Journal of Cutaneous Pathology

Lymphomatoid papulosis (LyP) with DUSP22-IRF4 rearrangement is a rare, recently described variant of LyP histopathologically characterized by a biphasic growth pattern, with epidermotropic small-to-medium-sized atypical T-cells and dermal large and transformed T-cells diffusely expressing CD30. LyP with DUSP22-IRF4 rearrangement can mimic other cutaneous lymphoproliferative disorders, particularly primary cutaneous anaplastic large cell lymphoma (PCALCL) or transformed mycosis fungoides (MF). Unlike PCALCL or transformed MF, LyP with DUSP22-IRF4 rearrangement shows an indolent clinical behavior, with frequent spontaneous regression of untreated lesions...

For a small yet significant proportion of melanocytic lesions, histopathologic analysis may be unable to definitively evaluate malignant potential. These cases may signify a specific need for newer ancillary diagnostic technologies, including in vivo reflectance confocal microscopy (RCM) and gene expression profiling (GEP), both of which are highly sensitive in the diagnosis of melanoma. We report four cases of clinically suspicious melanocytic lesions that lacked definitive malignant features on histopathology and that were aided by use of RCM and GEP...

No abstract text is available yet for this article.

No abstract text is available yet for this article.

Cutaneous VCL::ALK fusion spindle (ovoid) cell tumor is unique. Recently emerged RAS::MAP tyrosine kinase fusion sarcomas more commonly involve subcutis, skeletal muscle and even bone. We share our experience with a novel cutaneous VCL::ALK spindle cell tumor. An 11-year-old male presented with a back pedunculated pink-red papule thought to be a pyogenic granuloma. Biopsy histopathology revealed an epithelial collarette with pedunculated tumor extending to deep dermis/subcutis interface. The combination of spindled and epithelioid cells, an ovoid myopericytoid appearance within myxoid to collagenous stroma, low to moderate MIB1 and focal S100 protein without SOX10 immunostaining, were suggestive of a novel RAS::MAPK tyrosine kinase fusion sarcoma that is well described...

Cutaneous syncytial myoepithelioma is a tumor type that was initially reported in 2013 as a syncytial variant of cutaneous myoepithelioma characterized by intradermal nodular proliferation of oval to spindle-shaped tumor cells in solid and syncytial patterns. Fusion of genes Ewing sarcoma breakpoint region 1 / EWS RNA binding protein 1 (EWSR1) and pre-B cell leukemia homeobox 3 (PBX3) is found in approximately 90% of the cases. We report a case of cutaneous syncytial myoepithelioma with diagnostic difficulty due to folliculocentric morphology and atypical immunohistochemical results, including diffuse positivity of α-smooth muscle actin and claudin 4 and negative immunoreactions for epithelial membrane antigen and S100 protein...

Perineurioma is a benign peripheral nerve sheath tumor. Several subtypes have been described, including plexiform, reticular, and sclerosing. The reticular variant has been previously described as having a net or lace-like growth pattern consisting of large anastomosing cords of spindle-shaped cells. We report a case of an 11-year-old male who presented with a two-year history of a slowly enlarging, tan-white lesion on the finger. Microscopically, the lesion consisted of cells with ovoid nuclei and delicate, elongate cytoplasmic processes, arranged in a microreticular pattern...

Essential thrombocythemia is a chronic myeloproliferative syndrome which usually courses with an asymptomatic excess platelet count. Cutaneous manifestations secondary to microcirculation abnormalities are rare but can represent a helpful diagnostic clue in order to prevent major thromboembolic events. We report two cases of heterogeneous livedoid and "net-like" skin lesions in the context of essential thrombocythemia with identical histopathologic findings (lumina obliteration by eosinophilic material, mostly positive for CD61 platelet stain, without vasculitis of medium-sized skin vessel)...

INTRODUCTION: Glomus tumors (GT) are rare and benign tumors that arise from glomus bodies and usually develop in digital areas. Extradigital GT are exceptional and thigh location is infrequent. CASE REPORT: We report a case of a GT of the thigh in a 79-year-old male patient that measured 9,5 cm in maximum size. GT was above the muscular fascia without infiltrating it. Internal hypervascularity was seen by spectral Doppler ultrasound. Magnetic resonance image showed a heterogeneous mass with hyperintense and hypointense components and internal lobes with liquid-liquid levels...

The lentiginous spread of melanocytes into the hair follicle can be observed in a number of benign melanocytic neoplasms such as in nevi but also in sun-induced melanocytic hyperplasia and melanoma. The follicular colonization by melanocytes in melanoma is classified into three distinct patterns: primary follicular melanoma, melanoma with folliculotropism, and invasive melanoma arising from melanoma in situ with folliculotropism. The role of follicular colonization in melanoma pathologic staging is still a matter of debate though the description of the latter has been recommended by the International Collaboration on Cancer Reporting...

