Pseudoepitheliomatous hyperplasia in cutaneous T-cell lymphoma. A clinical, histopathological and immunohistochemical study with particular interest in epithelial growth factor expression. The French Study Group on Cutaneous Lymphoma

Application of urine proteomics in the diagnosis and treatment effectiveness monitoring of early-stage Mycosis Fungoides

BACKGROUND

Mycosis fungoides (MF) is the most common type of cutaneous T cell lymphoma. As the early clinical manifestations of MF are non-specific (e.g., erythema or plaques), it is often misdiagnosed as inflammatory skin conditions (e.g., atopic dermatitis, psoriasis, and pityriasis rosea), resulting in delayed treatment. As there are no effective biological markers for the early detection and management of MF, the aim of the present study was to perform a proteomic analysis of urine samples (as a non-invasive protein source) to identify reliable MF biomarkers.

METHODS

Thirteen patients with early-stage MF were administered a subcutaneous injection of interferon α-2a in combination with phototherapy for 6 months. The urine proteome of patients with early-stage MF before and after treatment was compared against that of healthy controls by liquid chromatography-tandem mass spectrometry. The differentially expressed proteins were subjected to Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Clusters of Orthologous Groups analyses. For validation, the levels of the selected proteins were evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

We identified 41 differentially expressed proteins (11 overexpressed and 30 underexpressed) between untreated MF patients and healthy control subjects. The proteins were mainly enriched in focal adhesion, endocytosis, and the PI3K-Akt, phospholipase D, MAPK, and calcium signaling pathways. The ELISA results confirmed that the urine levels of Serpin B5, epidermal growth factor (EGF), and Ras homologous gene family member A (RhoA) of untreated MF patients were significantly lower than those of healthy controls. After 6 months of treatment, however, there was no significant difference in the urine levels of Serpin B5, EGF, and RhoA between MF patients and healthy control subjects. The area under the receiver operating characteristic curve values for Serpin B5, EGF, and RhoA were 0.817, 0.900, and 0.933, respectively.

CONCLUSIONS

This study showed that urine proteomics represents a valuable tool for the study of MF, as well as identified potential new biomarkers (Serpin B5, EGF, and RhoA), which could be used in its diagnosis and management.

Pseudocarcinomatous Hyperplasia Masquerading as a Well-Differentiated Squamous Cell Carcinoma Associated With Primary Cutaneous Anaplastic Large-Cell Lymphoma

ABSTRACT

Pseudocarcinomatous hyperplasia (PCH) is a reactive proliferation of the epidermis associated with CD30 + lymphoproliferative disorders. In this article, we report the case of a 42-year-old man who presented with a 10-year history of a solitary erythematous patch on the right thigh that progressed to an ulcerated, crusted plaque. Histologic examination revealed an infiltrate of atypical CD30 + lymphocytes consistent with primary cutaneous anaplastic large-cell lymphoma with overlying well differentiated keratinocyte hyperplasia akin to a well-differentiated invasive squamous cell carcinoma. This case demonstrates the phenomenon of pseudocarcinomatous hyperplasia mimicking features of invasive squamous cell carcinoma. It highlights the necessity of careful clinical correlation when diagnosing squamous cell carcinomas in younger patients on non-sun-exposed areas and the exclusion of accompanying known causes of pseudocarcinomatous hyperplasia.

Two Histologic Patterns of Lymphomatoid Papulosis Occurring in a Child: A Matter of Timing?

There are several histologic patterns seen in lymphomatoid papulosis, with the possibility of different subtypes occurring in the same patient. We report a case of lymphomatoid papulosis presenting with 2 histologic subtypes (types A and B) occurring concomitantly in a 10-year-old child, and postulate that the different subtypes occur dependent on the age of the lesion biopsied. Incidentally, one of the biopsies also shows a rarely seen pattern of pseudoepitheliomatous hyperplasia in a pediatric lymphomatoid papulosis patient.

