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Abstract: Cuticular poroma is a rare variant of poroma composed of exclusively or predominantly cuticular cells, namely of large cells with ample eosinophilic cytoplasm. We report 7 cases of this rare tumor identified among 426 neoplasms diagnosed as poroma or porocarcinoma. The patients were 4 males and 3 females, ranging in age from 18 to 88 years. All presented with a solitary asymptomatic nodule. The location included knee (2 cases), shoulder, thigh, shin, lower arm, and neck (each 1). All lesions were surgically removed. No evidence of disease was observed in 5 patients with available follow-up (range 12-124 months).Microscopically, all neoplasms were composed of variably sized, focally closed packed, or interconnecting nodules constituted mostly of cuticular cells. Small poroid cells were a focal feature in 5 tumors, whereas in the remaining 2 cases, poroid cells with conspicuous but still in minority. Five neoplasms were somewhat asymmetric, with irregular outlines. Ductal differentiation and intracytoplasmic vacuoles were seen in 6 tumors. Other features variably encountered were conspicuous intranuclear pseudoinclusions, cystic change, occasional multinucleated cells, increased mitoses, and stromal desmoplasia. Four of the 5 tumors analyzed with next-generation sequencing yielded YAP1::NUTM1 fusions. In addition, various mutations, mostly of unknown significance were identified in one neoplasm., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Spitz tumors are melanocytic neoplasms characterized by specific, mutually exclusive driver molecular events, namely genomic rearrangements involving the threonine kinase BRAF and the tyrosine kinase receptors ALK , NTRK1 , NTRK2 , NTRK3 , MET , RET , ROS1 , and MAP3K8 or less commonly, mutations in HRAS or MAP2K1 . We hereby report 5 Spitz tumors with a SQSTM1::NTRK2 fusion. All patients were woman with the ages at diagnosis ranging from 30 to 50 years. Locations included the lower extremity (n = 3), forearm, and back (one each). All the neoplasms were superficial melanocytic proliferation with a flat to dome-shaped silhouette, in which junctional spindled and polygonal dendritic melanocytes were mainly arranged as horizontal nests associated with conspicuous lentiginous involvement of the follicular epithelium. Only one case showed heavily pigmented, vertically oriented melanocytic nests resembling Reed nevus. A superficial intradermal component observed in 2 cases appeared as small nests with a back-to-back configuration. In all lesions, next-generation sequencing analysis identified a SQSTM1::NTRK2 fusion. A single case studied with fluorescence in situ hybridization for copy number changes in melanoma-related genes proved negative. No further molecular alterations were detected, including TERT-p hotspot mutations., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

ALK-fused spitzoid neoplasms represent a distinctive group of melanocytic lesions. To date, few studies addressed genetic and chromosomal alterations in these lesions beyond the ALK rearrangements. Our objective was to study genetic alterations, including ALK gene fusions, telomerase reverse transcriptase promoter (TERT-p) mutations, chromosomal copy number changes, and mutations in other genes. We investigated 29 cases of Spitz lesions (11 Spitz nevi and 18 atypical Spitz tumors), all of which were ALK immunopositive. There were 16 female and 13 male patients, with age ranging from 1 to 43 years (mean, 18.4 years). The most common location was the lower extremity. Microscopically, all neoplasms were polypoid or dome shaped with a plexiform, predominantly dermally located proliferation of fusiform to spindled melanocytes with mild to moderate pleomorphism. The break-apart test for ALK was positive in 17 of 19 studied cases. ALK fusions were detected in 23 of 26 analyzable cases by Archer FusionPlex Solid Tumor Kit. In addition to the previously described rearrangements, 3 novel fusions, namely, KANK1-ALK, MYO5A-ALK, and EEF2-ALK, were found. Fluorescence in situ hybridization for copy number changes yielded one case with the loss of RREB1 among 21 studied cases. TERT-p hotspot mutation was found in 1 of 23 lesions. The mutation analysis of 271 cancer-related genes using Human Comprehensive Cancer Panel was performed in 4 cases and identified in each case mutations in several genes with unknown significance, except for a pathogenic variant in the BLM gene. Our study confirms that most ALK fusion spitzoid neoplasms can be classified as atypical Spitz tumors, which occurs in young patients with acral predilection and extends the spectrum of ALK fusions in spitzoid lesions, including 3 hitherto unreported fusions. TERT-p mutations and chromosomal copy number changes involving 6p25 (RRB1), 11q13 (CCND1), 6p23 (MYB), 9p21 (CDKN2A), and 8q24 (MYC) are rare in these lesions. The significance of mutation in other genes remains unknown.

