Cytopathology of benign sebaceous salivary gland neoplasia: Comparison of two analogous yet dissimilar entities.

INTRODUCTION: Benign sebaceous salivary gland (SG) neoplasms represent approximately 0.2% of all salivary gland neoplasms. Not only are fine needle aspiration (FNA) biopsy findings of sebaceous adenoma (SA) and sebaceous lymphadenoma (SLA) limited, but their findings are also rarely compared with one another. MATERIALS AND METHODS: Our cytopathology files were searched for examples of benign sebaceous SG neoplasms with concomitant histopathological verification. FNA biopsy and cell collection were performed using standard technique. RESULTS: One case each of parotid SA and parotid SLA showed markedly dissimilar cytomorphology. The SA case was composed of a repetitive population of profusely multivacuolated polygonal cells with single and multiple nuclei, and was specifically recognised cytologically as a sebaceous neoplasm due to its characteristic cytoplasmic vacuolisation. The SLA case, however, was characterised by smears filled primarily with lymphocytes and only scant widely scattered basaloid cell clusters. A non-specific diagnosis of basaloid neoplasm was rendered. In retrospect, recognition of sebaceous differentiation was limited to rare cell groups. CONCLUSION: Though nominally, epidemiologically, and to a degree histopathologically analogous, the cytopathology of SA and SLA are markedly dissimilar, reflecting the dominant cell component in each. With FNA biopsy, a specific interpretation is more likely for SA than SLA due to the overwhelming obscuring lymphoid population in the latter.

Poorly differentiated cutaneous apocrine carcinomas: histopathological clues and immunohistochemical analysis for the diagnosis of this unusual neoplasm.

Primary cutaneous apocrine carcinoma (PCAC) is a rare cutaneous malignancy that is derived from apocrine glands. Histologically, these tumours can appear well-differentiated where diagnosis should be relatively straightforward. However, occasionally these tumours can exhibit high-grade features, and in such instances the diagnosis can be challenging. A retrospective analysis of 12 cases of poorly differentiated PCAC, obtained from large academic institutions, was performed, and summarised below. Immunohistochemical studies were performed in all cases with antibodies against CK7, p63, CAM 5.2, GCDFP-15, GATA3, CEA, PR, ER, HER2, calponin, SMA, androgen receptor and EMA. All 12 cases were poorly differentiated; however, there were some histopathological clues to the diagnosis of apocrine carcinoma; namely, the presence of focal glandular formation, acrosyringial involvement and the presence of single 'pagetoid' cells within epidermis. All tumours were consistently positive for CK7, GATA3 and GCDFP-15 and negative for p63. The tumours had variable expression of CAM5.2, CEA, ER, PR, HER2, androgen receptor and EMA. In three cases, there was a preservation of the myoepithelial cell layer (with calponin and SMA), which also confirmed the primary cutaneous origin. PCAC is a difficult neoplasm to diagnose, as it can appear identical to metastatic carcinomas. We describe 12 cases of poorly differentiated PCAC, highlighting their salient clinical, histopathological and immunohistochemical features, and discuss the potential diagnostic pitfalls in distinguishing this entity from other malignant neoplasms. Our results indicate that a combination of thorough histological inspection coupled with an adequate battery of immunohistochemical stains is necessary to support the diagnosis of PCAC.

Digital Pathology Initiatives and Experience of a Large Academic Institution During the Coronavirus Disease 2019 (COVID-19) Pandemic.

CONTEXT.­: Pathology practices have begun integrating digital pathology tools into their routine workflow. During 2020, the coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged as a pandemic, causing a global health crisis that significantly affected the world population in several areas, including medical practice, and pathology was no exception. OBJECTIVE.­: To summarize our experience in implementing digital pathology for remote primary diagnosis, education, and research during this pandemic. DESIGN.­: We surveyed our pathologists (all subspecialized) and trainees to gather information about their use of digital pathology tools before and during the pandemic. Quality assurance and slide distribution data were also examined. RESULTS.­: During the pandemic, the widespread use of digital tools in our institution allowed a smooth transition of most clinical and academic activities into remote with no major disruptions. The number of pathologists using whole slide imaging (WSI) for primary diagnosis increased from 20 (62.5%) to 29 (90.6%) of a total of 32 pathologists, excluding renal pathology and hematopathology, during the pandemic. Furthermore, the number of pathologists exclusively using whole slide imaging for primary diagnosis also increased from 2 (6.3%) to 5 (15.6%) during the pandemic. In 35 (100%) survey responses from attending pathologists, 21 (60%) reported using whole slide imaging for remote primary diagnosis following the Centers for Medicare and Medicaid Services waiver. Of these 21 pathologists, 18 (86%) responded that if allowed, they will continue using whole slide imaging for remote primary diagnosis after the pandemic. CONCLUSIONS.­: The pandemic served as a catalyst to pathologists adopting a digital workflow into their daily practice and realizing the logistic and technical advantages of such tools.