Pseudocarcinomatous Hyperplasia, Squamous Cell Carcinoma, and Keratoacanthoma Associated to Lymphomas of the Skin and External Mucous Membranes: A Case Report and Literature Review

Pseudocarcinomatous hyperplasia (PCH) is a benign reactive epithelial proliferation that may be associated to lymphomas of the skin or external mucous membranes. We present a case of single lesion mycosis fungoides (Woringer-Kollop's reticulosis pagetoid) associated with PCH that was initially misdiagnosed as squamous cell carcinoma (SCC) and review all PubMed-indexed previously reported cases on lymphomas of the skin or external mucous membranes associated to PCH, SCC, and keratoacanthomas. Including our own case, we collected data of 114 cases of cutaneous or mucosal lymphoproliferative disorders associated to PCH, 3 cases associated to SCC, and other 3 cases associated to keratoacanthomas. All cases were tabulated to the following parameters whenever data was available: sex, age, previous medical conditions, number of lesions (single × multiple), site of involvement (mucosa, skin or both), clinical impression, initial equivocal histopathologic diagnosis, final diagnosis, keratinocytic atypia (presence × absence), lymphocytic atypia (presence × absence), CD30-status, and treatment.

The Role Played by Growth Factors TGF-β1, EGF and FGF7 in the Pathogeny of Oral Pseudoepitheliomatous Hyperplasia

Pseudoepitheliomatous hyperplasia is an epithelial proliferation that develops in the dermis or lamina propria. It is a lesion associated to another pathology, which appears as a response to a great variety of infectious, neoplastic, inflammatory or traumatic stimuli. The etiopathogeny of this lesion is not clear yet. Therefore, we performed an immunohistochemical study on a group of 20 cases of pseudoepitheliomatous hyperplasia cases associated with inflammatory and neoplastic conditions, by investigating TGFβ1 (Beta growth and transformation factor), EGF (Epidermal growth Factor), and FGF7 (Fibroblast growth factor) expressions during in its development. The TGF-β1 expression was recorded in all the layers of the oral hyperplastic epithelium, going from the basal to the superficial layers, but with a different immunoreactive pattern, according to the region. Our study showed the absence of EGF immunoexpression in the carcinomatous proliferation areas associated to pseudoepitheliomatous hyperplasia and an almost exclusive presence in the hyperplasia lesions associated with inflammatory conditions (in about 30% of the investigated lesions) of a expression varying from poor to moderate for EGF. According to our investigations, we observed the presence of an immunolabeling for FGF7 in 80% of the investigated cases of pseudoepitheliomatous hyperplasia, a maximum of intensity being observed within the cases associated with inflammatory conditions.

Synchronous Occurrence of Primary Cutaneous Anaplastic Large Cell Lymphoma and Squamous Cell Carcinoma

CD30+ lymphoproliferative disorders (LPD) represent a spectrum of T-cell lymphoma including lymphomatoid papulosis and anaplastic large cell lymphoma (ALCL). Epidermis overlying cutaneous CD30+ LPD often shows epidermal hyperplasia, hyperkeratosis, crusting, and ulceration and it is difficult to distinguish from carcinoma such as keratoacanthoma (KA) or squamous cell carcinoma (SCC). Several cases of pseudocarcinomatous hyperplasia mimicking KA or SCC in CD30+ LPD have been reported. The relationship between CD30+ LPD and epithelial proliferations has not yet well understood. It was reported that a variety of mediators, including epidermal growth factor (EGF), transforming growth factor-α and EGFR from CD30+ LPD could attribute to epidermal hyperplasia. However, separate and distinct SCC occurring in CD30+ LPD has rarely been reported. Herein, we present a rare case of coexistence of SCC and cutaneous ALCL located on the same region.

Pseudocarcinomatous Hyperplasia Hiding Lymphomatoid Papulosis

Pseudocarcinomatous hyperplasia (PCH) is a reactive proliferation of the epidermis that can be associated with many inflammatory and neoplastic conditions. Histologically, it is characterized by irregular strands of epidermis, usually at the level of the follicular infundibulum, projecting downward into the dermis. The differentiation between a well-differentiated squamous cell carcinoma and PCH can be particularly challenging when the biopsy is superficial and the causing lesion is dermal-based. Lymphomatoid papulosis (LyP) is an uncommon, self-healing, recurrent, cutaneous T-cell lymphoma, included among the primary cutaneous CD30-positive T-cell lymphoproliferative disorders. LyP is characterized by a chronic course of years to decades that does not compromise survival, even if patients with LyP are at risk for second cutaneous or nodal lymphoid malignancies. LyP and other lymphomas are major neoplastic causes of PCH and can be misdiagnosed or completely overlooked if the PCH is particularly exuberant. We describe the case of an otherwise healthy 55-year-old man who presented with a 3-month history of erythematous papules on upper and lower limbs. A diagnosis of LyP associated with PCH was made after 3 skin biopsies. The propensity of the CD30+ cutaneous lymphoproliferative disorders to an incognito growth pattern is well recognized, and a low-magnification scanning of the histological slides can be an inappropriate approach.

