Enterprise Interest Nothing to declare

Enterprise Interest Nothing to declare

Iulia Bârsan, MD, Lien Hoang, MD, Cristina Terinte, MD, Anna Pesci, MD, Sarit Aviel-Ronen, MD, Takako Kiyokawa, MD, Isabel Alvarado- Cabrero, MD, Esther Oliva, MD, Kay J. Park, MD, Robert A. Soslow, MD, Simona Stolnicu, MD The Differential Diagnosis of Cervical Adenosquamous Carcinoma (CAC) and Related Entities

Is an uncommon histologic subtype classified by the latest World Health Organization (WHO) Classification of Tumors of Female Reproductive Organs as a separate category from both squamous and cervical glandular malignant tumors WHO definition: ``an epithelial malignant tumor comprising both adenocarcinoma and squamous cell carcinoma`` with ``sufficient differentiation of the adenocarcinomatous component to include histologically recognizable glands`` and also squamous differentiation (keratinization and squamous bridges) 1 Armed Forces Institute (AFIP) : ``both of the component poorly differentiated``; differential diagnosis: poorly differentiated adenocarcinoma of the endometrium, cervical adenocarcinoma with H-SIL component or squamous carcinoma (collision tumor) 2 Introduction Cervical adenosquamous carcinoma (CAC) 1:WHO Classification of Tumours of Female Reproductive Organs, 2014; 2:Armed Forces Institute of Pathology,2010

WHO Definition: ``a poorly differentiated variant of adenosquamous carcinoma``1 Introduction Morphologic characteristics: cells with sharp cytoplasm, ``ground glass`` appearing eosinophilic cytoplasm, prominent eosinophil infiltrate Usually a preinvasive component is not seen 1 Significant interobserver variability 1 Glassy cell carcinoma (GCC) 1.WHO Classification of Tumours of Female Reproductive Organs, 2014;

Introduction Both definitions (CAC and GCC) are ambiguous, lacking precise morphologic criteria and cut offs for each component Similarly ambiguous definition in cervical adenocarcinoma, until recently - International Endocervical Adenocarcinoma Criteria and Classification (IECC) based on morphological features linked to etiology (Stolnicu, 2017) Although the WHO 2014 criteria require the presence of unequivocal glandular and squamous differentiation, CAC in practice represents a diverse spectrum of lesions, some of which do not exhibit unequivocal squamous differentiation.

Objective 1 2 3 To establish precise morphological criteria for diagnosing CACs To establish immunohistochemical markers that can be useful in the diagnosis To establish other lesions that can mimic CACs according to the latest literature

MATERIALS AND METHODS

MATERIALS AND METHODS Morphologic criteria used to diagnose the cases Adenosquamous carcinoma: unequivocal malignant glandular and squamous differentiation, at least 10% each component Glassy cell carcinoma: sharp cytoplasmic margins, ground glass eosinophilic cytoplasm, large round or ovoid nuclei with prominent nucleoli Usual type adenocarcinoma with benign squamous metaplasia: pseudostratification, hyperchromatic nuclei, apical mitoses and apoptosis with extensive component of benign appearing squamous mucosa (IECC) Mucinous NOS: cytoplasmic mucin in more than 50% of cells (IECC) Invasive SMILE: nests of columnar/cuboidal cells, nuclear peripheral palisading; variable amount of intracytoplasmic mucin throughout entire thickness

MATERIALS AND METHODS Immunohistochemistry (TMA) p16 p63 p40 PAX 8 SATB 2

RESULTS Morphologic Examination Immunohistochemical profile (n=26) Immunohistochemical profile (n=2) Immunohistochemical profile (n=17)

RESULTS p16 Cases Positive Negative CACs (n=26) 73% (n=19) 27% (n=5) GCCs (n=2) 50% (n=1) 50% (n=1) Mimic lesions (n=17) 76% (n=13) 14% (n=4) p16 was interpreted as positive if diffuse, block-like staining was found in all cores; whereas no staining, or patchy staining, was interpreted as negative.