Anogenital syringocystadenocarcinoma papilliferum in situ or anaplastic extramammary Paget disease? A unifying concept and review of the literature.

Extramammary Paget disease (EMPD) is a rare cutaneous malignancy that typically involves the genital skin and can be primary or associated with an underlying internal malignancy. The typical histopathological appearance of EMPD consists of single or small aggregates of cells with abundant pale cytoplasm and large pleomorphic nuclei, known as Paget cells, scattered throughout the epidermis. We report a case of anogenital EMPD occurring in a 53-year-old man with unusual histopathologic findings of marked epidermal acanthosis, acantholysis, intraepidermal glandular differentiation, and prominent plasma cell-rich fibrovascular cores. These features were entirely confined to the epidermis and adnexa with no evidence of dermal invasion or underlying systemic disease. We review and summarize the literature for atypical features noted in EMPD and summarize similar findings previously described under a variety of descriptions including anaplastic EMPD, anogenital syringocystadenocarcinoma papilliferum in situ (SCACPIS), SCACPIS-like changes in EMPD, and EMPD mimicking acantholytic squamous cell carcinoma in situ. We propose that these features represent a single entity and be considered under a unifying diagnosis to facilitate recognition of this entity.

Merkel Cell Carcinoma of the Maxillary Sinus: An Unusual Presentation of a Common Tumor.

Merkel cell carcinoma is most commonly seen in the skin of sun exposed areas, particularly the head and neck and is associated with Merkel cell polyomavirus. Merkel cell carcinoma at an extracutaneous mucosal site of the head and neck is rare. We report a case of a 74-year-old women who presented with an enlarging thyroid mass found to be neuroendocrine carcinoma consistent with Merkel cell carcinoma (positive for synaptophysin, chromogranin, CK20). Subsequent work up revealed a maxillary sinus mass with extension into the nasal cavity. Biopsy was diagnostic for Merkel cell carcinoma (positive for synaptophysin, chromogranin, CK20 and Merkel cell polyomavirus). There are only case reports and small case series of Merkel cell carcinoma arising in the mucosal sites of the head and neck most commonly in the oral cavity, rarely the sinonasal mucosa. Merkel cell carcinoma metastasizing to the thyroid has only been reported in three other case reports, all from skin primaries. In addition to our case, we review the literature of extracutaneous sinonasal Merkel cell carcinoma and metastases to the thyroid.

An unexpected paradox: wall shear stress in the aorta is less in patients with severe atherosclerosis regardless of obesity.

BACKGROUND: Obesity is a widespread condition that is more prevalent in Western countries compared to others. Aortic atherosclerosis (AA) is a condition that frequently has been associated with obesity. An obesity paradox, where morbidly obese decedents had either no or minimal AA compared to nonobese decedents, recently has been described by some of us. The explanation for this almost counterintuitive paradox has yet to be determined, but a number of hypotheses were advanced, including hemodynamic factors producing aortic wall shear stress (WSS). The purpose of the present study was to determine if there was a relationship between AA and WSS, as determined by postmortem measurement of aortic wall diameters. METHODS: Circumferences of the aorta at the levels of the ascending, thoracic and abdominal aorta were measured in 274 consecutive autopsies over 2-year period of time. AA was assessed using a previously described grading scale as either mild or severe. Circumferences were mathematically converted to diameters and WSS was calculated using the Hagen-Poiseuille formula. Two different methods to estimate cardiac output were used, both based on literature methods, one of which was body mass index (BMI) dependent, and the other BMI independent. Univariate and multivariable analyses of the relationship between WSS, age, BMI, gender, race and severity of AA were performed. RESULTS: Of the 274 decedents, 140 had mild and 134 had moderate to severe AA. BMI <35 was associated with moderate to severe AA. WSS was inversely correlated with AA in all these segments of the aorta in each BMI subgroup with the exception of the ascending aorta for decedents with BMI ≤35 kg/m2. Contrary to what we had hypothesized, WSS was not a determinant of the obesity paradox. However, among all the variables analyzed, a history of hypertension, diabetes mellitus and age were significant factors for developing AA (relative risk [RR] 0.35, P = .039; RR 1.51, P = .0006, RR 1.19, P = .0001, respectively). CONCLUSIONS: Our data demonstrate that WSS was unexpectedly lower in decedents with moderate and severe AA as compared to those with mild AA. This observation, which requires further investigations, was seen in all BMI ranges and was confirmed by 2 methods to calculate WSS.