Pseudocarcinomatous hyperplasia in anaplastic large cell lymphoma, a mimicker of poorly differentiated squamous cell carcinoma: report of a case and review of the literature

Pseudocarcinomatous hyperplasia can occasionally be observed in biopsies of CD30-positive lymphoproliferative disorders. It is important to be cognizant of this association, because epithelial hyperproliferation can overshadow large atypical lymphoid cells, leading to an erroneous diagnosis of squamous cell carcinoma (SCC) or keratoacanthoma. Herein, we present a case of anaplastic large cell lymphoma (ALCL) with pseudocarcinomatous hyperplasia simulating a poorly differentiated carcinoma and review the literature on this subject. Immunohistochemical staining with p63 helped delineate the infiltrating tongues of pseudocarcinomatous hyperplasia from the malignant infiltrate. We present this case to raise awareness of the potential for pseudocarcinomatous hyperplasia to occur in the setting of CD30+ lymphoproliferative disorders. Clinicians and dermatopathologists should consider the possibility of ALCL or lymphomatoid papulosis when examining lesions with features of inflamed SCC, especially if the tumor presents on a site or in a patient that is not typical of SCC.

Pseudoepitheliomatous hyperplasia mimicking invasive squamous cell carcinoma in extranodal natural killer/T-cell lymphoma: a report of 34 cases

AIMS

Pseudoepitheliomatous hyperplasia (PEH) is defined as a pattern of epidermal reaction. However, it has not yet been extensively documented in extranodal natural killer/T-cell lymphoma (ENKTL). The aim of our study was to analyse a series of ENKTLs concomitant with PEH mimicking squamous cell carcinoma (SCC).

METHODS AND RESULTS

We analysed 34 cases of ENKTL with PEH. In our study, the incidence of PEH was 3.8% in ENKTLs diagnosed over a 13-year period. All 34 cases presented with PEH, appearing as tongue-like projections of squamous epithelium into the underlying submucosa/dermis with variable depths and jagged borders. The keratinocytes sometimes showed a minor degree of cytological atypia, mostly in the stratum basale, and keratinocyte necrosis was absent. Atypical mitoses and a high nuclear/cytoplasmic ratio were absent. The submucosa and the squamous cell cords were also permeated by atypical lymphocytes.

CONCLUSIONS

ENKTL can be associated with PEH, and the atypical lymphoid cell population can be highly subtle, and therefore may be easily mistaken for SCC, leading to inappropriate therapy. A correct diagnosis requires awareness and recognition of this pitfall by recognizing the associated conditions listed above, which distinguish PEH from SCC.

Pseudocarcinomatous hyperplasia mimicking squamous cell carcinoma in a case of CD56-positive cytotoxic T-cell lymphoma

We present the case of an 84-year-old patient with a cutaneous CD56 positive cytotoxic T-cell lymphoma associated with substantial pseudocarcinomatous hyperplasia mimicking squamous cell carcinoma (SCC). The patient presented with a 7-month history of several progressive, ulcerated plaques on his right forearm. An initial biopsy showed changes consistent with a diagnosis of SCC for which the patient underwent surgical treatment. Several months later, the patient developed recurrent ulcerated plaques on the right forearm of which several biopsies were performed. The biopsies repeatedly showed marked pseudocarcinomatous hyperplasia resembling SCC. Deeper punch biopsies, however, showed a dense superficial and deep infiltrate of markedly atypical lymphocytes. Immunohistochemical analysis revealed strong positive staining for CD3, CD8, CD56 with negative stains for CD30 and Epstein-Barr virus-encoded small non-polyadenylated RNAs (EBER). Staining for beta F1 and gamma-delta T-cell receptor (γδ TCR) were both negative. This constellation was most consistent with a diagnosis of cutaneous peripheral T-cell lymphoma, unspecified in association with marked pseudocarcinomatous hyperplasia. Our case adds cutaneous peripheral T-cell lymphoma, unspecified to the list of conditions associated with pseudocarcinomatous hyperplasia (PCH) and illustrates once again the potential pitfalls of distinguishing marked pseudocarcinomatous hyperplasia from SCC.