Previous studies showed that ALK is often positive in epithelioid fibrous histiocytoma (EFH). Two cases of EFH with ALK gene fusions have been recorded. Our objective was to study a series of EFH to present histopathological variations of EFH, identify novel ALK gene fusions, and determine whether there is a correlation between histopathological features and particular gene. We investigated 14 cases of EFH, all ALK immunopositive. The cases were assessed histopathologically as well as for ALK and TFE-3 rearrangements using FISH and ALK gene fusions using next-generation sequencing. The analysis of the sequencing results was performed using the Archer Analysis software (v5; ArcherDX Inc). The study group consisted of 8 female and 6 male patients, ranging in age from 18 to 79 years (mean 42 years; median 37.5 years). All presented with a solitary lesion. Microscopically, most lesions were polypoid and composed of epithelioid cells with ample cytoplasm. In addition, a variable number of bi-, tri-, or multinucleated, spindled, multilobated, cells with eccentric nuclei, cells with nuclear pseudoinclusions, mucinous, and grooved cells were admixed. In 5 cases, the predominant epithelioid cell component consisted of rather small cells, whereas spindled cells dominated in 3 cases. Of these, 2 lesions were composed rather of pale eosinophilic to clear cells, occasioning a resemblance to PEComa or leiomyoma. Immunohistochemically, all cases expressed ALK and 11 were positive for TFE-3. The break apart test for ALK was positive in 11 cases, whereas specimens from the remaining 3 cases were not analyzable. ALK genes fusions were found in all but 3 cases and included SQSTM1-ALK (3), VCL-ALK (3), TMP3-ALK (2), PRKAR2A-ALK (1), MLPH-ALK (1), and EML4-ALK (1). No correlation between histological features and type of ALK fusion was found. TFE-3 break apart test was negative. It is concluded that ALK-immunopositive EFH shows ALK gene fusions that involve various protein-coding genes, implicated in a variety of biological processes. Rare variants of EFH rather consist of spindled "non-epithelioid" cells.

Adenoid cystic carcinoma (ACC) of the skin is a rare malignant neoplasm histologically identical to homonymous tumors in other organs. Cutaneous ACC has been found to harbor MYB gene activations, either through MYB chromosomal abnormalities or by generation of the MYB-NFIB fusion. In salivary gland ACC, in addition to the MYB gene, alterations in MYBL1, the gene closely related to MYB, have been reported. We studied 10 cases of cutaneous ACC (6 women, 4 men; and age range 51-83 years) for alterations in the MYB, NFIB, and MYBL1 genes, using FISH and PCR. MYB break-apart and NFIB break-apart tests were positive in 4 and 5 cases, respectively. MYB-NFIB fusions were found in 4 cases. The break of MYBL1 was found in 2 cases, and in one of them, the NFIB break-apart probe was positive, strongly indicating a MYBL1-NFIB fusion. In 2 cases, the MYB break-apart test was positive, whereas no MYB-NFIB was detected, strongly suggesting another fusion partner. It is concluded that MYBL1 alterations are detected in primary cutaneous ACC but are apparently less common compared with MYB and NFIB alterations.

Brooke-Spiegler syndrome (BSS) and its phenotypic variants, multiple familial trichoepithelioma (MFT) and familial cylindromatosis, are rare autosomal dominant hereditary diseases. They are characterized by the presence of multiple adnexal tumors, especially cylindromas, spiradenomas, spiradenocylindromas, and trichoepitheliomas. Implicated in the pathogenesis of the disease is the gene CYLD, which is localized on the long arm of chromosome 16. This gene encodes an evolutionarily conserved protein belonging to the deubiquitinating enzymes family, which plays a key role in many signaling pathways, especially in NF-κB, JNK, and Wnt. Less than 90 germline mutations of CYLD have been identified in patients with BSS/MFT. These mutations are mostly small alterations in the coding sequence and at exon-intron junction sites. One patient with an intronic mutation and another with a large CYLD deletion have also been recorded. In this study, the authors have analyzed a cohort of 14 patients with BSS/MFT from 13 families for large genome rearrangements by array comparative genome hybridization followed by confirmatory sequencing. We identified 2 large deletions, namely c.-34111_*297858del378779 and c.914-6398_1769del13642ins20 in patients with MFT and BSS, respectively. All other analyzable patients did not reveal any copy number alteration. It is concluded that the large rearrangements are relatively rare in patients without a germline CYLD mutation demonstrable by conventional sequencing. The pathogenetic mechanisms in patients with BSS/MFT lacking germline sequence alterations or large rearrangements in the CYLD gene remain to be clarified.