BACKGROUND: Trichorhinophalangeal syndrome type 1 (TPRS1) expression has been found to be highly sensitive and specific for breast carcinomas. The frequency of TRPS1 expression in cutaneous neoplasms like mammary Paget disease (MPD) and extramammary PD (EMPD) is currently unknown. We assessed the utility of TRPS1 immunohistochemistry (IHC) in the evaluation of MPD, EMPD, and their histopathologic mimics, squamous cell carcinoma in situ (SCCIS) and melanoma in situ (MIS). METHODS: Twenty-four MPDs, 19 EMPDs, 13 SCCISs, and 9 MISs were subjected to immunohistochemical analysis using anti-TRPS1 antibody...

INTRODUCTION: Porocarcinoma is a rare, malignant adnexal tumor that recently has been shown to contain YAP1-NUTM1 and YAP1-MAML2 fusion transcripts, with NUT IHC positivity in a subset of these tumors. Consequently, NUT IHC may either aid in the differential diagnosis, or represent a confounding factor depending on the clinical scenario. Here, we present a case of NUTM1 rearranged sarcomatoid porocarcinoma of the scalp presenting as a NUT IHC positive lymph node metastasis. CASE REPORT: A mass was excised from the right neck level 2 region with a lymph node initially diagnosed as metastatic NUT carcinoma with unknown primary site...

BACKGROUND: In order to minimize the risk of incomplete excision of basal cell carcinomas (BCC) the macroscopic tumor margins should be adequately defined. Optical coherence tomography (OCT) is a non-invasive imaging tool that can provide structural and vascular information about skin cancer lesions. The study objective was to compare the pre-surgical delineation of facial BCC by clinical examination, histopathology and OCT imaging in tumors undergoing full excision. METHODS: 10 patients with BCC lesions on the face were examined clinically, with OCT and histopathology at 3 mm intervals, from the clinical lesion border and beyond the resection line...

No abstract text is available yet for this article.

BACKGROUND: Hypereosinophilic syndrome (HES) encompasses a group of diseases with blood hypereosinophilia and eosinophil-mediated organ dysfunction. HES-associated skin abnormalities, termed cutaneous HES (cHES) here, may influence diagnosis of HES. We sought to better define clinical and histopathological features of cHES. METHODS: We retrospectively reviewed clinical records and cutaneous histopathology of adult patients with HES evaluated at our institution from 2007 to 2018...

Microsecretory adenocarcinoma (MSA) is a newly described salivary gland tumor harboring a characteristic balanced chromosomal translocation resulting in MEF2C::SS18 gene fusion. Six primary cutaneous MSA cases have been recently described. We report three additional cases confirming the relevance of this recently identified entity of primary cutaneous adnexal tumor. Three patients aged 53-, 64- and 78-years-old were retrospectively diagnosed with MSA of the skin (MSAS) as consultation cases of the CARADERM (CAncers RAres DERMatologiques) national network...

Cutaneous adverse effects of imatinib are common and well documented in the literature. However, imatinib-induced lichen planus is an uncommon side effect with only four reported cases. In addition, reactivation of hepatitis B is an extremely rare association. We report two cases of imatinib-induced lichen planus, one of which is associated with hepatitis B reactivation, and one case of lichenoid eruption caused by imatinib. The aim of our report is to make physicians aware of this rare association between lichen planus and imatinib...

BACKGROUND: Distinguishing melanocytic pseudonests encountered in lichenoid dermatoses or lichenoid keratoses from melanoma in situ (MIS) with brisk lichenoid inflammation can prove challenging. METHODS: We designed a case-control study to evaluate the accuracy metrics of PRAME immunohistochemistry to distinguish melanocytic pseudonests in lichenoid dermatoses or keratoses from inflamed MIS. Immunostaining for PRAME was performed on paraffin-embedded formalin-fixed diagnostic tissue using a rabbit monoclonal antibody to PRAME (Abcam), with a 1:3200 dilution on a Leica Bond detection system...

The association between acanthosis nigricans (AN) and mycosis fungoides (MF) has rarely been described, but it is known that MF may appear as AN-like vegetating and papillomatous plaques in skin folds, or may be associated with paraneoplastic AN. There have also been recent descriptions of a form of "intertriginous MF" that is characterised by skin fold involvement and the expression of T follicular helper (TFH) markers, and often has an aggressive course. We describe the case of a 48-year-old man affected by MF associated with AN, whose lesions were characterised by a TFH immunophenotype and the expression of the GATA-3 nuclear master regulator that may be related to a TFH-2 sub-population or possible disease progression...

Digital papillary adenocarcinoma (DPA) is a rare neoplasm that can exhibit local recurrence and distant metastasis. We present a series of eight cases of DPA demonstrating two distinct clinical presentations, morphologies, immunophenotypes, and molecular features. Four cases were characterized by painless, slow-growing nodules located on the digits. The lesions were small, well-defined, and confined in the dermis. Histologically, these tumors were composed of glandular structures lined by cuboidal epithelium with luminal papillary infoldings...