Pseudocarcinomatous hyperplasia associated with hidradenoma papilliferum

Cutaneous pseudocarcinomatous hyperplasia is a benign proliferation that can be associated with many nontumoral and tumoral conditions. In the literature, squamous proliferations of different types have been associated with several types of adnexal adenomas. However, we found no reported case of association of hidradenoma papilliferum with pseudocarcinomatous hyperplasia. We had the opportunity of studying this type of an association in a 38-year-old man. The hidradenoma was located deep in the corion of the biopsy and the uppermost squamous epithelium showed a pseudocarcinomatous hyperplasia that focally contacted with the hidradenoma. No atypia was noted in the squamous proliferation. E-cadherin was diffusely expressed by the squamous nests, whereas p53 and Ki-67 were restricted to the basal layer. Cyclin D-1 was expressed in the parabasal layer. Immunohistochemistry of the squamous proliferation was negative for human papillomavirus.

Pseudoepitheliomatous hyperplasia: a review

Pseudoepitheliomatous hyperplasia (PEH) is a benign condition, characterized by hyperplasia of the epidermis and adnexal epithelium, closely simulating squamous cell carcinoma. PEH may be present in a number of conditions characterized by prolonged inflammation and/or chronic infection, as well as in association with many cutaneous neoplasms. Herein, we review different inflammatory, infectious, and neoplastic skin diseases, in which florid epidermal hyperplasia is a prominent histopathologic feature, and introduce a systematic approach in the interpretation of PEH.

Anaplastic large cell lymphoma: twenty-five years of discovery

CONTEXT

The year 2010 commemorates the 25th year since the seminal publication by Karl Lennert and Harald Stein and others in Kiel, West Germany, describing an unusual large cell lymphoma now known as anaplastic large cell lymphoma (ALCL). Investigators at many universities and hospitals worldwide have contributed to our current in-depth understanding of this unique peripheral T-cell lymphoma, which in its systemic form, principally occurs in children and young adults.

OBJECTIVE

To summarize our current knowledge of the clinical and pathologic features of systemic and primary cutaneous ALCL. Particular emphasis is given to the biology and pathogenesis of ALCL.

DATA SOURCES

Search of the medical literature (Ovid MEDLINE In-Process & Other Non-Indexed Citations and Ovid MEDLINE: 1950 to Present [National Library of Medicine]) and more than 20 years of diagnostic experience were used as the source of data for review.

CONCLUSIONS

Based on immunostaining for activation antigen CD30 and the presence of dysregulation of the anaplastic lymphoma kinase gene (2p23), the diagnosis of ALCL has become relatively straightforward for most patients. Major strides have been made during the last decade in our understanding of the complex pathogenesis of ALCL. Constitutive NPM-ALK signaling has been shown to drive oncogenesis via an intricate network of redundant and interacting pathways that regulate cell proliferation, cell fate, and cytoskeletal modeling. Nevertheless, pathomechanistic, therapeutic, and diagnostic challenges remain that should be resolved as we embark on the next generation of discovery.

Tumor proliferation in the right arm

It is a case of fast growth tumor lesion on the posterior region of the right arm of a 37-year-old female patient. Dermatopathological and immunohistochemical characteristics are discussed to support the definite diagnosis.

Primary cutaneous ALCL with phosphorylated/activated cytoplasmic ALK and novel phenotype: EMA/MUC1+, cutaneous lymphocyte antigen negative

