Acantholytic squamous cell carcinoma: is it really a more-aggressive tumor?

Neoadjuvant therapy for HER2-positive acantholytic squamous cell breast carcinoma: a case report

HER2-positive acantholytic squamous cell carcinoma (ASCC) of the breast is exceptionally rare, and its clinicopathologic features are poorly understood. The impact of neoadjuvant therapy on HER2-positive breast ASCC is unclear. Here we report on a 58-year-old woman who was diagnosed with HER2-positive ASCC of the right breast, who underwent neoadjuvant treatment with albumin-paclitaxel, carboplatin, and trastuzumab, and surgery. Neoadjuvant therapy was effective, with no recurrence or metastasis after 1.5 years of postoperative follow-up.

Mohs micrographic surgery for keratinocyte carcinomas: clinicopathological predictors of the number of stages

Background

The number of Mohs stages needed to remove a keratinocyte carcinoma affects resource use, expenses, and repair complexity. This study aimed to identify clinicopathological predictors associated with increased or decreased stages and areas for further research.

Methods

A retrospective review was conducted from a single private practice with two Mohs surgeons of 2788 consecutive Mohs cases between January 2017 and December 2021, analyzing the average number of stages taken versus national norms (P = 0.21) and subgroups using unpaired t tests (*<0.05).

Results

Several tumor features were significantly associated with fewer stages: squamous cell carcinomas, Mohs appropriate use criteria score of 7 or 8, preoperative size <0.25 cm2, tumors on the lips and extremities (including hands/fingers), and smoking. Clinicopathological features significantly associated with more stages included Mohs appropriate use criteria score of 9, recurrent skin cancers, basal cell carcinomas, tumor size of 2.25-3.99 cm2, cancers on ears, solid organ transplant patients, treatment delays >180 days, and patients ≥90 years old.

Conclusions

Significant predictors exist for both increased and decreased numbers of Mohs micrographic surgery stages required to eradicate a tumor, which may help Mohs surgeons facilitate, plan, and allocate resources more effectively. Areas for further research in Mohs micrographic surgery are identified.

Acantholytic Squamous Cell Carcinoma Arising From Lichen Sclerosus: A Rare Case Affecting Vulvar Skin

We present the case of an 82-year-old female with acantholytic squamous cell carcinoma affecting vulvar skin. The patient had a history of perineal lichen sclerosus for 5 years before presentation. She was referred to a dermatologist for intractable severe pain associated with the lesions. Biopsies showed an infiltrative squamous cell carcinoma with histology consistent with the acantholytic subtype. Acantholytic squamous cell carcinoma is a rare histologic variant characterized by dyscohesive keratinocytes with pseudoglandular formation and dyskeratosis. It is associated with sun-damaged skin and most commonly occurs in the head and neck of elderly men. Few cases have been reported at nondermal sites and non-sun-exposed dermis. The patient underwent a radical vulvectomy and bilateral inguinal node dissection. The 1.6 cm tumor was diffusely acantholytic and pseudoglands were present. The tumor cells were diffusely positive for p63 immunohistochemical stain. As expected at this site, there was no solar elastosis identified histologically. However, vulvar intraepithelial neoplasia and chronic lichen sclerosus were apparent. This case represents a rare histologic subtype of squamous cell carcinoma in an unusual site associated with lichen sclerosus instead of solar elastosis.

Intra-oral Acantholytic Squamous Cell Carcinoma: 55 Cases. Is this Variant more Aggressive?

We aimed to collect and analyze available cases of intraoral acantholytic squamous cell carcinoma (aSCC), that consisted of the authors' cases and cases derived from the existing literature, with an emphasis on the pathological staging and patient outcome. Our research question was whether aSCC is more aggressive than conventional SCC. The literature was searched for documented cases of aSCC involving the intra-oral mucosa, excluding those from the lips and tonsils, and seven new cases were added from our files. The authors compared the obtained aSCC data to existing data for conventional SCC. Fisher Exact or Pearson's χ² tests were used for categorical variables. Fifty-five cases of intraoral aSCC were reviewed, of which 48 were retrieved from the literature. Analysis of the published cases was reinforced by contacting the authors of all the papers with incomplete data for further clarifications. The most common sites of aSCC were the tongue (24/55) and the maxilla/maxillary gingiva and/or palate (11/55). The overall survival rate was 36/53 (67.9%) with a mean follow-up period of 22 months against 62.5% for conventional SCC (p = 0.6). No statistically significant difference between the two variants of the tumor with respect to the oral cavity was detected. The differences in age, sex, survival rate, staging, and locations were not statistically significant. Based on the available data from 55 cases, there is no evidence to suggest that aSCC is more aggressive than conventional SCC in intraoral cases.

