Mucocutaneous Pseudoepitheliomatous Hyperplasia: A Review

Vegetative Pyoderma Gangrenosum Mimicking Squamous Cell Carcinoma: A Poorly Recognized Diagnostic Challenge

ABSTRACT

Pyoderma gangrenosum (PG) is a rare inflammatory neutrophilic dermatosis that is difficult to diagnose due to non-specific clinical, laboratory, and histopathologic features. Distinguishing pseudoepitheliomatous hyperplasia (PEH) from squamous cell carcinoma (SCC) is also histopathologically challenging. The connection between PEH and PG is not well recognized, and instances of PG mimicking SCC are rare. We report a case of vegetative PG accompanied by PEH, originally mistaken for SCC. A 78-year-old woman presented with a 3-month history of an ulcerated, exophytic, and painful mass on her right lower leg. An incisional biopsy revealed PEH and neutrophilic microabscesses, initially raising concerns for SCC keratoacanthoma type with PEH or well-differentiated, infiltrative SCC. However, following additional review of clinical and histopathologic findings at the cutaneous oncology tumor board, the diagnosis of vegetative PG with associated PEH was favored. This case highlights the significance of recognizing PEH as a histopathology feature that can be seen in PG and lead to difficulty distinguishing PG with PEH from SCC. We stress the importance of promptly diagnosing PG through clinical and histopathologic correlation to prevent diagnostic delays and unnecessary surgeries or treatments.

Incidence of Pseudoepitheliomatous Hyperplasia in Oral Granular Cell Tumors of Adults: An Independent Retrospective Analysis Utilizing a Novel Definition

Background: As most biopsy specimens are diagnosed by interpretation of glass slides, the diagnostic process is heavily reliant on subjective interpretation. Granular cell tumors have a widely reported incidence of a pathological phenomenon termed pseudoepitheliomatous hyperplasia. Aim: The study's primary focus was to determine the incidence of pseudoepitheliomatous hyperplasia in granular cell tumors in adults using a novel definition. Methods: A review of the existing literature provided a foundation for a novel definition of pseudoepitheliomatous hyperplasia. Two oral pathology laboratories' archived material were queried to yield 70 specimens matching inclusion criteria. Two board certified Oral and Maxillofacial Pathologists were employed as observers, calibrated on the novel definition using control specimens, and then a blind review was performed. Statistical analyses were performed via Kappa statistical agreement and Fischer's 2-way exact tests. Results: Use of the novel definition resulted in agreement in 97.4% of specimens. The Kappa agreement was 0.939 with a standard error of 0.043 and a 95% confidence interval from 0.856 to 1.0. Landis and Koch's standards for strength of agreement was "almost perfect." Pseudoepitheliomatous hyperplasia was found at a rate of 36.8%. Women made up 79.4% of the study population and the average age was 45 years. Intraorally 91.8% of lesions occurred on the tongue and buccal mucosa. And 93.30% of lateral tongue granular cell tumors occurred in women. Conclusion: Using a definition prior to evaluating subjective histologic criteria resulted in "almost perfect" interobserver statistical reliability. Our definition of pseudoepitheliomatous hyperplasia proved to be reliable and should be further tested.

Hypertrophic Lichen Planus and Hypertrophic Skin Lesions Associated with Histological Lichenoid Infiltrate: A Case Report and Literature Review

Hypertrophic lichen planus (HLP) is a chronic inflammatory skin condition defined by verrucous, pruritic, papules and plaques usually affecting the lower limbs. The diagnosis of HLP is primarily clinical. However, due to its feasible generalized presentation and similarities with other hypertrophic cutaneous disorders, histological evaluation is often necessary. Many dermatological conditions that present with a hypertrophic clinical appearance can arise from a histological lichenoid infiltrate (HCLI). Hence, we provide an overview of the clinical, histopathological, and prognostic features of selected HCLI, including HLP, hypertrophic lichenoid dermatitis, hypertrophic lichen sclerosus (HLS), lichen simplex chronicus (LSC), squamous cell carcinoma (SCC), keratoacanthoma (KA), pseudoepitheliomatous hyperplasia (PEH), viral warts, and lupus erythematosus/lichen planus (LE/LP) overlap. Choosing the appropriate procedure and the anatomical site for an incisional biopsy requires thoughtful consideration to ensure sufficient depth and improve diagnostic accuracy by identifying the histological features specific to each hypertrophic condition.