Primary cutaneous anaplastic large-cell lymphoma (ALCL) ordinarily is distinguished from systemic ALCL by clinical presentation, absence of anaplastic lymphoma kinase (ALK) expression, and immunophenotype (CLA+, EMA/MUC1-). We present an exceptional case of an elderly man with primary cutaneous ALCL and no systemic disease for a 13-year period. Recurrent skin tumors in this patient were characterized by anaplastic, often multinucleated, cells infiltrating the lymphatics and associated with pseudoepitheliomatous hyperplasia. Cutaneous lymphocyte antigen was absent and EMA/MUC1, typical of systemic ALCL, was strongly expressed by the tumor cells. Remarkably, the tumor cells expressed a cytoplasmic-only variant of ALK protein, as reported in 3 previous cases of primary cutaneous ALCL. Fluorescence in situ hybridization revealed lack of rearrangements of the chromosome 2 ALK gene locus usually involved by translocation t(2;5) or other chromosomal rearrangements that generate nucleophosmin-ALK or the variant ALK fusions that occur in systemic ALCL. Nonetheless, the cytoplasmic ALK protein in the patient's tumor cells was shown to be phosphorylated/activated, suggesting a novel mechanism of ALK activation. Primary cutaneous ALCL of this novel subtype should be distinguished from systemic ALCL to ensure proper clinical management.

Primary cutaneous CD30+ anaplastic large-cell lymphomas mimicking keratoacanthomas

Primary cutaneous anaplastic large cell lymphoma (ALCL) may be associated with keratoacanthoma (KA)-like epithelial hyperplasia and dense eosinophilic and neutrophilic infiltrates. Diagnosis in such cases is challenging both clinically and histologically, because the large atypical lymphoid cells may be obscured by the massive infiltrate of eosinophils and neutrophils, or confused with invasive squamous cell carcinoma or KA. We recently encountered two cases of CD30+ ALCL presenting with a KA-like tumour on the eyelid and nose, respectively. One showed features of KA histologically, with marked tissue eosinophilia and neutrophilia.

T helper type 1 cytokines and keratinocyte growth factor play a critical role in pseudoepitheliomatous hyperplasia initiation during cutaneous leishmaniasis

Pseudoepitheliomatous hyperplasia (PEH) is an exuberant proliferation of the epidermis. The underlying mechanism(s) that lead to PEH have not been completely elucidated. Here, we characterize PEH during the healing stages of cutaneous leishmanial ulcers in mice. During experimental cutaneous leishmaniasis (CL) C57BL/6 mice produce PEH, and BALB/c do not. A series of immunohistochemical and immunological studies were performed to identify the secretory products of PEH regulation. We observed that the distribution of TNF-alpha and IFN-gamma under PEH had a stripe-like diffuse pattern and localized in the upper part of the papillary dermis directly under the proliferating epidermis. Macrophages were identified as the major source of TNF-alpha (56.3%). The importance of IFN-gamma and TNF-alpha in PEH development was proven by the initiation of PEH after three intralesional injections of TNF-alpha and IFN-gamma every three days in infected BALB/c mice. In C57BL/6 mice, keratinocyte growth factor (KGF) expressing cells were found immediately under the basal membrane of the hyperplastic epidermis in comparison with sporadic KGF positive cells deep in the dermis of BALB/c mice. Quantitative RT-PCR analysis demonstrated increased KGF and KGF receptor expression in uninfected C57BL/6 mice as compared to BALB/c mice. These data indicate that Th1 cytokines and KGF play a critical role in PEH initiation during CL.

Cell proliferation and p53 expression in pseudoepitheliomatous hyperplasia of oral paracoccidioidomycosis

Paracoccidioidomycosis (PCMycosis) is a systemic mycosis frequently found in many regions of Latin America. Microscopically, it is characterised by granulomatous inflammation and pseudoepitheliomatous hyperplasia (PEH). This work describes the proliferation index and p53 expression by immunohistochemistry in PEH of PCMycosis, normal oral mucosa (NOM) and mild oral epithelial dysplasia (ED). Ki67 positive cells were present in the basal and parabasal layers in NOM and PEH, while in ED it was also observed in the spinous layer. Percentage of ki67 positive cells was 7.7, 28.2 and 46.0 in NOM, PEH and ED respectively. p53 was negative in NOM and in PEH it was expressed by few cells in the basal layer of only three cases. However, it was expressed in all cases of ED, in basal and parabasal layers. Although histologically PEH mimics well-differentiated squamous cell carcinoma, its proliferative pattern and p53 expression are more similar to NOM than to dysplasia. These findings, confirm PEH as a reactive process probably associated with the underlying chronic inflammation.

