccrine porocarcinoma, but was not clearly distinguishable from malignant clear cell hidradenoma. These findings demonstrate that sebaceous carcinoma shows positive reactions with antibodies to simple epithelial keratin, probably as a result of neoplastic transformation, and that immunohistochemical examination using anti-keratin monoclonal antibodies is useful in distinguishing sebaceous carcinoma from several other skin cancers.     

Coexpression of cytokeratin and vimentin intermediate filaments in benign and malignant sweat gland tumors

The coexpression of cytokeratin and vimentin intermediate filaments has been immunohistochemically evaluated in 124 benign and malignant sweat gland tumors of various types in comparison to normal sweat glands. In addition, all neoplasms have been stained by an antibody to alpha-smooth muscle actin. Epithelial cells reacted with the pan-cytokeratin antibody lu-5. In normal sweat glands, vimentin immunoreactivity was restricted to myoepithelial cells and to some cells of the coiled duct. In benign sweat gland tumors (n=88), coexpression of vimentin and alpha-smooth muscle actin was frequently found in basal cells of neoplasms considered to differentiate towards the secretory coil of the eccrine or apocrine gland. These included eccrine spiradenoma, apocrine cystadenoma, hidradenoma papilliferum, syringocystadenoma papilliferum, and cylindroma. Thus, in these tumors, vimentin-reactive cells corresponded to myoepithelial cells. Vimentin-positive cells were also found in 14 of 36 sweat gland carcinomas, including 1 case of sclerosing sweat duct carcinoma, 1 case of porocarcinoma, 4 cases of eccrine adenocarcinoma, 1 case of mucinous eccrine carcinoma, and 5 cases of apocrine adenocarcinoma. Co-expression of vimentin and alpha-smooth muscle actin was observed in some cells of eccrine and apocrine adenocarcino-mas. Therefore, in these neoplasms, some vimentin-positive cells appear to represent myoepithelial cells. In contrast, vimentin-positive cells in all other malignant tumors did not express alpha-smooth muscle actin. Our results indicate that coexpression of cytokeratin and vimentin may be frequently found in a variety of benign and malignant sweat gland tumors. In the majority of these neoplasms, vimentin-positive cells correspond to myoepithelial cells. Because vimentin is not specific for myoepithelial cells, additional stains for alpha-smooth muscle actin should be performed to prove the myoepithelial nature of vimentin-positive cells.     

Pedigree of multiple benign adnexal tumours of Brooke-Spiegler type

A pedigree of autosomal dominant expression of multiple benign adnexal tumours is presented. Seven cases spanning three generations are discussed. The clinical manifestations of these tumours are quite variable, including multiple papules concentrated on the face, scalp nodules and a large turban tumour. One member of the family had a linear papular eruption involving one half of his body. Histopathology of all lesions demonstrated benign adnexal characteristics, including well-characterized eccrine spiradenomas, trichoepitheliomas and an eccrine cylindroma. The cutaneous tumours occurring in these patients have continued to develop during their lifetimes. The authors propose that this pedigree has phenotypic characteristics consistent with Brooke-Spiegler syndrome.     

Nodular hidradenoma arising on the site of a BCG scar

Hidradenomas are tumours that arise from the adnexal structures, both eccrine and apocrine and are histologically benign. The tumours that arise from eccrine differentiation are known as poroid hidradenomas and when they arise from the apocrine glands they are called nodular hidradenomas. In our centre a 13‐year‐old boy presented with a slow‐growing, painless erythematous fungating nodule on the left upper arm over a period of 18 months at the site of the BCG vaccination. The nodule was surgically excised and sent for histopathological examination, leading to a diagnosis of nodular hidradenoma. This case is presented to highlight its rarity, together with its clinical features that were suggestive of malignancy but proved ultimately to be benign.