Pseudocarcinomatous Hyperplasia of the Nose and Necrotic Tracheitis Associated with Acute Myeloid Leukemia

A 29-year-old woman who had been diagnosed with acute myeloid leukemia presented with persistent grade-4 febrile neutropenia (FN) after initial chemotherapy with idarubicin and cytarabine. Despite intensive treatment, FN persisted. Subsequently, her nose became reddish and swollen, obstructing the nasal cavities. Computed tomography revealed swelling of the nostrils and an irregular tracheal surface. Debridement of the nasal lesion and a bronchoscopic biopsy of the tracheal lesion were also performed. A histopathological examination revealed pseudocarcinomatous hyperplasia (PCH) of the nose and necrotizing tracheitis. Both nasal PCH and necrotizing tracheitis ameliorated when the patient recovered from leukocytopenia.

Diagnostic Challenges during Inflammation and Cancer: Current Biomarkers and Future Perspectives in Navigating through the Minefield of Reactive versus Dysplastic and Cancerous Lesions in the Digestive System

In the setting of pronounced inflammation, changes in the epithelium may overlap with neoplasia, often rendering it impossible to establish a diagnosis with certainty in daily clinical practice. Here, we discuss the underlying molecular mechanisms driving tissue response during persistent inflammatory signaling along with the potential association with cancer in the gastrointestinal tract, pancreas, extrahepatic bile ducts, and liver. We highlight the histopathological challenges encountered in the diagnosis of chronic inflammation in routine practice and pinpoint tissue-based biomarkers that could complement morphology to differentiate reactive from dysplastic or cancerous lesions. We refer to the advantages and limitations of existing biomarkers employing immunohistochemistry and point to promising new markers, including the generation of novel antibodies targeting mutant proteins, miRNAs, and array assays. Advancements in experimental models, including mouse and 3D models, have improved our understanding of tissue response. The integration of digital pathology along with artificial intelligence may also complement routine visual inspections. Navigating through tissue responses in various chronic inflammatory contexts will help us develop novel and reliable biomarkers that will improve diagnostic decisions and ultimately patient treatment.

Peristomal Pseudoverrucous Lesions: A Rare Skin Complication of Colostomy

A 56-year-old female patient with colostomy presented with skin-colored cobblestone and verrucous asymptomatic papules on her peristomal skin for three months; she was referred to dermatology. Histopathology revealed irregular acanthosis, tongue-like extension of rete ridges of mature squamous epithelium without atypical morphology, hyperkeratosis, and inflammation of the skin. The histopathologic appearance was evaluated as compatible with pseudoepitheliomatous hyperplasia. No signs of malignancy, fungus, or koilocytes were found. The lesions were diagnosed as pseudoepitheliomatous hyperplasia by clinical and histopathologic findings. In this case report, we review pseudoepitheliomatous hyperplasia associated with colostomy.

Pseudoepitheliomatous hyperplasia of the auricle: two case reports and experiences of reconstruction

BACKGROUND

It is rare to find pseudoepitheliomatous hyperplasia (PEH) on the auricle. PEH should be differentiated from squamous cell carcinoma (SCC). Diagnosis is made after surgery as a biopsy is often inconclusive. A free or pedicled skin flap is needed to avoid deformation of the auricle.

METHODS

Adjacent pedicled skin flap is a good option for reconstruction. Moreover, it was shown how to repair the wound in the following two cases.

