Morphologic diversity of malignant neoplasms arising in preexisting spiradenoma, cylindroma, and spiradenocylindroma based on the study of 24 cases, sporadic or occurring in the setting of Brooke-Spiegler syndrome. Am J Surg Pathol. 2009;33:705-719. [PMID: 19194280 DOI: 10.1097/PAS.0b013e3181966762]

A rare sweat gland tumor in an ovarian teratoma: Spiradenocylindroma case report

Background

Spiradenocylindroma is a benign tumor of skin adnexal origin with overlapping features of two distinct neoplasms: spiradenoma and cylindroma. This cutaneous tumor typically presents on the head and neck and extracutaneous presentations are uncommon. The presentation described below involves a spiradenocylindroma within a mature ovarian teratoma is very rare.

Aim

The aim of this article is to portray the diagnostic process of this unusual spiradenocylindroma presentation.

Case presentation

A 65 year-old female with a left adnexal mass underwent ultrasonography and magnetic resonance imaging (MRI) which showed a left ovarian multiseptated lesion, with mural calcifications and projections into the mass. Excisional surgery was performed and histopathological examination revealed a spiradenocylindroma.

Conclusion

Spiradenocylindroma is rare, hard to identify, and often misdiagnosed. Our study described the process of diagnosis and depicts the rare presentation of this lesion arising within a mature teratoma.

Spiradenoma With Adenoid Cystic Carcinoma-like Changes: A Case Series of This Rare Variant With a Potential Diagnostic Pitfall

Spiradenomas are benign cutaneous adnexal neoplasms with sweat gland differentiation that can manifest a broad spectrum of histomorphologic appearances. While they show a characteristic histopathologic phenotype and clinical management involves surgical excision with a low risk of recurrence, there have been unusual histopathologic variants of spiradenoma reported, including cases with adenoid cystic carcinoma (ACC)-like changes. Primary cutaneous ACC is a low-grade malignancy presenting as a subcutaneous mass with the potential for local invasion, perineural invasion, and high rates of local recurrence after excision. The diagnosis of spiradenomas with ACC-like features can be challenging, especially when only the ACC-like component is present for evaluation. A retrospective analysis of 21 cases of spiradenoma with ACC-like changes were obtained from large academic institutions, was performed, and summarized below. All cases showed background of conventional spiradenoma, and the ACC-like areas represented a component in all lesions. The percentage of ACC-like component ranged from 5% to 40% in all cases. The ACC-like component was multifocal and without pleomorphism, perineural and/or vascular invasion, necrosis, or increased mitotic activity. MYB translocation and protein expression was studied in 16 cases by fluorescence in situ hybridization, polymerase chain reaction, and immunohistochemistry. All studied cases were negative for MYB / NFIB , MYB L1, and MYB F by fluorescence in situ hybridization and polymerase chain reaction and 3 cases were positive for MYB expression by immunohistochemistry. Our study expands on spiradenomas with ACC-like features that ought to be considered in the differential diagnosis of cutaneous neoplasms such as primary cutaneous ACC. Our results indicate that a thorough histopathologic inspection and strict application of well-defined histologic criteria are necessary to support the diagnosis of this unusual histopathologic variant. These tumors can be difficult to diagnose, and awareness of their histomorphologic spectrum will facilitate definitive diagnosis and avoid misdiagnosis with other conditions.

Challenges in the diagnosis and treatment of the malignant adnexal neoplasms of the head and neck

PURPOSE OF REVIEW

The current review is to present the current knowledge regarding epidemiology, diagnostics, and management of malignant adnexal neoplasms (MANs).

RECENT FINDINGS

Immunotherapy and gene-related therapies are still being developed as the methods of salvage treatment in advanced and disseminated cases: CACNA1S, ATP2A1, RYR1, and MYLK3, as well as p53 or the JAK/STAT pathways, may be therapeutic targets; the efficiency of talimogene laherparepvec and nivolumab is assessed.

SUMMARY

MANs are rare tumors, but due to the aging of population their incidence is increasing. Their clinical presentation is unspecific, which makes the diagnosis challenging. Histopathological assessment is difficult even for experienced pathologists. Mohs micrographic surgery or wide local excision are recommended to treat primary lesions. Adjuvant radiotherapy may be beneficial in case of insufficient or positive surgical margins, in nodal metastases, in selected types of MANs like sebaceous, trichilemmal, and pilomatrix carcinomas, and as the induction treatment in large tumors located in medically fragile or cosmetically important regions. The role of chemotherapy is not well defined; however, it is recommended in distant metastases. Immunotherapy can improve the prognosis in advanced stage of the disease.

Distant metastasis from morphologically low-grade spiradenocarcinoma: A report of two cases

Malignant tumors arising from benign eccrine spiradenomas are rare. They are divided by morphology into low-grade and high-grade spiradenocarcinomas, with prognosis and metastatic potential closely linked to their histopathologic features. Tumors with low-grade morphology are known for their indolent behavior, with only two reported instances of metastatic spread. We report herein two further low-grade metastatic spiradenocarcinomas resulting in distant metastasis. Both tumors showed a background of a benign spiradenoma and subtle histopathologic signs of malignant transformation, characterized by loss of the dual-cell population, up to moderate cytological atypia and increased mitotic activity. Both patients developed metastases to the lungs years after the initial presentation, and one showed additional lymph nodal disease. We show that even the morphologically low-grade tumors may rarely show more aggressive behavior. Although often challenging, recognition of the morphologically low-grade malignant spiradenocarcinoma and long-term follow-up of the patients are important to detect metastatic disease.

