Incidental acantholysis

Acantholytic Nodular Basal Cell Carcinoma

ABSTRACT

Acantholysis is a microscopic finding describing the breakdown of desmosomes of keratinocytes and the formation of intraepithelial clefts after the loss of cohesion of keratinocytes. It can be observed in keratinocytic neoplasms, typically actinic keratoses and squamous cell carcinomas, and defines the acantholytic variants of these entities. Acantholysis has so far been reported in only 4 cases of basal cell carcinomas (BCCs), mainly of the superficial type. A case of an otherwise typical nodular BCC showing features of acantholysis is presented here. Because BCCs are keratinocytic neoplasms, the finding of acantholysis in them is not totally surprising; however, the reason why it is only very exceptionally observed in BCCs is unclear.

Clinical and histopathological evaluation of 50 acantholytic cutaneous squamous cell carcinomas: Analysis outcome in a retrospective case-control study

BACKGROUND

Acantholytic cutaneous squamous cell carcinomas (aCSCCs) have been classically considered as a high-risk variant of CSCC. However, more recent studies show that aCSCC does not confer more aggressiveness. This study aims to establish whether the prognosis of the aCSCC is worse than that of the non-acantholytic (naCSCC) or not.

METHODS

Retrospective case-control study with 50 aCSCCs and 50 naCSCCs. For each aCSCC, an naCSCC with similar high-risk features to the aCSCC but with no acantholysis was selected. Prognosis between both groups was compared.

RESULTS

The mean age was 86 years (SD 9.61). Sixty-one patients were men. Thirty-nine CSCCs were located in high-risk head and neck areas. Twenty CSCCs exhibited a poor degree of differentiation, and 36 showed an infiltrative growth pattern. The tumor diameter was 18.71 mm (interquartile range, IQR 35), and the tumor thickness was 6.72 mm (IQR 15.50). Twelve CSCCs exhibited perineural infiltration, and eight CSCCs exhibited invasion beyond the subcutaneous fat. Positive margins after excision of the tumor in 22 aCSCCs vs eight naCSCCs (P < 0.02). Nineteen poor-prognosis events were observed (local recurrence, lymph node metastasis, and death from CSCC). However, no differences were observed between both groups when comparing poor-prognosis events.

CONCLUSION

The proportion of unfavorable events is similar in aCSCC and naCSCC. The acantholytic histopathological subtype is not associated with a poorer prognosis than the non-acantholytic CSCC in our cohort.

Incidental Acantholysis in Hailey-Hailey Disease (Microscopic Nikolsky Sign): An Underappreciated Histologic Sign

Identification of subtle disease-specific histologic changes may be of significant help in early diagnosis of acantholytic skin diseases. Hailey-Hailey disease (HHD) is an autosomal dominant genodermatosis characterized by vesiculoerosive lesions favoring the intertriginous areas. Histologically, HHD is characterized by full-thickness acantholysis of the spinous layer in association with dyskeratosis of individual keratinocytes; a pemphigus vulgaris-like suprabasal pattern of acantholysis may be observed in the earliest stages of disease. HHD is characterized by highly variable expressivity regarding the age at onset and severity of the disease. Patients may present with late-onset and/or only mild disease. We report the recurrent presence of incidental foci of variably extensive, subclinical acantholysis in multiple bioptic specimens taken from a patient with known HHD for dermatologic conditions other than HHD. Such histologic finding has gone underappreciated in the literature, despite being a likely frequent occurrence in skin biopsies from HHD patients; recognition of this finding might represent a valuable diagnostic clue in selected cases of HHD.

Acantholytic squamous cell carcinoma is usually associated with hair follicles, not acantholytic actinic keratosis, and is not "high risk": Diagnosis, management, and clinical outcomes in a series of 115 cases

BACKGROUND

Acantholytic squamous cell carcinoma (aSCC) is regarded as a high-risk variant of cutaneous squamous cell carcinoma (SCC). Acantholytic actinic keratosis (aAK) has been regarded as a precursor risk factor for aSCC. However, supporting evidence is limited.

OBJECTIVE

We sought to document clinical features, histologic features, management, and outcomes in a series of aSCC cases.