Brooke-Spiegler syndrome (BSS) is a rare, inherited, autosomal dominant disorder characterized by development of multiple adnexal cutaneous neoplasms including spiradenoma, cylindroma, spiradenocylindroma, and trichoepithelioma. The syndrome of multiple familial trichoepitheliomas (MFT) is considered a phenotypic variant of BSS in which patients present with trichoepitheliomas only. We studied germline and somatic mutations of the CYLD gene by direct sequencing in patients with BSS (n = 49) and MFT (n = 18) using peripheral blood and 90 samples of frozen or formalin-fixed paraffin-embedded tumor tissue selected from 379 available histology specimens. Germline CYLD mutations were found in 51 patients (76%) from 36 families (75%). Germline CYLD mutations were found in 43 of the 49 patients with BSS (88%) but in only 8 of 18 MFT cohort (44%). Twenty-one frameshift, 15 nonsense, 3 missense, and 4 splice site mutations were found in patients with BSS, whereas 1 frameshift, 5 nonsense, and 2 splice site mutations were identified in the MFT cohort. Five novel mutations were identified including 4 frameshift mutations (c.1027dupA/p.T343NfsX7, c.2155dupA/p.M719NfsX5, c.2288_2289delTT/p.F763X, and c.2641delG/p.D881TfsX32) and 1 nonsense mutation (c.2713C>T/p. Q905X). Of the 76 tumors from 32 patients with a germline CYLD mutation, 12 were spiradenomas, 15 spiradenocylindromas, 26 cylindromas, 15 trichoepitheliomas, and 7 were other tumor types. Somatic mutations were detected in 67 specimens of these 76 tumors (88%). Of the 67 somatic mutations, 21 (31%) represented a sequence alteration and 46 (69%) showed loss of heterozygosity. In the remaining 9 cases (12%), the somatic changes remained unknown. A germline CYLD mutation was not detected in 14 tumor samples from 8 patients. In these 14 tumors, somatic mutations were identified in 6 samples (43%), all consisting of sequence alterations (1 sample showed 2 different sequence alterations). In the remaining 8 samples (53%), neither germline nor somatic mutations were found in the lesional tissue. Our study increases the catalog of known CYLD mutations in patients with BSS/MFT to 86 and documents the variability of somatic mutations that may occur in them. We confirm the absence of firm genotype-phenotype correlations and the existence of a subset of patients with BSS/MFT who lack a demonstrable germline CYLD mutation. Further studies are needed to explain the reasons for this phenomenon.

We report 11 individuals, each presenting with few (2-4) adnexal neoplasms histologically confirmed as belonging to the spectrum of lesions typical for Brooke-Spiegler syndrome (BSS) and/or multiple familial trichoepitheliomas. These include spiradenoma, cylindroma, spiradenocylindroma, and trichoblastoma variants. Our objective was to clarify whether this is merely a sporadic, albeit unusual, occurrence of multiple neoplasms in these patients or whether they are related to BSS and its phenotypic variant, multiple familial trichoepithelioma. Six patients presented with 2 neoplasms, 4 had 3 lesions and the last had 4 lesions. In none was there any family history of similar lesions. The 28 neoplasms consisted of 7 spiradenomas, 6 cylindromas, 5 spiradenocylindromas, and 11 trichoblastomas (6 trichoepitheliomas and 5 with mixed patterns). In 1 patient only with 2 spiradenomas, both tumors harbored identical CYLD sequence alterations (c.1112C>A/S371X) in the CYLD gene and both showed loss of heterozygosity on chromosome 16q. The remaining cases yielded neither germ line nor somatic alterations in CYLD. It is concluded that the presentation with few (2-4) cylindromas, spiradenomas, spiradenocylindromas, and trichoepitheliomas is a sporadic occurrence, and that these patients do not have any relationship to BSS.