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.

Treatment-resistant actinic keratoses are characterized by distinct clinical and histological features

BACKGROUND

Actinic keratoses (AK) are generally treated to reduce the risk of progression into invasive cutaneous squamous cell carcinoma (cSCC). However, this risk of transformation is low, and rather than focusing on these lesions, current treatment studies report on complete clearance of AKs in an entire field. This study aimed to investigate treatment-resistant AKs (trAK) after field therapy compared to randomly chosen AKs prior to treatment.

METHODS

AKs were clinically assessed according to the grade of hyperkeratosis and pain on palpation, prior to treatment. TrAKs were biopsied and compared to AKs which were biopsied prior to any treatment. AKs were evaluated regarding histological severity (AKI-III), their basal growth grading (PROI-III), acantholysis, elastosis, follicular extension of atypical keratinocytes and accompanying infiltrate.

RESULTS

Two hundred eleven AKs in 171 patients were identified. TrAKs (N.=79) were significantly more painful (64.6% vs. 22.0%; P<0.0001), showing acantholysis (57.0% vs. 33.3%; P=0.0007); and with distinct basal proliferation (PROIII) (64.4% vs. 46.2%; P=0.0099) compared to the control group (N.=132). In a multivariate analysis using logistic regression, pain and PRO III graded lesions were significant independent (P<0.0001 and P=0.0179) predictors for trAKs. Focusing on individual histological features in the trAK group, AKs with grade AKIII, PROIII or follicular extension reaching the sebaceous gland were the most common findings with 51.9%, 64.6%, and 59.5% AKs demonstrating this, respectively.

CONCLUSIONS

TrAKs are often painful, showing a distinct basal proliferation (PROIII) and acantholysis. As these features are also seen in invasive cSCCs, trAKs may represent a subgroup of AKs and, for this reason, it requires further evaluations.

Palate Squamous Cell Carcinomas:A Ten-Year Single Institute Experience

The literature date estimated that about 5% of all oral cavity cancers are hard palate cancers while soft palate cancers account for about 5-12% of oropharyngeal cancers. Although rare, usually these tumors had a more aggressively behavior than other oral cancer sites. That is why our study aimed to investigate comparatively the epidemiological, clinical and histopathological peculiarities of the two palatal sites of oral squamous cell carcinomas. We conducted a retrospective study limited to a period of 10 years in a single medical institution to investigate the morphoclinical profile of such tumors. We found that patients with hard palate SCCs had an average age slightly larger compared to those who developed soft palate tumors. Also, those with hard palate tumors are mostly diagnosed in less advanced stages compared to those at the level of the soft palate, and implicitly the former had a longer survival time. Histopathologically the most encountered hard palate SCC were the conventional well-differentiated tumor, and from the peculiar SCC variant the papillary and verrucous forms while for the soft palate SCC prevailed the moderate and poor differentiated conventional SCC and from the peculiar SCC variant the basaloid and acantholytic forms. In conclusion hard palate tumors differ in many aspects from those of the soft palate, and thus specification of the origin tumor site become important for the assessment of prognosis, treatment and survival outcome of such patients.

Characteristic imaging findings of acantholytic squamous cell carcinoma: a case report

Acantholytic squamous cell carcinoma (ASCC) is an uncommon, histopathologically distinct variant of squamous cell carcinoma. ASCC commonly occurs in areas of skin exposed to sunlight and has only rarely been seen on mucosal surfaces such as the oral cavity. Although the World Health Organization has defined ASCC as an original entity, the imaging findings of ASCC have not been adequately described. We herein report a case of ASCC occurring in the oral mucosa with emphasis on the findings of several imaging studies: panoramic radiography, intraoral radiography, contrast-enhanced computed tomography, magnetic resonance imaging, and fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography.