Oral malignant melanoma associated with pseudoepitheliomatous hyperplasia. Report of a case

BACKGROUND

Pseudoepitheliomatous hyperplasia (PEH), a histological mimic of squamous cell carcinoma, is an exuberant reactive epithelial proliferation that may be induced by a variety of infectious, traumatic, inflammatory and neoplastic conditions of the skin and mucous membranes. PEH has been described in association with Spitz nevi and intramucosal nevi but not with oral malignant melanoma.

METHODS AND RESULTS

A case of PEH in malignant melanoma of the palate in a 46-year-old female patient has been described. A search of the English literature did not disclose any previously reported case of such event.

CONCLUSIONS

PEH associated with oral malignant melanoma is apparently very rare and most likely originates from the surface epithelium. This is in contrast with PEH in cutaneous melanoma where follicular or eccrine units have been suggested to be the origin.

CD30+ lymphoproliferative disorders: histopathology, differential diagnosis, new variants, and simulators

CD30+ lymphoproliferative disorders of the skin (CD30+ LPD) represent a well-defined spectrum of primary cutaneous T-cell lymphomas which have been recognized as distinct entities in recent lymphoma classifications. Lymphomatoid papulosis and anaplastic large-cell lymphoma share the expression of CD30 antigen as a common phenotypic hallmark but differ in regard to their clinical and histologic features as well as their biologic behavior. This article summarizes the histologic features of CD30+ LPD and presents recently identified new clinicopathologic variants of CD30+ LPD. There is an increasing number of reactive inflammatory disorders and neoplastic diseases which are composed of or contain a significant number of CD30+ cells and mimic LyP or anaplastic large cell lymphoma clinically or histologically. Differential diagnostic considerations focus on other lymphoproliferative processes with CD30+ tumor cells as well as non-lymphoid neoplasms and inflammatory simulators. The term CD30+ pseudolymphoma is proposed to designate inflammatory processes with CD30+ T cells. The final diagnosis of CD30+ LPD is based on a synthesis of clinical, histologic, phenotypic, and molecular genetic findings.

Paratumoral epidermal hyperplasia: a novel prognostic factor in thick primary melanoma of the skin?

There is a lack of histopathological factors to sub-stratify prognosis in pT3/4 melanoma primaries. In the presented pilot study, the prognostic significance of different clinical and histopathological parameters was studied in thick primary melanoma taking paratumoral epidermal hyperplasia (PTEH) into consideration. Of 1632 melanoma patients in the melanoma register of the Martin Luther University Halle-Wittenberg in the years 1980 to 1987, 16 cases with tumor thickness (TT) of the primary > or = 3 mm, documented metastasis-free follow-up of 10+ years after primary therapy and available histologic sections were compared with an adequate recurrence control group (n = 62) by PTEH and standard prognostic parameters. PTEH was demonstrable in 15 of 16 patients of the metastasis-free group (PTEH penetration depth 1.42 +/- 0.82 mm/mean +/- SD) and 27 of 62 of controls (0.29 +/- 0.46 mm), P < or = 0.001. Of the standard prognostic parameters, TT, sex, location, and lack of nevus association also correlated with metastasis. In multivariate analysis, PTEH > or = 1 mm was the single independent parameter with the highest (negative) association to recurrence (odds ratio 52.3). Occurrence of PTEH might predict a more moderate course of disease in thick melanoma. Thus, it might become an easily determinable and effective tool to sub-stratify prognosis in thick primary melanoma of the skin. Further studies are necessary to prove these findings.

Ichthyosiform mycosis fungoides: report of a case associated with IgA nephropathy

We report a case of ichthyosiform mycosis fungoides (MF) associated with IgA nephropathy. Histological examination showed a dense atypical lymphocytic infiltrate admixed with epithelioid cells and giant cells in the dermis associated with the features of epidermotropism and folliculotropism. Reported cases of ichthyosiform MF are reviewed and histopathological characters of ichthyosiform MF are summarized. We suggest a histiocyte/dendritic-cell-rich infiltrate, or granulomatous features of infiltrate may be another characteristic of ichthyosiform MF. This case was associated with IgA nephropathy, which is uncommon. Such a presentation has never been reported in the literature.

