Acantholytic squamous cell carcinoma mimicking epithelioid angiosarcoma: A diagnostic challenge by cytology.

Squamous cell carcinoma (SCC) is the most common malignancy of the head and neck region. Most cases present little diagnostic difficulty on fine needle aspiration (FNA), but unusual variants can be problematic. The authors report a case of the acantholytic SCC of the oral cavity in a 36-year-old male. The FNA showed hypercellularity, with malignant cells arranged in isolation, loosely cohesive groups and a linear configuration. Such cells were round to elongated, with vesicular nuclei and prominent nucleoli. Cells possessed occasional intracytoplasmic vacuoles, misinterpreted on FNA to be vasoformative features as seen in malignant endothelial cells. The cytologic diagnosis was "positive for malignancy, suggestive of angiosarcoma". A total excision was performed and by histology, the tumor was diagnosed as acantholytic SCC. The malignant cells were positive by immunostaining for AE1/AE3, p40, p63 and vimentin, but negative for CD31, CD34 and ERG. The intracytoplasmic vacuoles were PAS- and mucin-negative and negative for the above antibodies. Testing for HPV (molecular and p16 immunostaining) was negative. This case highlights the diagnostic challenges on cytology when malignant acantholytic squamous cells show intracytoplasmic vacuoles, and stresses how immunohistochemistry is important for distinguishing acantholytic SCC from other mimics.

Acantholytic oral squamous cell carcinoma with clear cell change - a rare amalgamated variant.

Background: Acantholytic squamous cell carcinoma (ASCC) is an uncommon histological variation of oral squamous cell carcinoma (OSCC), accounting for fewer than 4% of all occurrences. The tumor shows a slight masculine predisposition, with the lower lip being the most commonly affected location. ASCC is reported to have a diverse biologic behavior, which explains its ability to metastasize to distant places and, thus, its poor prognosis. Similarly, clear cell change in OSCC is a rare occurrence with an unknown etiology that suggests its aggressive nature. Method and Results: Histopathology reveals central acantholytic cells with numerous duct-like features. The presence of distinct cytological atypia contributes to the diagnosis of SCC. Special stains and IHC aid in distinguishing tumor from other histopathologically similar entities. Conclusion: The case of a 29-year-old male presented here with an updated literature review highlights the need for histological study of the unique and seldom seen oral ASCC with clear cell change, which can be ignored because of similarities with other entities. Because recurrence rates are so high for ASCC, amalgamated clear cell change makes it critical for proper treatment initiation with a definite diagnosis. To the best of our knowledge, this is the first documented occurrence. Our experience with the present case suspected a more aggressive behavior due to a high Ki-67 index, anticipating a poorer prognosis in the oral cavity considering the patient's young age.

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.

Acantholytic Squamous Cell Carcinoma: a Diagnostic Pitfall on Cytology.

Acantholytic squamous cell carcinoma is an infrequent subtype of squamous cell carcinoma. This tumour variant being rare in itself has been rarely described at the penile location, thus leading to a limitation on information of pathological and immunohistochemical findings and prognosis. Clinical observations indicate an aggressive biologic behaviour. The cytological features on fine-needle aspiration cytology samples have rarely been described in literature. It is imperative for pathologists to be aware of the cytological features so as to allow the distinction of this variant from conventional squamous carcinoma. Here, we explore an intriguing case of a metastatic tumour to inguinal lymph node with the primary lesion at the penis which constituted a diagnostic challenge on cytological examination.

Acantholytic oral squamous cell carcinoma with clear cell change - a rare amalgamated variant

ABSTRACT Background Acantholytic squamous cell carcinoma (ASCC) is an uncommon histological variation of oral squamous cell carcinoma (OSCC), accounting for fewer than 4% of all occurrences. The tumor shows a slight masculine predisposition, with the lower lip being the most commonly affected location. ASCC is reported to have a diverse biologic behavior, which explains its ability to metastasize to distant places and, thus, its poor prognosis. Similarly, clear cell change in OSCC is a rare occurrence with an unknown etiology that suggests its aggressive nature. Method and Results Histopathology reveals central acantholytic cells with numerous duct-like features. The presence of distinct cytological atypia contributes to the diagnosis of SCC. Special stains and IHC aid in distinguishing tumor from other histopathologically similar entities. Conclusion The case of a 29-year-old male presented here with an updated literature review highlights the need for histological study of the unique and seldom seen oral ASCC with clear cell change, which can be ignored because of similarities with other entities. Because recurrence rates are so high for ASCC, amalgamated clear cell change makes it critical for proper treatment initiation with a definite diagnosis. To the best of our knowledge, this is the first documented occurrence. Our experience with the present case suspected a more aggressive behavior due to a high Ki-67 index, anticipating a poorer prognosis in the oral cavity considering the patient's young age.