Multiple familial trichoepitheliomas (MFT) constitute an autosomally inherited syndrome possibly related to Brooke-Spiegler syndrome (BSS). Although some early studies suggested a role for the PTCH gene on chromosome 9q22.3 in the etiopathogenesis of MFT, recent studies of occasional patients with the MFT clinical phenotype identified mutations in the CYLD gene on chromosome 16q12-q13, a gene responsible for BSS. A systematic investigation of PTCH and CYLD mutations in patients with MFT has never been performed. Our main objective was to collect a reasonably large series of patients with MFT to (1) study the clinicopathological spectrum of the disease, (2) determine whether the PTCH gene is implicated in the pathogenesis of MFT, and if so (3) determine the relative frequency of CYLD and PTCH mutations, (4) establish if there may be any possible genotype-phenotype correlations, and (5) study the spectrum of somatic mutations. Clinical analysis including family histories, histopathological investigations, and molecular genetic studies were performed. There were 9 female and 7 male patients ranging in age from 11 to 63 years. They presented with multiple, small, discrete and sometimes confluent, skin-colored to pink, asymptomatic nodules preferentially located on the face, being especially prominent and confluent in the nasolabial folds and inner aspects of the eyebrows. A total of 66 conventional trichoepitheliomas (TEs) were studied microscopically. Aside from typical features of TE, some also exhibited variant morphological patterns including areas reminiscent of other benign adnexal neoplasms and melanocytic hyperplasia. In none of the 9 patients tested was a germline mutation of the PTCH gene identified. Germline CYLD mutations were detected in 6 of 13 patients tested (identical in 2 unrelated patients) including 2 novel mutations, whereas the remaining 7 individuals showed wild-type alleles. Two patients with germline wild-type CYLD showed, however, a somatic mutation in the gene (1 duplication, 1 substitution mutation). Neither CYLD nor PTCH germline mutations were found in the 5 patients in whom both genes were analyzed. MFT seems to be a phenotypic variant of BSS. The PTCH gene is rarely, if ever, involved in the pathogenesis of MFT. Absence of a germline mutation of the CYLD gene in cases harboring a somatic mutation may be explained by large deletions in the gene or by mutation in intronic sequences or in the promoter region. Considering our 5 patients with no mutation in either gene, the final possibility is that another, as yet undescribed gene (neither CYLD nor PTCH) is implicated in the pathogenesis of some patients with MFT.

We performed immunohistochemical assessment of p53 expression and TP53 mutational analysis of 15 malignant neoplasms arising from preexisting benign cylindroma, spiradenoma, and spiradenocylindroma, sporadic or associated with Brooke-Spiegler syndrome. At least weak and focal p53 positivity was present in 13 of the 15 lesions. Successful PCR and sequencing were possible in 12 of the 15 cases. In one case only there were 2 p53 mutations, one being a c.673-1G>A splice-site mutation in the 3'-end of intron 6 (position--g.15289G>A, contig gb.AY838696.1) and the second being a c.743G>A (p.R248Q) mutation in exon 7 (position--15360G>A, contig gb.AY838696.1). Single nucleotide polymorphisms were detected in all 12 malignant cases analyzed. As a control group, we included 12 randomly selected sporadic cases of spiradenoma (n = 5), cylindroma (n = 4), and spiradenocylindroma (n = 3). None of the 12 benign control group cases harbored a TP53 mutation, whereas all 12 demonstrated single nucleotide polymorphisms identical to those detected in the malignant tumor group. Immunohistochemically, 1 cylindroma and 2 spiradenomas demonstrated weak and focal p53 positivity. In conclusion, we found a fairly high rate of p53 expression in malignant neoplasms arising from preexisting benign spiradenomas, cylindromas, and spiradenocylindromas. However, the mutation rate of TP53 was low. Whereas immunostaining for p53 has been suggested as an adjunct tool to differentiate benign spiradenoma, cylindroma, and spiradenocylindroma from their malignant counterparts, its utility is limited by its heterogeneous pattern of expression, especially the sometimes lack of staining in clearly malignant areas and the occurrence of focal, weak positivity in the benign residua or in unequivocally benign neoplasms.

We report a patient with multiple trichoepitheliomas whose biopsy material also demonstrated a range of other neoplasms with follicular differentiation, including small nodular trichoblastoma, small nodular basal cell carcinoma (BCC), and areas resembling infundibulocystic BCC/basaloid follicular hamartoma. These were all intimately associated with otherwise typical trichoepitheliomas that dominated the microscopic appearances. Peripheral blood and tumor tissues of the patient and his 2 daughters, who apparently had a milder phenotype, were studied for alterations in the CYLD and PTCH genes, but mutations or loss of heterozygosity was not found in either gene. The occurrence of multiple follicular neoplasms within a single lesion adds evidence that, although in most cases BCC and trichoblastoma are distinct lesions, the 2 neoplasms do encompass a morphological spectrum of follicular differentiation, which is probably more overtly expressed in syndromic patients.