RESULTS

The flaps grew well after surgery, and the wound healed well.

CONCLUSION

PEH is a benign lesion. Adjacent pedicled skin flap is a good option for reconstruction, which can avoid deformation of the auricle.

Usage of negative pressure wound therapy in pseudoepitheliomatous hyperplasia secondary to burn injury: a case series

Pseudoepitheliomatous hyperplasia (PEH) is a reactive epithelial proliferation secondary to a wide range of stimuli, including traumatic injury, inflammation, infection, and tumors of the skins. PEH secondary to burn injury is rarely reported. We report 3 cases of PEH patients after burn injury. All three cases were confirmed with the existence of bacterial infection, and all these cases were second or third degree burns. All 3 patients were treated with negative pressure wound therapy after wound debridement or tangential excision. All the wounds healed without split-thickness skin grafting and recurrence.

The role of α-smooth muscle actin in confirming the microinvasion of laryngeal squamous cell carcinoma

BACKGROUND

The diagnosis of microinvasive laryngeal squamous cell carcinoma (LSCC) is not always straightforward and sometimes can be very challenge in daily clinical practice. The focus lies in the confirmation of microinvasion. Cancer-associated fibroblasts (CAFs), as the major element of reactive tumor stroma, are believed to participate actively in the growth and invasion of tumor cells.

OBJECTIVES

To evaluate the diagnostic role of α-smooth muscle actin (α-SMA) labelling CAFs in microinvasive LSCC.

METHODS

A total of 81 laryngeal biopsy specimens were retrieved, including 41 cases of microinvasive LSCC with depth of invasion no more than 3 mm, 20 laryngeal squamous intraepithelial lesion (SIL), and 20 benign pseudoepitheliomatous hyperplasia (PEH). All cases were stained for immunohistochemistry, using antibody against the α-SMA antigen. The correlation between the presence of CAFs in microinvasive LSCC and tumor histological characteristics was investigated.

RESULTS

Immunoreactivity of α-SMA was detected in twenty-nine microinvasive LSCC (29/41, 71%), while no reactivity was observed in laryngeal SIL (0/20, 0%), and rarely in PEH (2/20, 10%). The α-SMA expression pattern in stroma of microinvasive LSCC was significantly different from that of SIL (χ² = 26.966, p = 0.000) and PEH (χ² = 19.838, p = 0.000). In addition, there seemed to be a certain correlation between the histological characteristics of microinvasive LSCC and the presence of interstitial CAFs.

CONCLUSIONS

This study highlights the practical role of utilizing α-SMA in the pathological diagnosis of microinvasive LSCC, with emphasis on variable histomorphologic features of microinvasive LSCC.

Doubly Misdiagnosed: Exophiala Masquerading as Squamous Cell Carcinoma and Chromoblastomycosis

ABSTRACT

Deep cutaneous fungal infections (DCFI) can arise in the setting of skin trauma and immunosuppression. DCFI may be secondary to chromoblastomycosis, which is typically characterized by pseudoepitheliomatous hyperplasia histologically and can be mistaken for squamous cell carcinoma. In addition, "copper penny" spore-like pigmented yeast forms on Grocott's methenamine silver stain can suggest chromoblastomycosis, but this finding is not specific. By contrast, phaeohyphomycosis characteristically exhibits circumscribed pseudocyst or abscess on histopathology, and both yeast and hyphae can be seen. Our case reports a DCFI with pseudoepitheliomatous hyperplasia and "copper penny" yeast forms, ultimately diagnosed as phaeohyphomycosis after isolating Exophiala spinifera on fungal culture.

Case Report: Squamous Cell Carcinoma Referred for Mohs Surgery Found to be Cutaneous Leishmaniasis

Chronic skin lesions constitute a clinical diagnostic challenge. We report the case of a patient whose facial lesion was histopathologically compatible with squamous cell carcinoma and hence programmed for Mohs surgery. However, review of the clinical and epidemiological history led to laboratory diagnosis of cutaneous leishmaniasis, treatment with miltefosine, and complete resolution of the lesion.