Pseudotumorous Folliculotropic Mycosis Fungoides

Fungating nodules and infiltrated plaques are usually equated with advanced tumor stage mycosis fungoides. We report an 85-year-old man who presented in this way but multiple skin biopsies revealed that the bulk of his nodules were due to marked follicular hyperplasia as a result of folliculotropic mycosis fungoides. This clinical presentation may be best described as a pseudotumorous form of mycosis fungoides dominated by follicular epithelial hyperplasia rather than lymphocytic proliferation characteristic of true tumor stage disease. Similar presentations have been described as a verrucous and hyperplastic variant of mycosis fungoides due to the presence of prominent epidermal hyperplasia.

Primary cutaneous CD30+ anaplastic large cell lymphoma with keratoacanthoma-like pseudocarcinomatous hyperplasia and marked eosinophilia and neutrophilia

BACKGROUND

Pseudocarcinomatous hyperplasia (PCH) and marked tissue neutrophilia have been observed in cutaneous CD30(+) anaplastic large cell lymphoma (ALCL) occasionally and may cause misdiagnosis.

METHODS

An unusual case of CD30(+) ALCL of the skin resembling keratoacanthoma (KA) both clinically and pathologically was described. Histologic examination and immunostaining were performed.

RESULTS

A 55-year-old woman presented with a 3-month history of an enlarging hyperkeratotic tumor on the forehead with a central keratinous plug. Microscopic examination showed epithelial hyperplasia resembling KA and a diffuse background infiltrate of large atypical lymphoid cells in the dermis. The atypical cells resembled epithelial cells and were obscured by a massive infiltrate of eosinophils and neutrophils. Immunostaining confirmed the presence of a diffuse infiltrate of CD30(+) cells; these cells were negative for CD45RO, CD20, CD15, epithelial membrane antigen, anaplastic lymphoma kinase-1, and cytokeratin. There was no evidence of extracutaneous involvement. The findings were consistent with primary cutaneous CD30(+) ALCL of null cell phenotype with KA-like epithelial hyperplasia and marked eosinophilia and neutrophilia.

CONCLUSIONS

Our case illustrates that primary cutaneous ALCL may be associated with KA-like PCH and concurrent marked tissue eosinophilia and neutrophilia. Diagnosis in such cases is challenging both clinically and histologically because the large atypical lymphoid cells may easily be obscured by the massive infiltrates of eosinophils and neutrophils or confused with invasive squamous cell carcinoma.

Immunohistochemical evaluation of cell proliferation antigen Ki-67 and apoptosis-related proteins Bcl-2 and caspase-3 in oral granular cell tumor

PURPOSE

We sought to evaluate the cell proliferation activity and immunohistochemical expression of proteins that promote or inhibit apoptosis in oral granular cell tumor (GCT).

STUDY DESIGN

Immunohistochemistry for Ki-67, a cell proliferation marker; Bcl-2, an anti-apoptotic protein; and caspase-3, a protein implicated in the execution of apoptosis, was performed on tissues from 12 patients with GCT of the tongue.

RESULTS

Nuclear immunostaining for Ki-67 was observed only in isolated GCs (less than 2%). All patients exhibited cytoplasmic immunoreactivity for Bcl-2 in the majority of tumor cells. Cytoplasmic staining for caspase-3 was also present in more than 50% of GCs in all tumors.

CONCLUSIONS

GCT cells display low proliferation activity, a finding possibly related to their benign behavior. Caspase-3 expression suggests activation of the apoptotic cascade in the GCs, but persistence of the cells in the tissues could be attributed to the expression of Bcl-2 protein, a molecule that functions as a survival factor.

