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The American Journal of Dermatopathology Feb 2024The distinction between digital papillary adenocarcinoma (DPAC) and benign cutaneous adnexal tumors is clinically important and can be challenging. Poroid hidradenoma...
The distinction between digital papillary adenocarcinoma (DPAC) and benign cutaneous adnexal tumors is clinically important and can be challenging. Poroid hidradenoma frequently occurs at acral sites and can show a number of histological features, which overlap with digital papillary adenocarcinoma. Recent work has shown that YAP1-NUTM1 fusions are frequent in poroid hidradenoma and are associated with nuclear protein in testis (NUT) expression by immunohistochemistry. We evaluated the expression of NUT-1 by immunohistochemistry in 4 cases of DPAC and 4 cases of poroid hidradenoma. Three of 4 cases of poroid hidradenoma showed strong NUT-1 expression, with no staining in any of the cases of DPAC. These results suggest that NUT-1 immunohistochemistry may be a useful additional tool in evaluating this differential diagnosis.
Topics: Male; Humans; Carcinoma, Papillary; Acrospiroma; Sweat Gland Neoplasms; Adenocarcinoma, Papillary; Poroma
PubMed: 37982500
DOI: 10.1097/DAD.0000000000002596 -
Clinical, Cosmetic and Investigational... 2023Eccrine poroma (EP) is a benign skin appendicular tumor that differentiates into the terminal sweat duct and is often differentiated from basal cell carcinoma (BCC) and...
Eccrine poroma (EP) is a benign skin appendicular tumor that differentiates into the terminal sweat duct and is often differentiated from basal cell carcinoma (BCC) and seborrheic keratosis. This report describes a 58-year-old woman who presented with left occipital plaque. Histopathological analysis showed that the tumor cells were located in the lower part of the epidermis. The tumor cells were cuboidal or circular basal-like cells of the same size. The surrounding cells were not arranged in a palisade shape. Scattered tumor clusters composed of basal-like cells were also seen in the dermis, staining basophilic, and the surrounding cells were arranged in a palisade pattern. Immunohistochemistry showed that BerEP4, epithelial membrane antigen EMA, carcinoembryonic antigen CEA, Bcl-2, CD10, CK7 were positive, AR, PAS were negative. According to the pathological examination and immunohistochemical results, a case of eccrine poroma with concurrent basal cell carcinoma was diagnosed.
PubMed: 37881203
DOI: 10.2147/CCID.S428611 -
Histopathology Jan 2024Merkel cell carcinoma (MCC) is frequently caused by the Merkel cell polyomavirus (MCPyV). Characteristic for these virus-positive (VP) MCC is MCPyV integration into the...
AIMS
Merkel cell carcinoma (MCC) is frequently caused by the Merkel cell polyomavirus (MCPyV). Characteristic for these virus-positive (VP) MCC is MCPyV integration into the host genome and truncation of the viral oncogene Large T antigen (LT), with full-length LT expression considered as incompatible with MCC growth. Genetic analysis of a VP-MCC/trichoblastoma combined tumour demonstrated that virus-driven MCC can arise from an epithelial cell. Here we describe two further cases of VP-MCC combined with an adnexal tumour, i.e. one trichoblastoma and one poroma.
METHODS AND RESULTS
Whole-genome sequencing of MCC/trichoblastoma again provided evidence of a trichoblastoma-derived MCC. Although an MCC-typical LT-truncating mutation was detected, we could not determine an integration site and we additionally detected a wildtype sequence encoding full-length LT. Similarly, Sanger sequencing of the combined MCC/poroma revealed coding sequences for both truncated and full-length LT. Moreover, in situ RNA hybridization demonstrated expression of a late region mRNA encoding the viral capsid protein VP1 in both combined as well as in a few cases of pure MCC.
CONCLUSION
The data presented here suggest the presence of wildtype MCPyV genomes and VP1 transcription in a subset of MCC.