Early invasive squamous cell carcinoma recurrence rates: A study examining surgical margins, tumor surface diameter, invasion depth, and grade of differentiation in 1296 cases over 9 years

BACKGROUND

Invasive squamous cell carcinoma (SCC) is typically treated by surgical excision.

METHODS

Consecutive SCC excisions were reviewed prospectively in a single Australian center from 2009 to 2017. Cases were examined for recurrence by histopathologic margins, microscopic tumor surface diameter, invasion depth, grade of differentiation, and anatomic site.

RESULTS

Over 9 years, 1296 cases were collected. By grade of differentiation maximum average microscopic surface diameters ranged from 8.0 to 9.6 mm and maximum average depths from 1.3 to 2.5 mm. Minimum average histopathologic margins for well, moderate, and poorly differentiated SCC, respectively, were 1.4, 1.1, and 1.3 mm. Recurrence occurred in 1.7% of well (n = 18/1084), 1.8% moderate (n = 3/165) and 6.4% in poorly differentiated (n = 3/47) SCC. No recurrence occurred beyond a histopathologic margin of 3.5 mm for well and 2.5 mm for moderately differentiated SCC. Highest recurrence for well-differentiated SCC by anatomic site was the lip (7.0%) then ear (4.6%).

CONCLUSION

We found a recurrence rate of 1.0% for histopathologic margins of 1.5 mm with early well-differentiated SCC. The grade of differentiation and anatomic site had a larger influence on recurrence rates compared to the histopathologic margins. Poorly differentiated SCC and ear or lip sites require wider surgical margins.

Acantholytic Squamous Cell Carcinoma and Salivary Duct Carcinoma Ex-pleomorphic Adenoma of the Submandibular Gland: A Report of Two Extremely Rare Cases with an Immunohistochemical Analysis

Carcinoma ex pleomorphic adenoma (CXPA) is a malignant tumor of the salivary gland that arises from pleomorphic adenoma (PA). Squamous cell carcinoma (SCC) is extremely rare in the salivary glands. We report two cases of acantholytic SCC (ASCC) ex PA. Case 1 involved a 72-year-old female, and case 2 involved a 67-year-old male. Histologically, both cases involved PA, and salivary duct carcinoma (SDC) components, which were positive for androgen receptor (AR) and gross cystic disease fluid protein (GCDFP)-15 but negative for HER2, were seen in the intracapsular regions. The invasive components consisted of ASCC, which were positive for cytokeratin 5/6 and p63 but negative for AR and GCDFP-15. The SDC and ASCC components were positive for the epidermal growth factor receptor. In both cases, the cytoplasmic localization or decreased expression of E-cadherin was observed in the ASCC. In the early phase, CXPA might emerge as SDC, and it might change into SCC as it invades beyond the capsule due to changes in microenvironment. Also, the aberrant expression of E-cadherin is related to acantholysis in SCC.

Acantholytic squamous cell carcinoma of the lung with marked lymphogenous metastases and high titers of myeloperoxidase-antineutrophil cytoplasmic antibodies: a case report

BACKGROUND

Acantholytic squamous cell carcinoma (ASQCC), histologically characterized by intercellular bridge loosening, is recognized as a rare variant of squamous cell carcinoma (SQCC). ASQCC may demonstrate a worse prognosis than conventional SQCC. Pulmonary ASQCC is particularly rare; its biological behavior and prognostic data have not been reported.