Mass Forming Basement Membrane Material Secondary to Adnexal Adenocarcinoma - a Case Report

We report a 77-year-old male with biopsy proven adnexal adenocarcinoma where there was only mass deposit of basement membrane material in the therapeutic excision. To our knowledge, this finding is extremely rare and has not been previously described in the literature and necessitates distinction from other conditions which cause eosinophilic hyaline deposits within the dermis.

Microsatellite Instability in Near East Sebaceous Neoplasms: Toward Improved Prediction

Sebaceous neoplasms (SN) comprise a heterogeneous spectrum of tumors with different biological behaviors. In the Near-East Region (NER), microsatellite instability (MSI) in SN's development, and its correlation with the clinicopathologic features of tumors is not well elucidated. A cohort of 225 SN patients (40 benign SNs and 185 sebaceous carcinomas) from the NER was retrospectively reviewed. Clinical variables and available follow-up information were recorded. MSI proteins (MLH1, MSH2, MSH6, and PMS2) as well as P53, P16, EMA, CD8, and PDL-1 expressions were examined by immunohistochemistry. Detection of human papilloma virus was determined by polymerase chain reaction. Microscopic features such as mitotic count and tumor-infiltrating lymphocytes were documented. A minority of SNs from benign (n=2) or malignant (n=3) tumors in the NER exhibit MSI (2.2%). MSI is exclusively found in patients with extraocular lesions (back, n=5) and presented a poor outcome. Among these, PMS2 protein was mostly lost (average=80%, n=4). SN with MSI exhibited a significant increase in p53 expression, (average=62.10%, P=0.002). There was no significant correlation between MSI status and any of the following: PD-L1, CD8, p16, and human papilloma virus infection. Microscopically, SN with MSI show significantly higher mitotic count, cystic changes and increased tumor-infiltrating lymphocytes. MSI is rarely found in NER's SN. When detected, it is exclusively in extraocular SNs with minimal predicative microscopic features and worse outcome.

Malignant eccrine spiradenocylindroma and parotid gland involvement in brooke spiegler syndrome

Brooke-Spiegler syndrome is a rare disorder, characterized by the development of skin adnexal tumors, including cylindromas, trichoepitheliomas, spiradenomas. Although these neoplasms are benign in most patients, a malignant transformation can rarely occur. Furthermore, an occasional association between cutaneous adnexal tumors and basal cell adenoma as well as adenocarcinoma of the parotid gland has been rarely described, with approximately 20 cases reported. We report a case of BSS presenting with a malignant eccrine spiradenocylindroma, in a patient with previous history of parotid basal cell tumor.

Genetic Testing in CYLD Cutaneous Syndrome: An Update

CYLD cutaneous syndrome (CCS) is an inclusive label for the inherited skin adnexal tumour syndromes Brooke–Spiegler Syndrome (BSS-OMIM 605041), familial cylindromatosis (FC – OMIM 132700) and multiple familial trichoepitheliomas (MFT-OMIM 601606). All three syndromes arise due to germline pathogenic variants in CYLD, a tumour suppressor gene (OMIM 605018). CCS is transmitted in an autosomal dominant pattern, and has variable expressivity, both of the three syndromic phenotypes, and of the severity of tumour burden. Age-related penetrance figures are not precisely reported. The first tumours typically appear during puberty and progressively accumulate through adulthood. Penetrance is typically high, with equal numbers of males and females affected. Genetic testing is important for confirmation of the clinical diagnosis, genetic counselling and family planning, including preimplantation diagnosis. Additionally, identified CCS patients may be eligible for future clinical trials of non-surgical pre-emptive interventions that aim to prevent tumour growth. In this update, we review the clinical presentations of germline and mosaic CCS. An overview of the germline pathogenic variant spectrum of patients with CCS reveals more than 100 single nucleotide variants and small insertions and deletions in coding exons, most frequently resulting in predicted truncation. In addition, a minority of patients have large deletions involving the CYLD gene, intronic pathogenic variants that affect splicing, or inversions. We discuss germline and somatic testing approaches. Somatic testing of tumour tissue, relevant in mosaic CCS, can reveal recurrently detected pathogenic variants when two or more tumours are tested. This can influence genetic testing of children, who may inherit this as a germline variant, and inform genetic counselling and prenatal diagnosis. Finally, we discuss testing technologies that are currently used, their benefits and limitations, and future directions for genetic testing in CCS.

TRAF3 and NBR1 both influence the effect of the disease-causing CYLD(Arg936X) mutation on NF-κB activity

Recently described Hungarian and Anglo-Saxon pedigrees that are affected by CYLD cutaneous syndrome (syn: Brooke-Spiegler syndrome (BSS)) carry the same disease-causing mutation (c.2806C>T, p.Arg936X) of the cylindromatosis (CYLD) gene but exhibit striking phenotypic differences. Using whole exome sequencing, missense genetic variants of the TRAF3 and NBR1 genes were identified in the affected family members of the Hungarian pedigree that are not present in the Anglo-Saxon pedigree. This suggested that the affected proteins (TRAF3 and NBR1) are putative phenotype-modifying factors. An in vitro experimental system was set up to clarify how wild type and mutant TRAF3 and NBR1 modify the effect of CYLD on the NF-κB signal transduction pathway. Our study revealed that the combined expression of mutant CYLD(Arg936X) with TRAF3 and NBR1 caused increased NF-κB activity, regardless of the presence or absence of mutations in TRAF3 and NBR1. We concluded that increased expression levels of these proteins further strengthen the effect of the CYLD(Arg936X) mutation on NF-κB activity in HEK293 cells and may explain the phenotype-modifying effect of these genes in CYLD cutaneous syndrome. These results raise the potential that detecting the levels of TRAF3 and NBR1 might help explaining phenotypic differences and prognosis of CCS.