Topics: Humans; Carcinoma, Merkel Cell; Merkel cell polyomavirus; Polyomavirus Infections; Poroma; Skin Neoplasms; Sweat Gland Neoplasms; Genomics
PubMed: 37830288
DOI: 10.1111/his.15068 -
Clinical and Experimental Dermatology Jan 2024
Topics: Humans; Poroma; Dermoscopy; Carcinoma, Basal Cell; Skin Neoplasms; Sweat Gland Neoplasms
PubMed: 37811873
DOI: 10.1093/ced/llad349 -
Experimental Dermatology Nov 2023
Topics: Humans; Poroma; Imaging, Three-Dimensional; Diagnosis, Differential; Sweat Gland Neoplasms; Microscopy, Confocal
PubMed: 37750378
DOI: 10.1111/exd.14936 -
Journal of Cutaneous Pathology Nov 2023Transcriptional repressor GATA binding 1 (TRPS1) is a transcription factor recently shown to play a role in the development of breast and liver cancer. Here, we evaluate...
BACKGROUND
Transcriptional repressor GATA binding 1 (TRPS1) is a transcription factor recently shown to play a role in the development of breast and liver cancer. Here, we evaluate TRPS1 immunoexpression in normal skin tissues and various cutaneous tumors.
METHODS
TRPS1 immunohistochemistry was performed in 109 cases of primary cutaneous tumors and 19 cases of metastatic carcinomas. TRPS1 expression was also evaluated in the normal skin tissues.
RESULTS
The normal epidermis was TRPS1-. In contrast, the eccrine apparatus, epithelial compartment of the hair follicles, hair papilla, sebaceous glands, and anogenital mammary-like glands were TRPS1+. In primary cutaneous tumors, TRPS1 positivity varied in poroma (2/3), nodular hidradenoma (4/5), spiradenoma (4/4), cutaneous mixed tumor (5/5), trichilemmal cyst (7/8), proliferating trichilemmal tumor (1/3), pilomatricoma (9/9), sebaceoma (2/5), extramammary Paget disease (13/13), sebaceous carcinoma (2/2), actinic keratosis (3/10), Bowen disease (7/12), and squamous cell carcinoma (1/5) cases. All cases of seborrheic keratosis, basal cell carcinoma, Merkel cell carcinoma, and malignant melanoma were TRPS1-. All metastatic breast carcinoma cases (8/8) were highly positive for TRPS1, while all but one of the other metastatic tumor cases were TRPS1-.
CONCLUSIONS
TRPS1 immunoexpression was observed in several skin appendages and cutaneous tumors.
PubMed: 37649299
DOI: 10.1111/cup.14523 -
Diagnostics (Basel, Switzerland) Aug 2023Eccrine poroma (EP) is a relatively rare benign adnexal neoplasm that usually affects elderly patients. Its pathogenesis is still under investigation, but recent gene... (Review)
Review
Eccrine poroma (EP) is a relatively rare benign adnexal neoplasm that usually affects elderly patients. Its pathogenesis is still under investigation, but recent gene studies have revealed gene fusions as key incidences resulting in oncogenetic pathways. It often presents as a solitary, firm papule, mostly asymptomatic, located on the soles or palms. Due to its clinical and dermoscopic variability, it is characterized as the great imitator. We performed a literature review, aiming to summarize current data on the pathogenetic mechanisms, new dermoscopic features, and novel diagnostic tools that may aid in early diagnosis and proper management of this rare adnexal tumor. Furthermore, we reviewed the possible pathogenetic associations between EP and its malignant counterpart, namely eccrine porocarcinoma. This systematic approach may aid in understanding the pathogenetic mechanisms and how to use novel histopathologic markers and imaging methods to overcome the diagnostic dilemma of this rare tumor.
PubMed: 37627947
DOI: 10.3390/diagnostics13162689 -
Yonago Acta Medica Aug 2023Psoriasis is a common chronical inflammatory skin disease with a prevalence of 2%-4% worldwide. In contrast, porocarcinoma is a relatively rare cutaneous neoplasm and an...
Psoriasis is a common chronical inflammatory skin disease with a prevalence of 2%-4% worldwide. In contrast, porocarcinoma is a relatively rare cutaneous neoplasm and an associated localization of both lesions is rare. Here, we describe the first case of porocarcinoma in a patient with psoriasis. A 71-year-old Japanese man was referred to our clinic for evaluation of nodule within a keratotic plaque of 20-years history on his leg. Histopathological examination showed that the plaque revealed acanthosis with regular elongation of rete ridges, agranulosis and the presence of Munro microabscesses. In contrast, massive proliferation of atypical poroid cells and a few cuticular cells in the dermis were seen in the nodule. We speculated that it is likely the porocarcinoma was caused by the elevated risk of skin cancer due to chronic inflammatory process of psoriasis itself in our patient.