We present a case of Brooke-Spiegler syndrome with a germline deep intronic mutation in the CYLD gene leading to intronic exonization. Additionally, diverse somatic mutations were identified, namely loss of heterozygosity, a recurrent nonsense mutation, and a sequence mutation causing exon skipping. These somatic aberrations were identified in 4 different cylindromas that had been removed from the patient. Additionally, we microscopically studied a spiradenocylindroma that showed unusual histology, including foci of follicular differentiation. A deep intronic mutation resulting in exonization and a somatic sequence mutations causing exon skipping are hitherto unreported genetic mechanisms involving the CYLD gene in patients with Brooke-Spiegler syndrome.

The association of tuberous sclerosis complex (TSC) and autosomal dominant polycystic kidney disease (ADPKD), termed TSC2/PKD1 contiguous gene syndrome, is a result of molecular defect demonstrating by deletion disrupting TSC2 and PKD1. Dermatopathology of this syndrome has never been addressed. We report 2 sporadic cases form of TSC2/PKD1 contiguous gene syndrome, with emphasis on dermatopathologic findings. Both patients presented with a typical phenotype of TSC and early-onset renal polycystic requiring kidney transplantation in one of the patients. Of a total of 13 cutaneous lesions studied, there were 7 facial angiofibromas, 2 shagreen patches, 1 periungual fibroma, 1 hypopigmented macule, 1 epidermoid cyst, and 1 intradermal melanocytic nevus. The histological features were basically similar to those occurring in TSC, but some unusual features were identified. In both patients, deletions in the region of TSC2 and PKD1 were revealed performing by multiplex ligation probe amplification test. It is concluded that the histopathological features of skin lesions in this syndrome are similar to those encountered in TSC. Clinical awareness and appropriate molecular investigation of TSC2/PKD1 contiguous gene syndrome is necessary in all patients with a typical phenotype of TSC in infancy, adolescence, or adult age, because of severity of the renal alterations.

We present a case of primary cutaneous diffuse large B-cell lymphoma, leg type, with an unusual clinical picture. A 41-year-old man presented with a 2-year history of slowly progressive plaques, nodules, and garland-like patches on his chest, right upper arm, and back. Complete staging investigations revealed no extracutaneous involvement. Histological examination of a nodule revealed a diffuse nonepidermotropic infiltrate mainly composed of large blast cells with features of immunoblasts and centroblasts and spindle cells seen at the periphery of the infiltrate. Histological examination of a garland-like lesion showed perivascular infiltrates composed predominantly of small lymphocytes admixed with only occasional large blasts. The blasts from the nodule and garland-like lesions and spindle cells identified in the nodule exhibited an identical phenotype: they stained positively for CD20, CD79a, and bcl-2 and tested negative for bcl-6, CD5, CD10, and TdT. CD35 revealed no networks of follicular dendritic cells. Widespread garland-like lesions are not a typical feature of primary cutaneous diffuse large B-cell lymphoma.