Current Diagnosis and Treatment Options for Cutaneous Adnexal Neoplasms with Apocrine and Eccrine Differentiation

Adnexal tumors of the skin are a rare group of benign and malignant neoplasms that exhibit morphological differentiation toward one or more of the adnexal epithelium types present in normal skin. Tumors deriving from apocrine or eccrine glands are highly heterogeneous and represent various histological entities. Macroscopic and dermatoscopic features of these tumors are unspecific; therefore, a specialized pathological examination is required to correctly diagnose patients. Limited treatment guidelines of adnexal tumor cases are available; thus, therapy is still challenging. Patients should be referred to high-volume skin cancer centers to receive an appropriate multidisciplinary treatment, affecting their outcome. The purpose of this review is to summarize currently available data on pathogenesis, diagnosis, and treatment approach for apocrine and eccrine tumors.

Spiradenoma With Adenoid Cystic Carcinoma-Like Features

Spiradenoma is a benign cutaneous adnexal neoplasm that characteristically presents as a painful dermal nodule, often on the head or trunk. It has a distinct histologic phenotype and management involves surgical excision with low risk of recurrence. In comparison, adenoid cystic carcinoma (ACC) is a low-grade malignancy manifesting as an often painless subcutaneous mass with potential for local invasion, perineural extension, and high rates of recurrence after excision. We report the case of a 63-year-old male patient with a recurrent, painful hematoma-like cyst overlying the left lower extremity tibial tuberosity. A firm nodule was located at the base of the cyst, which was histologically consistent with spiradenoma. Interestingly, the lesion contained multifocal ACC-like components composed of epithelial basaloid cells surrounding pseudocystic structures filled with mucinous material. The ACC-like components did not demonstrate infiltration or perineural invasion. To the best of our knowledge, this is the second publication in the English literature regarding spiradenoma with an ACC-like pattern. Although a benign entity, knowledge of this morphological variant of spiradenoma is essential for diagnostic accuracy in these cases. If a limited biopsy captures only the ACC-like component of a spiradenoma, the lesion may be incorrectly diagnosed as ACC.

CYLD mutation characterizes a subset of HPV-positive head and neck squamous cell carcinomas with distinctive genomics and frequent cylindroma-like histologic features

Mutations in the tumor suppressor CYLD, known to be causative of cylindromas, were recently described in a subset of high-risk (hr) HPV-positive head and neck squamous cell carcinomas (HNSCC). Pathologic and genetic characterization of these CYLD-mutant carcinomas, however, remains limited. Here, we investigated whether CYLD mutations characterize a histopathologically and genomically distinct subset of hrHPV-positive HNSCC. Comprehensive genomic profiling via hybrid capture-based DNA sequencing was performed on 703 consecutive head and neck carcinomas with hrHPV sequences, identifying 148 unique cases (21%) harboring CYLD mutations. Clinical data, pathology reports, and histopathology were reviewed. CYLD mutations included homozygous deletions (n = 61/148; 41%), truncations (n = 52; 35%), missense (n = 26; 18%) and splice-site (n = 9; 6%) mutations, and in-frame deletion (n = 1; 1%). Among hrHPV-positive HNSCC, the CYLD-mutant cohort showed substantially lower tumor mutational burden than CYLD-wildtype cases (n = 555) (median 2.6 vs. 4.4 mut/Mb, p < 0.00001) and less frequent alterations in PIK3CA (11% vs. 34%, p < 0.0001), KMT2D (1% vs. 16%, p < 0.0001), and FBXW7 (3% vs. 11%, p = 0.0018). Male predominance (94% vs. 87%), median age (58 vs. 60 years), and detection of HPV16 (95% vs. 89%) were similar. On available histopathology, 70% of CYLD-mutant HNSCC (98/141 cases) contained hyalinized material, consistent with basement membrane inclusions, within crowded aggregates of tumor cells. Only 7% of CYLD-wildtype cases demonstrated this distinctive pattern (p < 0.0001). Histopathologic patterns of CYLD-mutant HNSCC lacking basement membrane inclusions included nonkeratinizing (n = 22, 16%), predominantly nonkeratinizing (nonkeratinizing SCC with focal maturation; n = 10, 7%), and keratinizing (n = 11, 8%) patterns. The latter two groups showed significantly higher frequency of PTEN alterations compared with other CYLD-mutant cases (38% [8/21] vs. 7% [8/120], p = 0.0004). Within our cohort of hrHPV-positive HNSCCs, CYLD mutations were frequent (21%) and demonstrated distinctive clinical, histopathologic, and genomic features that may inform future study of prognosis and treatment.

Malignant Eccrine Adenoma With Sarcomatous (Heterologous) Components: Report of a Rare Skin Adnexal Neoplasm With Literature Review

Malignant eccrine spiradenoma (MES) is an exceedingly rare skin adnexal tumor that arises from pre-existing benign eccrine spiradenoma (BES). MES tumors show a wide spectrum of morphological features, posing a diagnostic challenge to the pathologist. Sarcomatous (heterologous) elements are seen in a few of these tumors, further complicating the morphological picture.

We herein describe a case of a 66-year-old male who presented with a recently enlarging, ulcerated, nodular skin lesion over the right leg that had been present for the last 25 years. The patient underwent wide local excision of the tumor.

Microscopic examination revealed a neoplastic lesion comprising benign and malignant components. The carcinomatous component showed features of infiltrating adenocarcinoma, not otherwise specified, whereas the sarcomatous component showed predominant osteosarcomatous and focal chondrosarcomatous differentiation. The benign component showed morphological and immunohistochemical features of BES. No adjuvant treatment was administered. The patient was alive and disease-free for 14 months, after which he was lost to follow-up.

Careful identification and knowledge related to histological diversity are keys to the correct diagnosis of this rare tumor. MESs are potentially aggressive tumors, and therefore, close long-term follow-up should be maintained.