Pseudoepitheliomatous Hyperplasia of the Larynx Requiring Total Laryngectomy

Patient: Male, 57

Final Diagnosis: Pseudoepitheliomatous hyperplasia

Symptoms: Dysphonia

Medication: —

Clinical Procedure: Progressive speudoepitheliomaous hyperplasia spreaded

Specialty: Oncology

Histopathological Study of Oral Pseudoepitheliomatous Hyperplasia

ABSTRACT: Pseudoepitheliomatous hyperplasia, also called Heck’s disease, is an epithelial, inconstant and conjunctive proliferation that develops as a response to a great variety of stimuli. It is a lesion associated to different diseases, being found in the following etiopathogenic conditions: infectious pathogenic conditions, tumoral pathogenic conditions, inflammatory pathogenic conditions. We studied oral pseudoepitheliomatous hyperplasia for which we performed a histopathological study, on a group of 47 cases of oral pseudoepitheliomatous hyperplasias, where we investigated the following: oral epithelium changes, changes in the underlying lamina propria and associated etiopathogenic conditions. The main changes of the oral epithelium were: elongation of the epithelial apexes (17.02%), acanthosis (100%), dyskeratosis (14.89%), and in the underlying lamina propria: fibrosis (29.78%), inflammatory infiltrate (70.21% and vascular proliferation (10.64%). The most frequent associated etiopathogenic conditions were the infectious ones (55.31%), followed by the tumoral ones (29.79%), on the last place being the inflammatory conditions (14.89%).

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.

Lesions With an Epidermal Hyperplastic Pattern: Morphologic Clues in the Differential Diagnosis

In this report, we review the most common entities that show a epidermal hyperplastic pattern in the biopsy. These entities include inflammatory, reactive, infectious, hamartomatous, and tumoral conditions, each with a very different prognosis. Therefore, an approach based on the classic "patterns and clues" tools used in dermatopathology can bring a lot of information to the dermatopathologist or the general pathologist evaluating these lesions.

Immunohistochemical findings and differential diagnosis of papillary-type cutaneous verrucous carcinoma of the neck: A case report

Verrucous carcinoma (VC) is a rare subtype of squamous cell carcinoma, with the majority of cases occurring in the oral cavity and genital area. The present study describes a rare case of cutaneous VC of the neck manifesting as a semi-pedunculated multinodular protrusion. Histological analysis revealed thickening of the epidermis and papillary growth. Although cellular atypia was generally mild, a large number of mitoses were observed, of which a small number were abnormal. Additionally, bulbous subepidermal invasion was observed. The lesion was differentiated from papillary squamous cell carcinoma, another rare subtype of squamous cell carcinoma, based on the presence of epidermal verrucous growth and the lack of remarkable nuclear atypia. Benign disorders, including seborrheic keratosis, fibroepithelial polyp, verruca vulgaris and pseudocarcinomatous hyperplasia, were also differentiated from the lesion. Immunohistochemical analysis of cytokeratin (CK)10 expression revealed attenuated staining of the lesion, therefore, anti-CK10 immunohistochemistry may be valuable in the diagnosis of VC.

Oral plexiform schwannoma with unusual epithelial induction

Rare epithelial structures in benign nerve sheath tumors are almost always glandular in appearance. We describe a case of intraoral plexiform schwannoma with concurrent squamous epithelial hyperplasia. The lesion occurred as a pigmented nodule on the gingiva of a 35-year-old woman with no systemic involvement. Histologically, unencapsulated, plexiform fascicular proliferations of schwann cells could be traced from the submucosa to the lamina propria, finally making direct contact with heavily pigmented, elongated rete ridges of the overlying epithelium. Also noted was a schwannian network centered on clustered odontogenic epithelial rests of mature squamous-type, the number and size of which had markedly increased. Impressive immunoprofiles of periepithelial neural microfascicles included the complete absence of axon and perineurium and the unexpected presence of endoneurial fibroblasts. The repertoire of epithelial changes was in a confined area with no extension beyond, supporting hyperplasia induction by an underlying/surrounding schwannoma.