Adenosquamous Carcinoma with the Acantholytic Feature in the Oral Cavity: A Case Report and Comprehensive Literature Review.

Adenosquamous carcinoma (ASC) is an aggressive subtype of squamous cell carcinoma (SCC). Due to its poor prognosis, a precise pathological diagnosis of ASC is essential but challenging because its pathological criteria are still unclear. Here, we present a rare case of oral ASC accompanied by acantholytic features. The tumor was raised in the mandibular gingiva and recurred locally approximately 13 months after the initial surgery with cervical lymph node metastasis. Pathological specimens of the primary lesion showed acantholysis in a large area of the SCC. Mucous cells, the characteristic finding indicating glandular differentiation, were imperceptible in the initial surgical specimen but increased in the locally recurrent and metastatic lymph node specimens. In a comprehensive literature review of oral ASC cases, the present case was the only case of ASC with acantholytic features. We reconfirmed that ASC has poor prognoses, such as low 5-year overall survival and disease-free survival, high locoregional recurrence, and high distant metastasis rates. A precise diagnosis of ASC is required for estimating prognosis and undergoing close follow-up, even if the adenocarcinomatous component is limited to a small area in the lesion.

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.

Pseudovascular adenoid squamous cell carcinoma of the tongue: a case report and literature review.

Pseudovascular adenoid squamous cell carcinoma (PASCC) is an uncommon histologic variant of squamous cell carcinoma, characterized by acantholysis in the cancer nests resulting in a pseudovascular appearance, and a subtype of acantholytic squamous cell carcinoma. It is relatively common in sun-exposed skin, but is extremely rare in oral cavity. A 56-year-old woman was referred to our department presented with a fast-growing mass in the front of the tongue for more than two months. Physical examination revealed a exophytic lesion with a pedicle in the anterior tongue. An incisional biopsy was performed. On microscopic examination, the tumor was composed of vessel-like anastomosing channels and dilated vessel-like spaces, similar to hemangioma, and the anastomosing channels contained free tumor cells. The nests of tumor cells with significant acantholysis were observed in some regions. Immunohistochemical examination revealed cells positive for pan-CK, CK5/6, p63, and negative for CD31 and CD34. The pathological diagnosis was confirmed as pseudovascular adenoid squamous cell carcinoma. The extended resection of the tumor and neck dissection was performed. There was no tumor recurrence or distant metastasis after 15 months of follow-up.

Oral variant of acantholytic squamous cell carcinoma-Histochemical and immunohistochemical features.

Acantholytic squamous cell carcinoma (ASCC) is an uncommon variant of squamous cell carcinoma (SCC). It is characterized by a combination of typical SCC and pseudoglandular structures, dyskeratotic cells and prominent acantholysis. The purpose of this study was to analyze the histochemical and immunohistochemical characteristics of the intraoral variant of ASCC. Cases of intraoral ASCC were retrieved from the English language literature. Four new cases from our files were added. In total, 35 cases were included and analyzed in this study. The mean age of the patients was 61.5 + 13 years (age range 38-92 years), with a male-to-female ratio of 1.7:1. According to the available data, histochemical and immunohistochemical stains for mucins were found to be consistently negative. E- cadherin, a marker of adherens junctions, was usually reported to be expressed in areas of "typical" (non acantholytic) SCC, but reduced in the acantholytic areas. We examined for the first time the expression of claudin 1, a marker of tight junctions, and found it to be reduced in the acantholytic areas, similar to E-cadherin. Several cases of oral ASCC also expressed vimentin and cytokeratin (CK) 19, markers associated with epithelial-mesenchymal transition. A wide range of non-epithelial markers yielded negative immunoreactions. In conclusion, ASCC is an uncommon variant of squamous cell carcinoma. The acantholytic process appears to involve reduced expression of molecular components of both adherens junctions and tight junctions. These findings could suggest a relation to the epithelial mesenchymal transition process and therefore further studies are needed in order to establish such a link and the subsequent possible impact on the clinical outcome of the patients.