CYLD-mutant cylindroma-like basaloid carcinoma of the anus: a genetically and morphologically distinct class of HPV-related anal carcinoma

Rare reports of anal carcinoma (AC) describe histologic resemblance to cutaneous cylindroma, but mutations in the tumor suppressor CYLD, the gene responsible for familial and sporadic cylindromas, have not been systematically investigated in AC. Here, we investigate CYLD-mutant AC, focusing on molecular correlates of distinct histopathology. Comprehensive genomic profiling (hybrid-capture-based DNA sequencing) was performed on 574 ACs, of which 75 unique cases (13%) harbored a CYLD mutation. Clinical data, pathology reports, and histopathology were reviewed for each CYLD-mutant case. The spectrum of CYLD mutations included truncating (n = 50; 67%), homozygous deletion (n = 10; 13%), missense (n = 16; 21%), and splice-site (n = 3; 4%) events. Compared with CYLD-wildtype AC (n = 499), CYLD-mutant ACs were significantly enriched for females (88% vs. 67%, p = 0.0001), slightly younger (median age 59 vs. 61 years, p = 0.047), and included near-universal detection of high-risk HPV sequences (97% vs. 88%, p = 0.014), predominantly HPV16 (96%). The CYLD-mutant cohort also showed significantly lower tumor mutational burden (TMB; median 2.6 vs. 5.2 mut/Mb, p < 0.00001) and less frequent alterations in PIK3CA (13% vs. 31%, p = 0.0015). On histopathologic examination, 73% of CYLD-mutant AC (55/75 cases) showed a striking cylindroma-like histomorphology, composed of aggregates of basaloid cells surrounded by thickened basement membranes and containing characteristic hyaline globules, while only 8% of CYLD-wildtype tumors (n = 34/409) contained cylindroma-like hyaline globules (p < 0.0001). CYLD-mutant carcinomas with cylindroma-like histomorphology (n = 55) showed significantly lower TMB compared with CYLD-mutant cases showing basaloid histology without the distinctive hyaline globules (n = 14) (median 1.7 vs. 4.4 mut/Mb, p = 0.0058). Only five CYLD-mutant cases (7%) showed nonbasaloid conventional squamous cell carcinoma histology (median TMB = 5.2 mut/Mb), and a single CYLD-mutant case showed transitional cell carcinoma-like histology. Within our cohort of ACs, CYLD mutations characterize a surprisingly large subset (13%), with distinct clinical and genomic features and, predominantly, a striking cylindroma-like histopathology, representing a genotype-phenotype correlation which may assist in classification of AC.

Metaplastic spiradenocarcinoma: Report of two cases with sarcomatous differentiation

Spiradenocarcinoma (SC) is a very rare malignant skin adnexal tumor with sweat gland differentiation that develops from a pre-existing spiradenoma, cylindroma, or hybrid tumor called spiradenocylindroma, or arises de novo. We present two exceptionally rare SC cases showing sarcomatous differentiation; we also discuss the clinicopathologic features of SC, as well as its differential diagnoses and available therapeutic modalities. Given the aggressive behavior of SC, rapid diagnosis and complete removal of the tumor with tumor-free margins is mandatory. Owing to the marked morphological heterogeneity of individual SC cases, dermatopathologists must be familiar with the different possible histopathologic manifestations of this neoplasm.

Brooke-Spiegler Syndrome With Cervical Spine Lesion

Brooke-Spiegler syndrome (BSS) is a rare hereditary autosomal dominant disorder with variable phenotypic expressivity that results in a variety of benign cutaneous face, scalp, and neck tumors with a histology profile of cylindroma, spiradenoma and trichoepithelioma. Reports of lymph node and distant metastasis are scarce. We present the first case of Brooke-Spiegler syndrome with metastasis to the cervical spine. An 86-year-old female with Brooke-Spiegler syndrome presented to the clinic with a finding of cervical spine lesion involving vertebral body, prevertebral, paraspinal, foraminal, and epidural spaces. The histopathology of the lesion showed benign cylindroma. Considering the location of the lesion and local invasion of neural structures, the malignant transformation of existing tumors could not be excluded. Brooke-Spiegler syndrome rarely presents with malignant transformation and distant metastatic spread. It is important to be aware of these rare cases while monitoring the disease and addressing clinical symptoms. This is to our knowledge the first case of metastatic spread of the cylindroma to the cervical spine resulting in local bone destruction and neural elements compromise. Physicians should be aware of this rare possibility.

Observations on Four Cases of Brooke–Spiegler Syndrome

Background: Brooke–Spiegler Syndrome is a rare genetic autosomal dominant disorder with variable penetrance. Its main feature consists of the development of multiple adnexal tumors that originate from the follicular-sebaceous-apocrine unit, most commonly: cylindromas, trichoepitheliomas and spiradenomas. Case presentation: We present four cases of Brooke–Spiegler Syndrome found in our clinic, as well as their clinicopathological traits and the surgical techniques used in their management. The familial history of three of the presented cases supports the genetic component of the disease. Cylindromas, spiradenomas and trichoepitheliomas coexisted in one of the cases presented. The therapeutic options used were electrocautery, CO2 laser, as well as tumor debulking followed by closure with metal staples. Discussion: The treatment remains a challenge and must be individualized based on the type, location and number of the lesions. Conservative methods such as CO2 laser and tumor debulking accompanied by closure with metal staples remain a viable option taking into account the large number of lesions. As patients usually develop multiple neoplasms throughout their lifetime, repeated procedures may be needed. Conclusion: Considering the few numbers of Brooke–Spiegler syndrome cases in the current literature, the authors report these patients in order to increase awareness and to help establish the most appropriate approach in managing the disease.