METHODS

Definitions of aSCC, aAK, and aSCC arising in association with aAK were applied to a consecutive series of aSCC cases. Clinical characteristics and outcomes were obtained from electronic medical records.

RESULTS

Of 115 aSCC cases (103 patients, mean age 71.8 years), actinic keratosis was present in 23% (27/115) but only 7.8% (9/115) exhibited associated aAK. Ten cases (10/115, 9%) fulfilled strict histologic criteria for follicular SCC as previously defined, but 50 of 115 (43%) of our aSCC cases exhibited predominant involvement of follicular epithelium rather than epidermis. Clinical outcome (median follow-up, 36 months) was available in 106 of 115 (92%). One patient experienced regional extension (parotid), and 1 patient experienced a local recurrence (nose). No disease-related metastases or deaths were documented.

LIMITATIONS

This was a single-institution retrospective study from the United States.

CONCLUSIONS

The presence of acantholysis in cutaneous SCC does not specifically confer aggressive behavior, a finding that may inform clinical practice guidelines.

Incidental cutaneous reaction patterns: epidermolytic hyperkeratosis, acantholytic dyskeratosis, and hailey-hailey-like acantholysis: a potential marker of premalignant skin change

Focal acantholytic dyskeratosis (FAD), epidermolytic hyperkeratosis (EHK), and Hailey-Hailey-like acantholysis (HH) represent unique histology reaction patterns, which can be associated with defined phenotypic and genotypic alterations. Incidental microscopic foci demonstrating these patterns have been identified in skin and mucosal specimens in association with a gamut of disease processes. These changes, when secondary, are of unclear etiology and significance. The following study further analyzes the incidence and association of these histologic patterns in a routine pathology/dermatopathology practice.

The role of histopathology in the diagnosis of dermatophytoses / Značaj patohistološkog nalaza u dijagnostici dermatofitoza

Histopathological analysis is not a routine procedure for diagnosing fungal skin infections. In the histopathological specimens, fungi are visible only when using special stain such as periodic acid-Schiff (PAS). However, histopathological analysis may not be performed in small laboratories. Histopathological characteristics of fungal skin infections are not specific. In all skin biopsy cases, obtained without clinical suspicion of fungal infection, the knowledge of certain, most frequent histopathological reaction patterns, as well as specific histopathological indicators (a diagnostic histopathological “clue”), of certain superficial mycoses e.g., dermatophytoses, may raise a suspicion of fungal infection and warrant a fungal-specific staining. A retrospective analysis of all PAS-stained sections was carried out. All PAS-positive biopsy specimens were assessed for clinical features, histopathological patterns of skin reactions, and presence of histopathological indicators. Our results have shown that out of the total of 361 PAS-stained sections, fungal hyphae were identified in 12 (3.3%) specimens. In 5 (1.4%) cases, the diagnosis of fungal infection was suspected on clinical grounds, while in 7 (1.9%) cases detection of fungi was an unexpected finding. The most frequent type of histopathological pattern was spongiotic, and the most frequent histopathological indicator was the presence of neutrophils within the epidermis. Our results confirm that dermatophytoses may present with clinical and histological non-specific findings. PAS staining represents a relatively cheap and simple fungal-specific staining. It has been suggested that it not only confirms that the selected material is actually invaded, but also reduces the number of false-negative direct reports, where fungi are cultured from a microscopically negative specimen. Apart from a small percentage of positive findings, our results justify the need for routine PAS staining of all clinically and histologically non-specific inflammatory skin conditions.

Changes of epidermodysplasia verruciformis in benign skin lesions: the EV acanthoma

Foci of histological changes of epidermodysplasia verruciformis (EV) were noted in five benign skin lesions. These skin lesions included an intradermal nevus, a pigmented seborrheic keratosis, an isolated papule on the forearm, a perianal lesion, and an acantholytic acanthoma. Because the changes resembled true EV so strongly despite the absence of clinical EV in these patients, we searched for EV-human papilloma virus (HPV) types in these skin lesions. Polymerase chain reaction (PCR) analysis on the formalin-fixed, paraffin-embedded blocks was performed. As a positive control, we included tissue from two HIV-positive patients with clinical EV proven by biopsy. Studies were also performed on five other archived biopsies that did not show changes of EV on multiple tissue sections. A nested PCR method detected EV-HPV types in three of the five benign skin lesions showing EV changes as well as in the positive controls. EV changes and EV-HPV can be found incidentally on biopsy in the absence of clinical EV; when such changes are the major histopathological finding in an isolated skin lesion, the lesion should be termed an EV acanthoma.