RESULTS HPV Positive Negative CACs (n=22) 87% (n=19) 13% (n=3) GCCs (n=2) 100% (n=2) 0 Mimic lesions (n=13) 100% (n=13) 0 HPV in-situ hybridization with a chromogen using the Advanced Cell Diagnostics The RNAscope Probe HPV HR18 if any nuclear or cytoplasmic ``dots`` were seen, it was score as positive

RESULTS p63 Cases Positive Negative CACs (n=25) 60% (n=15) 40% (n=10) GCCs (n=2) 0 100% (n=2) Mimic lesions (n=16) 6% (n=1) 94% (15) p63 was interpreted as positive if moderate to strong nuclear stain was seen, in over 10% of tumor cells

RESULTS p40 Cases Positive Negative CACs (n=22) 67% (n=14) 33% (n=8) GCCs (n=2) 50% (n=1) 50% (n=1) Mimic lesions (n=13) 31% (n=4) 69% (n=9) p40 was interpretated as positive if nuclear stain was observed in over 5% of tumor cells

RESULTS Other IHC PAX 8 % SATB 2 HNF 1β POS NEG POS NEG POS NEG CACs 47% 53% 0% 100% 32% 68% GCCs 0 100% 0% 100% 50% 50%

RESULTS ismile N=8 p16 % HPV % p63 % p40 % POS NEG POS NEG POS NEG POS NEG ismile 50% 50% 100% - 14% 86% 28% 72% RESULTS N=4 p16 % HPV % p63 % p40 % UEA with Squamous Metaplasia UEA with benign squamous metaplasia POS NEG POS NEG POS NEG POS NEG 100% - 100% - - 100% 25% 75%

Discussion CAC and GCC morphological diagnosis

Discussion CAC and GCC morphological diagnosis When precise cut offs and morphologic characteristics are used, fewer cases are diagnosed as CACs and GCCs CAC mimickers are a diverse spectrum of lesions that comprise tumors with intracytoplasmic mucinous features, squamous metaplasia, or poorly differentiated histology

Discussion CACs differential diagnosis should include: 1 2 3 4 5 ismile Usual type adenocarcinoma with ismile component Usual type adenocarcinoma with benign squamous metaplasia Mucinous NOS adenocarcinoma with ismile component Poorly differentiated adenocarcinoma

Discussion Immunohistochemistry CACs and GCCs are p16 and HPV positive, confirming viral etiology; HPV results are comparable with data from literature: -CAC- 87% compared to 86% 1 and 88% 2 -GCC- 100% compared to 66% 3 p63 has a higher positivity in CACs compared to ismile (that are typically negative) 4 and usual adenocarcinoma with benign squamous metaplasia p40 is a more specific marker for squamous differentiation than p63 5 also has a higher positivity in CACs compared to ismile and usual adenocarcinoma with benign squamous metaplasia 1. Ueda, 2008; 2. Molijin, 2016; 3. Kato,2002; 4 Lastra,2016; 5. Quosho,2016;

Discussion Immunohistochemistry Pax 8 positivity is reported in up to 29% of CACs, our cohort has a higher positivity 1 HNF1 β is known as a specific and sensitive marker for tumors with clear cell features, in our study 32% of CACs were positive and 50% of GCCs SATB 2 is a specific and sensitive marker for diagnosing colorectal carcinomas 3 from tumors of other origin, 100% negativity in CACs and GCCs was expected 1.Wong,2017; 2.Tsuchiya,2003; Dragomir, 2014

Deficiencies p16 Deficiencies for CACs p16 negativity (27%) and GCCs (50%) -TMA does not represent the entire tumor -Blocks from different laboratories, may have different protocols for tissue process -Old blocks (>5 years)

Conclusions 1 2 3 4 ismile (as a pure lesion or as a component in other subtypes) is one of the major differential diagnosis of CACs p63 and p40 are useful markers for CACs differential diagnosis HPV ISH (mrna) is a more robust maker than p16 Outcome analysis between CACs, GCC and IECC HPVA tumors are ongoing