CYLD Alterations in the Tumorigenesis and Progression of Human Papillomavirus-Associated Head and Neck Cancers

Genetic alterations of CYLD lysine 63 deubiquitinase (CYLD), a tumor-suppressor gene encoding a deubiquitinase (DUB) enzyme, are associated with the formation of tumors in CYLD cutaneous syndrome. Genome sequencing efforts have revealed somatic CYLD alterations in multiple human cancers. Moreover, in cancers commonly associated with human papillomavirus (HPV) infection (e.g., head and neck squamous cell carcinoma), CYLD alterations are preferentially observed in the HPV-positive versus HPV-negative form of the disease. The CYLD enzyme cleaves K63-linked polyubiquitin from substrate proteins, resulting in the disassembly of key protein complexes and the inactivation of growth-promoting signaling pathways, including pathways mediated by NF-κB, Wnt/β-catenin, and c-Jun N-terminal kinases. Loss-of-function CYLD alterations lead to aberrant activation of these signaling pathways, promoting tumorigenesis and malignant transformation. This review summarizes the association and potential role of CYLD somatic mutations in HPV-positive cancers, with particular emphasis on the role of these alterations in tumorigenesis, invasion, and metastasis. Potential therapeutic strategies for patients whose tumors harbor CYLD alterations are also discussed. IMPLICATIONS: Alterations in CYLD gene are associated with HPV-associated cancers, contribute to NF-κB activation, and are implicated in invasion and metastasis.

Do not break a sweat: avoiding pitfalls in the diagnosis of sweat gland tumors

The group of malignant sweat gland neoplasms is characterized by a wide biologic spectrum, including tumors with indolent behavior, low-grade malignant potential with locally destructive tumor growth and high local recurrence rates and high-grade malignant potential characterized by risk for disseminated disease and disease-related mortality. Reliable diagnosis to predict behavior may be challenging for a number of reasons. The clinical presentation is often nonspecific. Many of the tumors are rare, and they are only infrequently encountered in routine diagnostic practice. A significant subset of tumors shows bland and innocuous histologic features. They are easily mistaken for benign tumors despite their potential for destructive growth and aggressive disease course. At the other end of the spectrum the tumors may resemble poorly differentiated carcinoma or adenocarcinoma and recognition relies entirely on sampling and carful histological examination. The tumors may be inseparable from cutaneous metastases from visceral primaries by morphology and immunohistochemistry, requiring careful clinical correlation and work-up. Conversely, cutaneous metastases are readily mistaken for cutaneous primary tumors. While the presence of a myoepithelial layer is a helpful feature in excluding metastatic deposits, it does not imply benign behavior of sweat gland tumors in general. The above issues and challenges are exemplified in the discussion of selected sweat gland carcinoma in this manuscript, with a focus on recently described entities and those with novel findings.

Primary Cutaneous Adenomyoepithelioma Ex Spiradenoma With Malignant Histologic Features, Epithelial-Myoepithelial Carcinoma Type: A First Case Report With Molecular Studies

Adenomyoepithelioma is an extremely rare primary cutaneous neoplasm. Although there is ample evidence on the existence of malignant adenomyoepithelioma in the breast, a malignant counterpart in the skin has not been documented. We report a primary cutaneous adenomyoepithelioma (pcAME) with malignant features arising from a spiradenoma in a 39-year-old female patient. The tumor was solid-cystic in appearance and entirely located in the subcutaneous tissue. Histologically, the tumor displayed foci of adenomatous changes and adenomyoepitheliomatous hyperplasia adjacent to a minute spiradenoma. Gradual increase of architectural complexity, cytologic atypia, mitotic activity, and infiltrative growth were observed in a significant portion of the neoplasm, indicative of transformation to adenomyoepithelioma and subsequently low- to high-grade salivary-type epithelial-myoepithelial carcinoma (EMCA). The intimate dual populations of ductal and myoepithelial cells were highlighted by a panel of immunohistochemical stains in all different components of the tumor. Molecular studies revealed a PIKCA3 mutation, a genetic aberration that has been documented in EMCA, particularly of breast origin. The current case documents for the first time a pcAME with malignant features arising from a spiradenoma and suggests adenomyoepithelioma ex spiradenoma as a possible tumorigenesis pathway of this rare cutaneous tumor.

Epigenetic modifiers DNMT3A and BCOR are recurrently mutated in CYLD cutaneous syndrome

Patients with CYLD cutaneous syndrome (CCS; syn. Brooke-Spiegler syndrome) carry germline mutations in the tumor suppressor CYLD and develop multiple skin tumors with diverse histophenotypes. Here, we comprehensively profile the genomic landscape of 42 benign and malignant tumors across 13 individuals from four multigenerational families and discover recurrent mutations in epigenetic modifiers DNMT3A and BCOR in 29% of benign tumors. Multi-level and microdissected sampling strikingly reveal that many clones with different DNMT3A mutations exist in these benign tumors, suggesting that intra-tumor heterogeneity is common. Integrated genomic, methylation and transcriptomic profiling in selected tumors suggest that isoform-specific DNMT3A2 mutations are associated with dysregulated methylation. Phylogenetic and mutational signature analyses confirm cylindroma pulmonary metastases from primary skin tumors. These findings contribute to existing paradigms of cutaneous tumorigenesis and metastasis.

An Overview of Uncommon Cutaneous Malignancies, Including Skin Appendageal (Adnexal) Tumours and Sarcomas

A standardised classification of malignant skin appendageal (adnexal) tumours and sarcomas is required for improved patient management and prognosis. This has been hindered by considerable morphological variation both within and between tumour types, the use of many synonyms for the same tumour types and variation in classification between pathologists. This update uses the improved classification in the 2018 WHO classification of skin tumours as the basis to discuss malignant skin appendageal tumours, sarcomas and cutaneous metastases that regularly present to skin cancer clinicians, multidisciplinary skin cancer teams and tumour boards, with current evidence for management, where appropriate.