Pseudoepitheliomatous hyperplasia in lichen sclerosus of the vulva

Small tentacles or separated nests of squamous cells in the dermis are not uncommonly seen in long-standing vulvar lichen sclerosus (LS) associated with epidermal thickening. We recently encountered a case where separated nests of well-differentiated squamous cells in the dermis were difficult to distinguish from squamous cell carcinoma (SCC). Further biopsies showed similar nests originating from every hair follicle. We postulated a diagnosis of multifocal pseudoepitheliomatous hyperplasia (PEH) to explain this phenomenon. Because we could find no reference to PEH in the setting of LS, we reviewed the biopsies of 92 women with extragenital and vulvar LS with and without carcinoma to determine its frequency and histological appearance. The study population, which excluded the index case, comprised 10 women with extra-anogenital LS, 58 with vulvar LS without carcinoma, and 24 with vulvar LS with carcinoma. The presence of PEH, epidermal thickness, predominant dermal collagen change, degree of inflammation, and presence of fibrin and red blood cells were recorded. The presence or absence of lichen simplex chronicus (LSC), squamous cell hyperplasia (SCH), and differentiated vulvar intraepithelial neoplasia (VIN) were recorded. PEH was identified only in vulvar LS, where it was seen in 7/58 (12.1%) women without carcinoma, 1/24 (8.3%) with carcinoma, and 0/10 (0%) with extra-anogenital LS. Two forms of PEH were seen: predominantly epidermal 7/8 (87.5%) and predominantly follicular 1/8 (12.5%). PEH was associated with increased epidermal thickness, less dermal edema, more dermal inflammation, fresh fibrin, and red blood cell extravasation. In all cases, there was associated LSC, but there was no SCH or differentiated VIN. In conclusion, PEH may explain many of the cases of dermal tentacles and separated squamous nests in vulvar LS with LSC. The association with fresh fibrin and red blood cells suggests that PEH might be a reaction to tissue damage. PEH is distinguished from SCC by its lack of atypia, confinement to the abnormal collagen, and limited growth. The pathologist must be careful about making a diagnosis of PEH in LS with epidermal thickening, looking carefully for basal atypia and other features of differentiated VIN in the overlying epidermis or dermal proliferation. We do not know whether PEH occurs in differentiated VIN and, if it does, how it could be distinguished from SCC.

Melanoma associated with pseudoepitheliomatous hyperplasia: a case series and investigation into the role of epidermal growth factor receptor

BACKGROUND

Pseudoepitheliomatous hyperplasia (PEH) is a reactive epithelial proliferation that occurs in response to underlying infectious, inflammatory, and neoplastic conditions. The histologic features of PEH may simulate squamous cell carcinoma and may obscure an underlying malignant process. The association of PEH with benign melanocytic nevi is well described in the literature. However, reports documenting the association of PEH with melanoma are rare.

METHODS

We examined the demographic and histologic features in 13 cases of melanoma in association with PEH. In addition, we evaluated the possible pathogenic role of epidermal growth factor receptor (EGFR) using immunohistochemical methods.

RESULTS

In each case, histologic examination revealed epidermal hyperplasia with irregular cords of well-differentiated epithelial cells extending into the dermis and infiltrating the melanoma. Although overlap existed, two patterns of epidermal hyperplasia were noted. The majority of cases (69%) exhibited acanthosis, hyperkeratosis, papillomatosis, and irregular infiltrating epithelial cords with squamous eddies. The remaining cases demonstrated basaloid acanthosis, laminated orthokeratosis, and horn cysts. EGFR immunohistochemical studies revealed strong staining within the basal layer of the epithelium, with no discernible difference between the hyperplastic epithelium overlying the melanoma cells and adjacent normal skin. Immunostaining among the melanoma cells was absent to weak in each of the cases. All cases exhibited intense EGFR immunoreactivity in macrophages underlying the epidermal lesions.

CONCLUSIONS

Melanoma is capable of presenting in a variety of histologic guises, including a pattern with PEH. The etiology of PEH, as rarely seen in conjunction with melanoma, unlikely involves EGFR and remains to be elucidated.

Pseudocarcinomatous change in lymphomatoid papulosis and primary cutaneous CD30+ lymphoma: a clinicopathologic and immunohistochemical study of 6 patients

We report 6 cases of pseudoepitheliomatous hyperplasia (PEH) mimicking squamous cell carcinoma in association with an atypical CD30+ dermal infiltrate. Three patients had lymphomatoid papulosis type A, and 3 patients had cutaneous CD30+ lymphoma. All 6 cases showed histologic evidence of PEH with keratinocyte atypia. In 4 cases there was significant atypia to prompt a diagnosis of squamous cell carcinoma. Three of these received treatment with wide local excision and 2 had been engrafted. Immunohistochemical staining for epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha) showed similar expression in lesional and perilesional skin. Epidermal growth factor receptor (EGFR) expression by the proliferating epithelium was similar to that of the suprabasal adjacent normal epidermis. There was no aberrant expression of EGF, TGF-alpha, and EGFR by atypical lymphocytes. These cases demonstrate that PEH associated with CD30+ lymphoproliferative disease may closely resemble squamous cell carcinoma, thereby leading to inappropriate diagnosis and treatment.