PubMed: 37621981
DOI: 10.33160/yam.2023.08.005 -
Histopathology Jan 2024Poroma is a benign sweat gland tumour showing morphological features recapitulating the superficial portion of the eccrine sweat coil. A subset of poromas may transform... (Review)
Review
Poroma is a benign sweat gland tumour showing morphological features recapitulating the superficial portion of the eccrine sweat coil. A subset of poromas may transform into porocarcinoma, its malignant counterpart. Poroma and porocarcinoma are characterised by recurrent gene fusions involving YAP1, a transcriptional co-activator, which is controlled by the Hippo signalling pathway. The fusion genes frequently involve MAML2 and NUTM1, which are also rearranged in other cutaneous and extracutaneous neoplasms. We aimed to review the clinical, morphological and molecular features of this category of adnexal neoplasms with a special focus upon emerging differential diagnoses, and discuss how their systematic molecular characterisation may contribute to a standardisation of diagnosis, more accurate classification and, ultimately, refinement of their prognosis and therapeutic modalities.
Topics: Humans; Poroma; Eccrine Porocarcinoma; Skin Neoplasms; Sweat Gland Neoplasms; Skin; Transcription Factors
PubMed: 37609771
DOI: 10.1111/his.15023 -
Histopathology Nov 2023Metaplastic thymoma is a rare thymic tumour characterized by Yes Associated Protein 1 (YAP1) and Mastermind Like Transcriptional Coactivator 2 (MAML2) gene fusions...
AIMS
Metaplastic thymoma is a rare thymic tumour characterized by Yes Associated Protein 1 (YAP1) and Mastermind Like Transcriptional Coactivator 2 (MAML2) gene fusions resulting from an intrachromosomal inversion of chromosome 11. Immunohistochemistry with an antibody directed against the C-terminus of YAP1 has shown loss of expression in YAP1-rearranged vascular neoplasms, poromas, and porocarcinomas. This study aimed to validate an anti-YAP1 C-terminal antibody as an ancillary immunohistochemical marker for the diagnosis of metaplastic thymoma.
MATERIALS AND METHODS
Ten metaplastic thymomas were selected for the current study. Fluorescence in situ hybridization (FISH), next-generation sequencing (NGS), and reverse transcription-polymerase chain reaction (RT-PCR) analyses were performed to detect YAP1::MAML2 fusions. We then performed immunohistochemistry to detect YAP1 C-terminus expression in 10 metaplastic thymomas, 50 conventional thymomas (10 each of type A thymoma, type AB thymoma, type B1 thymoma, type B2 thymoma, and type B3 thymoma) and seven thymic carcinomas.
RESULTS
All 10 cases showed narrow split signals with a distance of nearly two signal diameters and sometimes had false-negative results in YAP1 and MAML2 break-apart FISH (BA-FISH). Abnormal colocalized signals of the YAP1::MAML2 fusion were observed in all 10 cases using fusion FISH (F-FISH) assays. Eight of 10 cases with adequate nucleic acids were successfully sequenced and all showed YAP1::MAML2 fusions; in two cases the fusions were detected by both DNA and RNA sequencing and in six cases by RNA sequencing only. YAP1::MAML2 fusion transcripts were identified in four cases by RT-PCR. Metaplastic thymoma showed loss of YAP1 C-terminus expression in all 10 (100%) cases. All other thymic neoplasms showed retained YAP1 C-terminus expression.
CONCLUSION
YAP1 C-terminus immunohistochemistry is a highly sensitive and specific ancillary marker that distinguishes metaplastic thymoma from its mimics. BA-FISH assays could not effectively detect YAP1::MAML2 fusions due to the proximity of the two genes. Loss of YAP1 C-terminus expression is a reliable surrogate for the detection of YAP1::MAML2 fusions in metaplastic thymoma.
Topics: Humans; Thymoma; In Situ Hybridization, Fluorescence; Transcription Factors; Thymus Neoplasms; Adaptor Proteins, Signal Transducing; Gene Rearrangement; Trans-Activators
PubMed: 37565303
DOI: 10.1111/his.15024