The E3 ubiquitin ligase MIB2 enhances inflammation by degrading the deubiquitinating enzyme CYLD

The tumor suppressor CYLD is a deubiquitinating enzyme that suppresses polyubiquitin-dependent signaling pathways, including the proinflammatory and cell growth-promoting NF-κB pathway. Missense mutations in the CYLD gene are present in individuals with syndromes such as multiple familial trichoepithelioma (MFT), but the pathogenic roles of these mutations remain unclear. Recent studies have shown that CYLD interacts with a RING finger domain protein, mind bomb homologue 2 (MIB2), in the regulation of NOTCH signaling. However, whether MIB2 is an E3 ubiquitin ligase that acts on CYLD is unknown. Here, using the cell-free-based AlphaScreen and pulldown assays to detect protein-protein interactions, along with immunofluorescence assays and murine Mib2 knockout cells and animals, we demonstrate that MIB2 promotes proteasomal degradation of CYLD and enhances NF-κB signaling. Of note, arthritic inflammation was suppressed in Mib2-deficient mice. We further observed that the ankyrin repeat in MIB2 interacts with the third CAP domain in CYLD and that MIB2 catalyzes Lys-48-linked polyubiquitination of CYLD at Lys-338 and Lys-530. MIB2-dependent CYLD degradation activated NF-κB signaling via tumor necrosis factor alpha (TNFα) stimulation and the linear ubiquitination assembly complex (LUBAC). Mib2-knockout mice had reduced serum interleukin-6 (IL-6) and exhibited suppressed inflammatory responses in the K/BxN serum-transfer arthritis model. Interestingly, MIB2 significantly enhanced the degradation of a CYLD^P904L variant identified in an individual with MFT, although the molecular pathogenesis of the disease was not clarified here. Together, these results suggest that MIB2 enhances NF-κB signaling in inflammation by promoting the ubiquitin-dependent degradation of CYLD.

Magnifying glass on spiradenoma and cylindroma histogenesis and tumorigenesis using systematic transcriptome analysis

Spiradenoma and cylindroma are related sweat gland tumors. To delineate their histogenesis, gene profiles, and their potential drivers, we performed a whole-transcriptome sequencing analysis of fourteen samples of spiradenoma/cylindroma in comparison to normal samples. A total of 12 spiradenomas, 5 cylindromas, 3 hybrid spiradenomas/cylindromas and 2 adnexal carcinomas were included in this study. 1335 characteristic genes and transcripts expressed over all 14 spiradenoma/cylindroma tumors were identified, and two groups of expression profiles were observed. Highest upregulated top 7 gene signatures characterized benign tumors with developmental and differentiation related genes, and carcinomas with top 7 genes mainly related to signaling, reorganization and metabolism of membranes. Immunohistochemistry of protein expressions validated 4 upregulated genes (ODAM, HOXB13, MYB and SOX10) considered important and as potential biomarkers for spiradenomas and cylindromas. We further compared the transcriptome of eccrine adnexal tumors with the transcriptome of adenoid cystic carcinoma (ACC) to identify the overlapping genes that may indicate histogenesis. There were 36 specific genes overlapping between adnexal carcinomas and the epithelial-dominant subtype of ACC, and 27 specific genes overlapping benign adnexal tumors with the myoepithelial-dominant subtype of ACC, At this point there is no known specific biomarker to aid in the diagnosis of eccrine spiradenoma and cylindroma in small samples or biopsies within the context of morphological overlap with ACC. In conclusion, spiradenomas and cylindromas are characterized by overexpressed developmental genes, where LHX2 and activated WNT signaling possibly drive associated carcinomas.

ALPK1 hotspot mutation as a driver of human spiradenoma and spiradenocarcinoma

Spiradenoma and cylindroma are distinctive skin adnexal tumors with sweat gland differentiation and potential for malignant transformation and aggressive behaviour. We present the genomic analysis of 75 samples from 57 representative patients including 15 cylindromas, 17 spiradenomas, 2 cylindroma-spiradenoma hybrid tumors, and 24 low- and high-grade spiradenocarcinoma cases, together with morphologically benign precursor regions of these cancers. We reveal somatic or germline alterations of the CYLD gene in 15/15 cylindromas and 5/17 spiradenomas, yet only 2/24 spiradenocarcinomas. Notably, we find a recurrent missense mutation in the kinase domain of the ALPK1 gene in spiradenomas and spiradenocarcinomas, which is mutually exclusive from mutation of CYLD and can activate the NF-κB pathway in reporter assays. In addition, we show that high-grade spiradenocarcinomas carry loss-of-function TP53 mutations, while cylindromas may have disruptive mutations in DNMT3A. Thus, we reveal the genomic landscape of adnexal tumors and therapeutic targets.

p63 and smooth muscle actin expression in low-grade spiradenocarcinomas in a case of CYLD cutaneous syndrome

Low-grade spiradenocarcinoma is a rare skin tumor, with fewer than six reported cases, arising in the context of CYLD cutaneous syndrome (CCS; syn: Brooke-Spiegler syndrome [BSS]). We report two independent cases of spiradenocarcinoma arising in a 50-year-old man with CCS. The tumors grew rapidly, prompting clinical excision. The histologic features in our cases corresponded to the salivary gland type basal cell adenocarcinoma-like pattern, low grade (BCAC-LG), that has been previously recognized as a recurrent finding in CCS. We performed genetic testing of the patient and found a novel mutation in CYLD. Recognition of low-grade spiradenocarcinoma can be difficult for the pathologist as the features can be subtle, especially in those cases where the transition from benign to malignant tumor is gradual. We examined p63 and smooth muscle actin (SMA) expression patterns in BCAC-LG and compared it with the expression pattern in the precursor spiradenoma. Our report provides information on two rare tumors in the context of CCS and suggests that the pattern of p63 and SMA staining may aid pathological detection of the BCAC-LG subtype of spiradenocarcinoma.