We present a series of 14 cases of cutaneous hidradenocarcinomas. The patients included 6 women and 8 men ranging in age at diagnosis from 34 to 93 years. All but 1 patient presented with a solitary nodule. There was no predilection site. One patient presented with multiple lesions representing metastatic nodules. Of 12 patients with available follow-up, 2 died of disease, whereas the remaining 10 patients were alive but 3 of them experienced a local recurrence in the course of the disease. Grossly, the tumors ranged in size from 1.2 to 6 cm. Microscopically, of the 14 primary tumors, 9 showed low-grade cytomorphology, whereas the remaining 5 neoplasms were high-grade lesions. The residuum of a hidradenoma was present in 5 of the 14 primaries. The mitotic rate was highly variable, ranging from 2 to 64 mitoses per 10 high-power field. The cellular composition of the tumors varied slightly, with clear cells, epidermoid cells, and transitional forms being present in each case. In 1 case, there was metaplastic transformation into sarcomatoid carcinoma. Glandular differentiation varied from case to case and appeared most commonly as simple round glands or as cells with intracytoplasmic lumens. Necrosis en masse was detected in 8 specimens. One specimen represented a reexcision and was unusual as it showed a well-demarcated intradermal proliferation of relatively bland clear cells accompanied by an overlying intraepidermal growth of clear cells resembling hidradenoacanthoma simplex. Despite the bland appearance, the tumor metastasized to a lymph node. Immunohistochemically, 5 of the 8 specimens studied for Her2/neu expression were negative, whereas 3 specimens from 2 cases yielded score +2, but all the 3 specimens with score 2+ subsequently proved negative for Her2/neu gene amplification by fluorescence in situ hybridization. Of 10 primaries studied, 4 tumors showed positive p53 immunoreaction in more than 25% of the cells comprising the malignant portion of the lesions, in 2 cases, a minority of the neoplastic cells (10%-20%) demonstrated nuclear staining, whereas the remaining 4 cases were negative. Of 9 specimens of hidradenocarcinoma studied for TP53 mutations, 2 harbored mutations, whereas the remaining 7 specimens showed the wild-type sequence. Of 11 specimens studied for translocation t(11;19), 2 cases harbored the translocation. It is concluded that cutaneous hidradenocarcinomas show some microscopic heterogeneity and comprise both low- and high-grade lesions that cytologically are similar to their benign counterpart, the hidradenoma. Within the spectrum of low-grade lesions, there seem to exist tumors almost indistinguishable from hidradenomas but still being capable of regional or distant metastasis. Similar to hidradenomas, hidradenocarcinomas show a t(11;19) translocation, but it is a significantly rarer event. Even rarer is the amplification of the Her2/neu gene. Of note is the relatively low frequency of TP53 mutations despite a high rate of p53 protein expression at the immunohistochemical level.

Alveolar soft-part sarcoma (ASPS) is a rare distinctive sarcoma, in most cases involving deep soft tissues of the extremities. It is associated with a specific unbalanced translocation, der(17)t(X;17)(p11;q25) that results in the formation of an ASPL-TFE3 fusion gene. Microscopically, it is typified by an alveolar growth of large cells containing typical periodic acid-Schiff-positive rod-shaped crystals, often serving as a diagnostic clue. Other distinctive features include nuclear immunoreactivity for transcription factor 3 (TFE3) protein and a typical ultrastructural finding of large crystals with a rectangular or rhomboid shape. The authors present an unusual case of ASPS with cutaneous involvement, which did not exhibit typical large crystals; there were striking round granules. Molecular genetic study revealed fusion transcript ASPL-TFE3, type 2. To the best of our knowledge, cutaneous involvement of a crystal-deficient ASPS has not been reported.

Previous studies suggested that mutant beta-catenin gene cells in cutaneous adnexal tumors with matrical differentiation contribute to their tumorigenesis. Except for pilomatricoma and pilomatrical carcinoma, only a handful of other cutaneous adnexal tumor types have been studied. DNA was extracted from 86 lesions including 17 proliferating tricholemmal and trichilemmal tumors, 15 trichoblastomas, 7 trichoadenomas, 4 pilomatricomas, 1 pilomatrical carcinoma, 4 basal cell carcinomas (BCCs) with shadow cells, 2 trichofolliculomas, 3 BCCs with sebaceous differentiation, 9 sebaceous adenomas, 6 sebaceomas, 14 sebaceous carcinomas (both ocular and extraocular forms), 2 gigantic horns, and 2 apocrine mixed tumors with shadow cells and subjected to polymerase chain reaction with newly designed primers encompassing glycogen synthase kinase-3beta phosphorylation sites of the CTNNB1 gene. Also, 3 craniopharyngiomas were studied. Sequenced polymerase chain reaction products for possible beta-catenin gene mutations showed a total of 8 alterations. These included 5 different point mutations, 3 of them identified in 2 different tumors: S23N (cribriform trichoblastoma), D32Y (pilomatricoma and craniopharyngioma), G34R (pilomatrical carcinoma and craniopharyngioma), S37F (2 BCCs with shadow cell differentiation), and G34V (craniopharyngioma). This study broadens the list of cutaneous adnexal tumors harboring CTNNB1 mutations and extends the listing of the mutations occurring in these neoplasms.