The periodic acid-Schiff stain in diagnosing tinea: should it be used routinely in inflammatory skin diseases?

BACKGROUND

The clinical presentation of tinea is usually, but not always, characteristic. The purpose of this study was to determine whether the routine use of the periodic acid-Schiff (PAS) stain in inflammatory skin disorders is requisite for identifying clinically undiagnosed tinea cases and to ascertain whether there are histopathologic clues that suggest the diagnosis of a dermatophyte infection.

METHODS

Hematoxylin and eosin (H&E)-stained slides from 60 PAS-positive tinea cases were examined histologically by two observers. One observer, aware of the diagnosis of tinea, searched for hyphal elements and also recorded in detail epidermal, dermal, and follicular changes. The second observer, not aware of the diagnosis beforehand, reviewed the same slides, together with randomly mixed slides from 21 non-tinea cases, recording the same parameters as the first reviewer.

RESULTS

Of the 60 cases of tinea, only 45% were diagnosed clinically. Histologic examination of H&E sections by the two observers disclosed the presence of hyphal elements in 68 and 45%, respectively. No significant histologic differences, except for the presence of hyphae, were observed between tinea and non-tinea cases.

CONCLUSIONS

The finding that only 57% of PAS-positive cases of tinea showed hyphal elements on H&E examination alone, together with no other differentiable histologic characteristics, lends strong support for the routine use of PAS-staining for inflammatory skin disorders.

A localized variant of paraneoplastic pemphigus: acantholysis associated with malignant melanoma

We report a 72-year-old male patient with a nodular malignant melanoma that was associated with focal suprabasal acantholysis (FSA). This phenomenon, which is regarded as an incidental finding by dermatopathologists, may be associated with inflammatory and also neoplastic skin diseases. Haematoxylin and eosin stained sections from an erythematous plaque surrounding the patient's tumour showed FSA, direct immunofluorescence (DIF) and indirect immunofluorescence (IIF) on normal human skin, monkey oesophagus and rat urinary bladder were negative. On electron microscopy few desmosomes could be detected in the basal cell layer of the acantholytic areas and there was a nearly complete loss of these structures in the spinous cell layer. Only remnants of cytoplasmic plaques and keratin filaments could be observed in those areas. In contrast, adherens junctions appeared to be well preserved. An enzyme-linked immunosorbent assay (ELISA) using recombinant fusion proteins as antigens did not show circulating autoantibodies against desmoglein 1 (Dsg1) or desmoglein 3 (Dsg3). In contrast, immunoblotting revealed autoantibodies directed against keratinocyte antigens with a molecular weight of 85 kDa and 250 kDa, the first band corresponding to the molecular weight of comigrating plakoglobin. Immunoprecipitation with patient serum also revealed a 85-kDa band. We conclude that these autoantibodies, probably in conjunction with cofactors produced by the tumour, could play a part in the pathogenesis of this variant of FSA, for which we propose the term 'localized paraneoplastic pemphigus.'

Transient acantholytic dermatosis (Grover's disease): a global perspective

Twenty-six years have passed since Grover first described transient acantholytic dermatosis. Since then, the concept of Grover's disease has been expanded to include persistent acantholytic dermatoses as well. Although its origin remains unknown, it may result from an isomorphic response to excessive heat, sweating, or xerosis. It is currently classified as a nonfamilial, non-immune-mediated, acantholytic disorder.

Verruciform xanthoma of the penis with acantholytic cells

Verucciform xanthoma is an unusual lesion characterized by verrucous epithelial proliferation accompanied by a prominent replacement of the dermal papillae with foamy histiocytes. We describe a case of verruciform xanthoma on the glans penis. The most striking histopathological finding was the presence of numerous acantholytic cells in the upper layers of the epithelium. We discuss the differential diagnosis with other acantholytic disorders of the genital area and conclude that our findings can be interpreted as an additional example of incidental acantholysis.