CASE PRESENTATION

We report the clinical and autopsy findings of a 71-year-old Japanese man with pulmonary ASQCC. Pulmonary lesions, suggestive of idiopathic interstitial pneumonia, were radiologically observed 3 and 6 years prior to the patient's most recent hospitalization; however, the patient did not undergo further medical examinations. Upon being discovered unconscious, the patient was admitted to our hospital. Dehydration and lower limb muscle weakness were noted, as were laboratory findings of coagulation abnormalities and renal dysfunction. Computed tomography helped confirm a 21-mm peripheral nodule in the upper left lobe of the lung, with associated swollen lymph nodes in the bilateral hilar, mediastinal, and para-aortic regions. Brain and spinal lesions, suggestive of neurological disturbances, were not found. Small cell lung carcinoma was suspected, upon admission, but high serum levels of squamous cell carcinoma antigen and cytokeratin-19 fragments were present. Therefore, advanced lung cancer, possibly SQCC, was diagnosed. The patient was treated with best supportive therapy, and died one month after admission. Hypercalcemia and high serum levels of parathyroid hormone-related protein (PTHrP) and myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) titers were observed. Progressive renal insufficiency was absent due to improved renal function subsequent to hydration. An autopsy helped confirm the left lung tumor as an ASQCC associated with pulmonary lymphangitic carcinomatosis and multiple metastases in the lungs and lymph nodes. Skin lesions suggesting malignant tumors were absent. The metastatic lesions consisted largely of acantholytic tumor cells, and the lungs showed usual interstitial pneumonia pattern; vasculitis was absent.

CONCLUSIONS

This is the first reported case of pulmonary ASQCC resulting in an aggressive clinical course, with marked lymphogenous metastases and PTHrP-associated hypercalcemia. The high serum MPO-ANCA titers were clinicopathologically insignificant, but may have been related to the pulmonary interstitial lesion. Pulmonary ASQCC represents a highly malignant subset of lung cancer.

Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is a malignant neoplasm of the skin characterized by an aberrant proliferation of keratinocytes. Cutaneous SCC is the second most common malignancy globally, and usually arises in the chronically sun-damaged skin of elderly white individuals. From a pathologist's perspective, it is important to differentiate cSCC from the benign and reactive squamoproliferative lesions and identify the high-risk features associated with aggressive tumor behavior. In this article, we provide an up-to-date overview of cSCC along with its precursor lesions and important histologic variants, with a particular emphasis on the histopathologic features and molecular pathogenesis.

Update from the 4th Edition of the World Health Organization of Head and Neck Tumours: Tumours of the Oral Cavity and Mobile Tongue

There have been several additions and deletions in Chapter 4 on Tumours of the oral cavity and mobile tongue in the 2017 fourth edition of the World Health Organization Classification of Tumours of the Head and Neck. This chapter excludes the oropharynx, which now is a stand-alone chapter acknowledging the uniqueness of the oropharynx from the oral cavity. New entries in Chapter 4 include rhabdomyoma, haemangioma, schwannoma, neurofibroma and myofibroblastic sarcoma in the section titled Soft tissue and neural tumours. Discussion of salivary gland entities have been reduced and includes mucoepidermoid carcinoma and pleomorphic adenoma as the other salivary gland types are discussed elsewhere. In the Haematolymphoid tumours section, like the salivary gland section, only tumors that commonly present in the oral cavity are discussed in Chapter 4. Excluded entities in the updated classification include papillary hyperplasia, median rhomboid glossitis, keratoacanthoma, focal oral mucinosis, and secondary tumors. This article will summarize the changes in the new classification since the 2005 edition focusing on selected entities that have had significant changes along with new entries.

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.

Decreased expression of intercellular adhesion molecules in acantholytic squamous cell carcinoma compared with invasive well-differentiated squamous cell carcinoma of the skin

Intercellular adhesion proteins are poorly characterized in acantholytic squamous cell carcinoma (ASCC), a more aggressive tumor than nonacantholytic invasive well-differentiated squamous cell carcinoma (SCC) of the skin. In this study we compared expression of Dsg3, E-cadherin, and syndecan-1 in ASCC and SCC. Immunohistochemical detection of Dsg3, E-cadherin, and syndecan-1 in 22 ASCCs and 22 SCCs was graded on a semiquantitative scale for intensity of staining (SI) and degree of circumferential staining (CS) about the cell membrane. Results were assessed by means of conditional logistic regression and χ(2) analysis. Dsg3 and E-cadherin expression (SI, CS) was significantly decreased (P < .05) in ASCC compared with SCC, whereas staining for syndecan-1 was similar in the 2 tumor types. Differences in expression of adhesion markers between ASCC and SCC may contribute to the development of acantholysis in ASCC and its more aggressive biologic behavior.