The authors report a case of basaloid carcinoma involving the anus and rectum of a 57-year-old woman. Microscopically, the tumor showed unusual morphologic features strongly resembling a spiradenocylindroma because it consisted, in most parts, of basaloid cell nodules arranged in a jigsaw-puzzle fashion containing or surrounded by eosinophilic basal membrane material; in addition, there were intratumoral lymphocytes. The overlying squamous epithelium manifested dysplastic changes compatible with in situ squamous carcinoma that gradually became invasive and blended with basaloid cell islands; additionally, there were koilocytes in the squamous epithelium. A molecular biology study identified HPV-16 in the lesional tissue. Analysis of the CYLD gene did not prove any mutation.

Skin adnexal type tumors situated in the parenchyma of the breast are very rare. We report herein a case of solid-cystic hidradenoma of the breast. The tumor was situated in the parenchyma of the breast of a 55-year-old female and showed no connection to the overlying skin on ultrasound and radiology investigations, grossly and microscopically. Histologically, the tumor was identical to its cutaneous counterpart and was surrounded by breast tissue. The neoplasm was composed of solid and cystic areas. The cystic component, which predominated in the lesion, was filled with homogeneous eosinophilic material. The solid component consisted of several nodules with vague lobulated architecture protruding into the cystic spaces. The nodules were composed of cuboidal monomorphous cells that were continuous with larger polygonal cells and rare, large mucinous cells with basophilic granular cytoplasm. Several mammary ducts in close proximity to the tumor showed features of columnar cell hyperplasia. A 120-bp METC1/MAML2 fusion transcript was identified by RT-PCR and subsequent sequencing technique. This t(11;19) translocation has been reported in approximately 50% of hidradenomas of the skin.

The authors report two examples of nodular hyperplasia of the Bartholin gland. Each occurred in the vulva, close to the introitus of women aged 33 and 49 years, who presented with slightly painful lesions that were clinically thought to be cysts. Grossly, both masses exhibited a multilobular architecture, were elastic, were gray in color, and measured 4 cm and 3.2 cm in greatest dimension. On microscopic examination, the lesions looked similar and exhibited an increased number of secretory acini, with maintenance of the normal duct-acinar relationship--features compatible with nodular hyperplasia. Rare dilated ducts were observed, and intraluminal inspissated secretions were occasionally seen. In one case, there were a focal mild inflammatory infiltrate, squamous metaplasia of larger ducts, and rare ruptured ducts with extravasated stromal mucin. Clonality analysis performed in one case revealed a monoclonal pattern, suggesting that the lesion may be a neoplastic process rather than simple reactive hyperplasia.

We present a series of 15 cases of cutaneous lymphoma and pseudolymphoma with dual lineage rearrangement identified among approximately 1200 cases of cutaneous lymphoproliferative disorders assessed in our 4 institutions during the last 8 years in which the results of both T-cell receptor and immunoglobulin heavy chain rearrangement investigations were available. On the basis of the clinicopathologic information, the cases were retrospectively subdivided into 2 categories: (1) cases with definite features of cutaneous lymphoma or pseudolymphoma (n = 11) and (2) cases with unclassifiable disease (n = 4). The detection of dual genotype in the first group did not influence the final diagnosis; 7 cases represented cutaneous B-cell lymphomas, 3 pseudolymphomas, and 1 case lymphomatoid papulosis. The presence of monoclonal T-cell receptor-gene rearrangements in these cases may be explained either by monoclonal or oligoclonal expansion of exuberant T cells (or B cells in case of lymphomatoid papulosis) or by lineage infidelity. Three patients with unclassifiable disease had several clinical and histopathologic features in common. They were elderly, presented with solitary lesions, were in good general health and histopathologically demonstrated a dense multinodular infiltrate containing approximately an equal number of T and B cells and a high number of histiocytes forming granulomas, with prominent granulomatous features in 2 cases. B cells were either scattered with the infiltrate or formed collections vaguely resembling follicles; Reed-Sternberg-like cells were seen in 2 cases. B cells showed expression neither of immunoglobulin light chain. The T-cell component was represented mainly by small, well-differentiated lymphocytes or slightly pleomorphic cells, with some medium-sized convoluted cells. Epstein-Barr virus was not detected by polymerase chain reaction. The exact classification of these cases is unknown; they differ histopathologically from previously published cases of bigenotypic cutaneous lymphomas. They may merely represent a growth or reactive pattern, but, on the other hand, may be low-grade lymphomas. If so, they may be histopathologically related to cutaneous Hodgkin disease, T-cell/histiocyte-rich large B-cell lymphoma, or composite lymphomas. Further reports are needed to identify these lesions to clarify their nature and biologic potential.