Cancerous Protein Network That Inhibits the Tumor Suppressor Function of WW Domain-Containing Oxidoreductase (WWOX) by Aberrantly Expressed Molecules

Recent findings indicate that the WW domain-containing oxidoreductase (WWOX) is a tumor suppressor protein that contains two N-terminal WW domains and a central short-chain dehydrogenase/reductase domain. WWOX protein mediates multiple signaling networks that suppress carcinogenesis through binding of its first WW domain to various cancer-associated proteins, i.e., p73, AP-2γ, and others. Although the tumor suppressor property of WWOX is inarguable, WWOX is not inactivated in the manner characteristic of the canonical Knudson hypothesis. Impairment of both alleles of WWOX is thought to be a rare event, only occurring in a few cancer cell lines. How is the tumor suppressor function of WWOX impaired in cancer cells? Recent advances highlight that a small transmembrane protein possessing a PPxY motif, called TMEM207, and its relatives are aberrantly expressed in various cancer cells and hinder the tumor suppressor function of WWOX through inhibiting its WW domain. Here, we review the recent findings related to the pathobiological properties of TMEM207 and its relatives based on clinicopathological and experimental pathological studies.

Spiradenocarcinoma: A Comprehensive Data Review

INTRODUCTION

Spiradenocarcinomas (SCs) are rare and potentially aggressive skin adnexal tumors. Optimal treatment has not yet been established. Experiences with this carcinoma are mostly presented in case reports and few case series.

OBJECTIVE

To generate to a synopsis of published data on SC with regard to diagnostic procedures, treatment, and outcome.

RESULTS

Median patient age was 60 years and sex distribution was balanced. Tumor manifestations were evenly distributed within the sweat gland carrying skin. The most commonly reported symptom was accelerated growth of a longstanding indolent lesion, typically present for more than 2 years. Metastatic spread to the lung, bone, lymph nodes, liver, kidney, and breast has been documented. For staging computed tomography (CT) and positron emission tomography-CT are recommended, especially for detection of hematogenic metastases and lymph node involvement. Clear resection margins and tumor free regional lymph nodes reduce recurrence and carcinoma related death. Although low-grade SCs were reported over 3 times more often, high-grade carcinomas show a greater likelihood for recurrence and lethal outcome.

CONCLUSION

Suspicion of an SC should lead to performance of a magnetic resonance imaging for defining tumor extent, and a fludeoxyglucose positron emission tomography-CT for detection of metastases. Radical tumor excision and resection of tumor involved regional lymph nodes are essential for a curative approach. Histopathological evaluation should involve determination of tumor differentiation grade, because high-grade carcinomas seem to have a much more aggressive behavior. Excision of distant metastases has no therapeutic value. Follow-up needs to be carried out in short intervals with frequent imaging.

Update on Malignant Sweat Gland Tumors

Malignant sweat gland tumors are rare cutaneous neoplasms, traditionally separated according to their behavior into low- and high-grade malignant. There is significant morphologic overlap, and outright malignant tumors may show relatively bland histologic features. They may, therefore, be mistaken easily for benign neoplasms. Recognition of these tumors and accurate diagnosis is important for early treatment to prevent aggressive behavior and adverse outcome. This article provides an overview of 4 important entities with emphasis on diagnostic pitfalls, differential diagnosis and recent developments. Microcystic adnexal carcinoma, squamoid eccrine ductal carcinoma, aggressive digital papillary adenocarcinoma, and spiradenocarcinoma are discussed in detail.

[Malignant transformation of an eccrine spiradenoma]

INTRODUCTION

Malignant eccrine spiradenoma is a rare and aggressive tumor, developed on the epithelium of eccrine sweat glands. Typically, it occurs after malignant transformation of benign eccrine spiradenoma, but sometimes it happens de novo.

OBSERVATION

We report a case of malignant eccrine spiradenoma in a 62-year-old woman. The patient presented a rapid increase in size of a long-standing tumoral lesion of her forearm. There was no secondary lesion on the chest, abdomen or pelvis at the CT-scanner. Cutaneous biopsy of the lesion was performed and showed a carcinoma with no contact with epidermis. On this biopsy, we could not affirm if the tumor was a metastatic process or a primary tumor of the skin. Histologic examination of the surgical removal of the tumor showed an undifferentiated carcinoma with adjacent nodules of eccrine spiradenoma. Immunohistochemical assessment of Ki67 expression showed a weak expression (5%) in the benign spiradenoma nodules and a high rate expression (80%) in the malignant neoplasm. The final diagnosis was an undifferentiated carcinoma arising from preexisting benign spiradenoma.

DISCUSSION

Malignant eccrine spiradenoma is not frequent and is rarely described in the international literature that may lead to diagnostic difficulties.

A New Hitherto Unreported Histopathologic Manifestation of Mammary Analogue Secretory Carcinoma: "Masked MASC" Associated With Low-grade Mucinous Adenocarcinoma and Low-grade In Situ Carcinoma Components

We present a salivary gland tumor of the parotid gland in a 54-year-old woman, which contained a minor mammary analogue secretory carcinoma (MASC) component (20%) intermixed with a morphologically entirely different mucinous adenocarcinomatous component that comprised 80% of the tumor mass and a morphologically nondescript low-grade intraductal carcinoma (in situ) component. On fluorescence in situ hybridization, a break in the ETV6 gene was documented in the mucinous adenocarcinomatous, the conventional MASC, and the intraductal (in situ) components. RT-PCR failed to reveal an ETV6-NTRK3 fusion. The entire conventional MASC and only rare mucinous adenocarcinoma tumor cells were mammaglobin positive, whereas the low-grade intraductal carcinoma (in-situ) component was negative. S-100 protein stained only the MASC component.