Pseudoepitheliomatous hyperplasia after diode laser oral surgery. An experimental study

Background

To examine the process of epithelial reparation in a surgical wound caused by diode laser.

Material and Methods

An experimental study with 27 Sprage-Dawley rats was undertaken. The animals were randomly allocated to two experimental groups, whose individuals underwent glossectomy by means of a diode laser at different wattages, and a control group treated using a number 15 scalpel blade. The animals were slaughtered at the 2nd, 7th, and 14th day after glossectomy. The specimens were independently studied by two pathologists (blinded for the specimens’ group).

Results

At the 7th day, re-epithelisation was slightly faster for the control group (conventional scalpel) (p=0.011). At the 14th day, complete re-epithelization was observed for all groups. The experimental groups displayed a pseudoepitheliomatous hyperplasia.

Conclusions

It is concluded that, considering the limitations of this kind of experimental studies, early re-epithelisation occurs slightly faster when a conventional scalpel is used for incision, although re-epithelisation is completed in two weeks no matter the instrument used. In addition, pseudoepitheliomatous hyperplasia is a potential event after oral mucosa surgery with diode laser. Knowledge about this phenomenon (not previously described) may prevent diagnostic mistakes and inadequate treatment approaches, particularly when dealing with potentially malignant oral lesions.

Key words:Diode laser, animal model, oral biopsy, oral cancer, oral precancer, pseudoepitheliomatous hyperplasia.

Pseudoepitheliomatous hyperplasia secondary to allergic contact dermatitis to Grevillea Robyn Gordon

We report a case of pseudoepitheliomatous hyperplasia (PEH) in a 55-year-old woman following allergic contact dermatitis (ACD) to Grevillea Robyn Gordon. We believe this to be the first reported case of PEH secondary to ACD, and postulate that this was an exaggerated response to severe ACD as a result of a lack of topical treatment.

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.

Differentiating cutaneous squamous cell carcinoma and pseudoepitheliomatous hyperplasia by multiplex qRT-PCR

Squamous cell carcinoma is the second most common cutaneous malignancy. The diagnosis can occasionally be difficult as there are many lesions that are mimics, clinically and on pathologic examination. One of the most challenging lesions to differentiate from squamous cell carcinoma is pseudoepitheliomatous hyperplasia, a reactive proliferation of the epidermis that can be encountered secondary to a variety of inflammatory and neoplastic conditions. Utilizing the data set from our previously performed DNA microarray studies on formalin-fixed and paraffin-embedded tissue, we found that the genes C15orf48 and KRT9 had a distinct and robust gene expression pattern in distinguishing squamous cell carcinoma from pseudoepitheliomatous hyperplasia. C15orf48 had higher expression than KRT9 in squamous cell carcinoma, but lower expression than KRT9 in pseudoepitheliomatous hyperplasia. We developed and blindly validated a multiplex TaqMan PCR assay that utilizes these two highly discriminatory genes, which can be performed on material extracted from formalin-fixed and paraffin-embedded tissue. The TaqMan assay was able to differentiate squamous cell carcinoma from pseudoepitheliomatous hyperplasia in 54 of 58 cases (93%). Squamous cell carcinoma was accurately identified in 27 of 28 cases (96%); pseudoepitheliomatous hyperplasia in 27 of 30 cases (90%). This multiplex TaqMan PCR assay may be used as a helpful ancillary molecular diagnostic test to accurately distinguish squamous cell carcinoma from pseudoepitheliomatous hyperplasia in challenging cases.