Anogenital mammary-like glands, although known to exist (as ectopic breast tissue) as early as 1872, have only recently been thoroughly studied and suggested to be the possible origin for various neoplastic (benign and malignant) and reactive conditions that show a striking homology with lesions in the breast. Reported herein is an unusual benign lesion involving anogenital mammary-like glands in the perineal area of a 41-year-old woman. The lesion is unique in that it does not fully fit into any of the previously recognized conditions affecting anogenital mammary-like glands nor has it an apparent well-defined mammary counterpart. Microscopically, at first glance the lesion appeared as a cluster of extended anogenital mammary-like glands of variable complexity and a lobular architecture, which probably resulted from a compact proliferation of closely situated ducts with small, round lumens (when cut transversally). When cut longitudinally, some of these tiny ducts appeared to bud from larger ductal structures, resembling so-called satellitosis in the breast and this gave a fibroadenomatous appearance to the areas. In addition, there were adenosis-like areas. This lesion extends the spectrum of changes seen in anogenital mammary-like glands.

This study characterizes the clinicopathological spectrum of lymphoproliferations involving the breast nipple and/or areola. Morphologic, immunohistochemical, molecular-genetic, and clinical features of 58 specimens from 56 patients were analyzed. They were re-diagnosed as cutaneous lymphoid hyperplasia (CLH, n = 44); other benign lymphoid infiltrates (OBLI, n = 8); peripheral T-cell lymphoma, not otherwise specified (n = 1); cases with overlapping features of CLH and B-cell lymphoma (n = 3), one of them composed of spindle cells. Cutaneous lymphoid hyperplasia infiltrates were dense, composed mainly of B cells forming follicles with germinal centers (GC). Cutaneous lymphoid hyperplasia frequently showed features suggesting a malignancy as coalescing follicles with non-polarized germinal centers lacking mantle zones, and smudged infiltrates of lymphoid cells spreading into collagen (often as "Indian files"), smooth muscle, vessel walls, and nerve sheaths. Only two cutaneous lymphoid hyperplasias recurred; otherwise all patients are without disease (mean follow-up 62 months). Monoclonal rearrangement of immunoglobulin heavy chain gene was detected in five, and of T-cell receptor gamma gene in two cutaneous lymphoid hyperplasias using polymerase chain reaction (PCR), but the patients fared well too. In 47% of cases Borrelia burgdorferi was detected by polymerase chain reaction and/or serology, of which one was monoclonal. We conclude that cutaneous lymphoid hyperplasia is the most common lymphoproliferation of the breast nipple, rarely recognized clinically, and often overdiagnosed histologically as lymphoma.

Dendritic cell neurofibroma with pseudorosettes (DCNWPR) is a recently proposed variant of neurofibroma with a distinctive microscopic appearance that is produced by a pseudorosette pattern formed by small, dark, lymphocyte-like cells (Type I cells) arranged concentrically around larger cells, with pale-staining vesicular nuclei and copious faintly eosinophilic cytoplasm (Type II cells). Although DCNWPR appears not to be associated with neurofibromatosis (NF), 1 patient with DCNWPR has been described and suggested to have a form of NF because of multiple skin lesions, with 2 of them being DCNWPR as confirmed histologically. The aim of this study was to find out whether the neurofibromatosis type 2 (NF2) gene is mutated in DCNWPR. Seven histologically proven cases of DCNWPR, from which a substantial amount of archival paraffin-embedded material was available, were selected for this study. Three cases have been previously reported, including the intraneural lesion, and 4 cases were newly identified. There were 3 female and 4 male patients, ranging in age from 30 to 61 years (median, 48 yrs). All patients clinically presented with a small solitary lesion that was clinically diagnosed as fibroma or neurofibroma, and none of the patients had signs of NF. Follow-up was known for 6 patients (range, 1-5 yrs; median, 2.5 yrs) and was uneventful in each case. Microscopically, all lesions fulfilled the criteria for DCNWPR. Exons 1 to 15 of the NF2 gene were amplified by PCR using primers previously published. The amplified fragments were purified and sequenced. The obtained sequences were computer analyzed and compared with the data of the GenBank database. No mutation was identified in 5 analyzed samples from which suitable DNA had been extracted. DCNWPR appears to have no mutation in exons 1-15 of the NF2 gene. Given the relatively small number of cases studied, it seems premature to declare that a mutation of the NF2 gene is not involved in DCNWPR, as the possibility cannot be excluded that mutations were present but remained undetected because they occurred in exons that were not examined.