The cylindromatosis (CYLD) gene and head and neck tumorigenesis

Germline CYLD mutation is associated with the development of a rare inheritable syndrome, called the CYLD cutaneous syndrome. Patients with this syndrome are distinctly presented with multiple tumors in the head and neck region, which can grow in size and number over time. Some of these benign head and neck tumors can turn into malignancies in some individuals. CYLD has been identified to be the only tumor suppressor gene reported to be associated with this syndrome thus far. Here, we summarize all reported CYLD germline mutations associated with this syndrome, as well as the reported paired somatic CYLD mutations of the developed tumors. Interestingly, whole-exome sequencing (WES) studies of multiple cancer types also revealed CYLD mutations in many human malignancies, including head and neck cancers and several epithelial cancers. Currently, the role of CYLD mutations in head and neck carcinogenesis and other cancers is poorly defined. We hope that this timely review of recent findings on CYLD genetics and animal models for oncogenesis can provide important insights into the mechanism of head and neck tumorigenesis.

Overexpression of MYB drives proliferation of CYLD-defective cylindroma cells

Cutaneous cylindroma is an adnexal tumour with apocrine differentiation. A predisposition to multiple cylindromas is seen in patients with Brooke-Spiegler syndrome, who carry germline mutations in the tumour suppressor gene CYLD. Previous studies of inherited cylindromas have highlighted the frequent presence of bi-allelic truncating CYLD mutations as a recurrent driver mutation. We have previously shown that sporadic cylindromas express either MYB-NFIB fusion transcripts or show evidence of MYB activation in the absence of such fusions. Here, we investigated inherited cylindromas from several families with germline CYLD mutations for the presence of MYB activation. Strikingly, none of the inherited CYLD-defective (n = 23) tumours expressed MYB-NFIB fusion transcripts. However, MYB expression was increased in the majority of tumours (69%) and global gene expression analysis revealed that well-established MYB target genes were up-regulated in CYLD-defective tumours. Moreover, knock-down of MYB expression caused a significant reduction in cylindroma cell proliferation, suggesting that MYB is also a key player and oncogenic driver in inherited cylindromas. Taken together, our findings suggest molecular heterogeneity in the pathogenesis of sporadic and inherited cutaneous cylindromas, with convergence on MYB activation. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Brooke-Spiegler Syndrome and Phenotypic Variants: An Update

Brooke-Spiegler syndrome (BSS) is an inherited autosomal dominant disease characterized by the development of multiple adnexal cutaneous neoplasms most commonly spiradenoma, cylindroma, spiradenocylindroma, and trichoepithelioma. Multiple familial trichoepithelioma (MFT) is a phenotypic variant of the disease characterized by the development of numerous trichoepitheliomas (cribriform trichoblastoma) only. Malignant tumors arise in association with preexisting benign cutaneous neoplasms in about 5-10% of the patients . Apart from the skin, major and minor salivary glands have been rarely involved in BSS patients. Extremely rare is the occurrence of breast tumors (cylindroma). The gene implicated in the pathogenesis of the disease is the CYLD gene, a tumor suppressor gene located on chromosome 16q12-q13. Germline CYLD mutations are detected in about 80-85% of patients with the classical BSS phenotype and in about 40-50% of the individuals with the MFT phenotype using a PCR based approach with analysis of exonic sequences and exon-intron junctions of the CYLD gene. There appears to be no genotype-phenotype correlations with respect to the severity of the disease, the possibility of malignant transformation, and development of extracutaneous lesions.

Syringometaplasia: variants and underlying mechanisms

Syringometaplasia is an adaptive, benign, metaplastic cellular process that affects the eccrine ducts and glands in response to a variety of physiological or pathological stimuli. Different subtypes of syringometaplasia have been described, including the squamous, mucinous, and adenomatous types. These metaplastic changes have been reported in association with chemotherapeutic agents, as well as with a variety of skin disorders including multiple infectious, neoplastic, and inflammatory skin diseases. In this review, we attempt to shed light on the different patterns of syringometaplasia, its pathogenesis, the plethora of skin conditions in which it may be observed, and the differential diagnoses that should be considered.

Breast Neoplasms with Dermal Analogue Differentiation (Mammary Cylindroma): Report of 3 Cases and a Proposal for a New Terminology

Salivary gland-like and dermal analogue tumours of the breast are rare lesions that can be diagnostically challenging for pathologists. Data on the clinical behaviour and molecular characterisation of these mammary tumours are limited and their designation is mainly based on similar salivary gland or skin lesions. In this study, we present three cylindromatous breast tumours. These lesions were located within the breast, had ill-defined margins and were composed of nests containing a dual population of cytologically bland cells, surrounded at least partially by basement membrane-like material. The lack of cytological atypia and absence of mitoses led to the diagnosis of benign mammary cylindroma in 1 case. The expression of oestrogen receptor, focal absence of basement membrane material and the focal infiltrative nature together with patchy absence of peripheral basement membrane supported the diagnosis of malignancy in the other 2 cases. We discuss the morphological criteria, immunohistochemical profile and diagnostic pitfalls of these tumours. We also review the literature including previously reported cases of mammary cylindroma and differential diagnoses to be considered before making a diagnosis. We propose the term 'mammary tumours with cylindromatous differentiation', implying their uncertain malignant nature, and propose management strategies.