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.

How phenotype guides management of non-conventional squamous cell carcinomas of the larynx?

Although the majority of laryngeal malignancies are the conventional squamous cell carcinomas (SCC), a wide variety of malignant epithelial tumors can affect the larynx. Current treatment guidelines are designed to guide clinicians in management of conventional laryngeal SCC. Less is known about the biological behavior and responsiveness to therapy and overall outcomes of other malignant epithelial lesions. Because a spectrum of disease biology is represented by these rare phenotypes, an understanding of the basic biology can help direct management to optimize clinical outcome in this group of patients. This review provides a critical analysis of literature relating to the diagnosis, management, and outcome of patients with non-conventional squamous malignant epithelial neoplasms of the larynx. Particular attention is paid to features which are at variance with the conventional SCC and how these impact on management of these rare tumors.

Acantholytic invasive squamous cell carcinoma: tumor diameter, invasion depth, grade of differentiation, surgical margins, perineural invasion, recurrence and death rate.

BACKGROUND: Squamous cell carcinoma (SCC) may present with or without the feature of acantholysis. METHODS: Investigate invasive acantholytic SCC by microscopic maximum tumor surface diameter, depth of invasion, grade of differentiation, perineural invasion (PNI) and percentage of acantholysis. Assess recurrence following excision. RESULTS: A total of 1658 consecutive invasive SCC cases were examined, comprising 4.9% acantholytic SCC. Median tumor microscopic maximum diameter was 8 mm for acantholytic SCC and 7.3 mm for non-acantholytic SCC. Median tumor invasion depth was 1.0 mm for acantholytic SCC and 1.5 mm for non-acantholytic SCC. Well, moderate and poor differentiation were not significantly different between acantholytic SCC and non-acantholytic SCC. One PNI case was found in 82 acantholytic SCC cases. A total of 77 acantholytic SCC cases were followed up over a median 25 months finding histologic proven recurrence at three acantholytic SCC excision sites. CONCLUSIONS: Acantholytic SCC were more likely to be located on head sites with less median depth than non-acantholytic SCC. Increasing percentage of acantholysis within acantholytic SCC was not associated with a shift towards poor differentiation. Histologic margins of 1.2 mm may adequately excise small acantholytic SCC. No recorded deaths, low PNI and low recurrence rates suggests acantholytic SCC is low-risk.

Primary cutaneous adenosquamous carcinoma of the penis: the first characterization of HPV status in this rare and diagnostically challenging entity with review of glandular carcinomas of the penis.

Glandular and pseudoglandular tumors of the penile skin are extremely uncommon and can present diagnostic challenges. Primary adenosquamous carcinoma of the penis is an extremely rare tumor, composed of distinct areas of malignant squamous and glandular cells, making it a diagnostically challenging entity. The World Health Organization (WHO) recognizes several subtypes of squamous cell carcinoma (SCC), each with its own distinctive pathologic appearance, clinical associations and prognosis. Among these variants is the exceedingly uncommon adenosquamous carcinoma (ASC), representing 1%-2% of all SCC of the penis. Recent large studies have interrogated the presence of human papillomavirus (HPV) in malignant penile tumors and have shown specific morphologic patterns and clinical presentations to associate with HPV status. However, given the rarity of the adenosquamous variant of SCC, it has largely been excluded from these studies. The glandular components of these lesions can present a confusing appearance, particularly when a large tumor is represented on a small biopsy. Here we describe a difficult histologic presentation of this rare tumor, with the first published characterization of the HPV status of this subtype. This case represents a distinctly unusual case of metastatic HPV-positive primary cutaneous adenosquamous carcinoma of the penis.

Acantholytic Squamous Cell Carcinoma on the Right Foot / 대한피부과학회지

Acantholytic squamous cell carcinoma is a well-defined, rare variant of squamous cell carcinoma in which significant portions of the neoplastic tissue show, on microscopy, a pseudoglandular or tubular pattern. It usually presents in aged patients as an erythematous nodule with scales, crust, and ulceration on sun-exposed areas. Herein we report a case of acantholytic squamous cell carcinoma that occurred on the Rt 4th toeweb of a 70-year-old man.