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GI Utilizing DOG1 Antibody to Diagnose Gastrointestinal Stromal Tumors
Abstracts
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with surgical pathology biopsy and/or resection diagnoses when available (95%). Conclusion: FNA is a valuable diagnostic technique for differentiation of primary adrenal gland lesions versus metastatic malignancy.
Figure 2
Oncocytic pheochromocytoma
reviewed. The staining intensity of AS were observed and recorded as pale (P), non-pale (NP) and mixed (M), when both P and NP were present simultaneously. Results: 29 cases included FNAs from varying anatomic sites, including breast(13), neck(8), axilla(3), parotid(2), chest wall(1) and cheek(1) were found. AS staining was observed to be P 21(72%), M 8(28%) and NP 0(0%). 7(23%) cases had surgical follow-up. 6 of 8 M cases demonstrated acute inflammation, in addition to AS. Conclusion: AS are a significant component of ECs and have been a widely recognized finding in FNAs. While this may be so, the literature has failed to recognize explicitly the delicate and pale-staining nature of AS in ECs. The staining may be so faint in PAP slides that in some instances the cells may not even be recognized, leading to incorrect categorization of the case as inadequate. The inflammatory component in M cases may represent either inflamed cyst contents or recent rupture and is the most likely explanation for the M pattern observed. Heightened awareness of the delicate and relatively pale-staining characteristics of AS seen in FNAs of ECs will hopefully lead to more consistent recognition of this lesion.
GI 26 GI Utilizing DOG1 Antibody to Diagnose Gastrointestinal Stromal Tumors
Figure 3
Figure 4
Metastatic clear cell renal carcinoma
Metastatic (esophageal) squamous cell CA
25 Pale-Staining Anucleate Squames in Epidermoid Cyst Contents Obtained by Fine Needle Aspiration Charvi Patel, MD, PhD, Jessica Niakan, MD, Shabnam Jaffer, MD, Arnold Szporn, MD The Icahn School of Medicine at Mount Sinai, New York, New York Introduction: Anucleate squames (AS) are a component of epidermoid cyst (EC) contents in obtained by fine needle aspiration (FNA) of superficial lesions. AS in ECs are often delicate and relatively palestaining, an observation, to our knowledge, not previously reported in the literature. In our experience, both cytotechnologists and cytopathologists have, on occasion, failed to detect the presence of AS in FNA specimens, leading them to incorrectly categorize the cases as inadequate. Material and Methods: Hospital files were searched for cases of FNAs of ECs between 01/01/10 and 04/10/15. Papanicolaou-stained (PAP) smears and Thin-PrepsÒ (TP), Diff-Quik-stained (DQ) smears and hematoxylin-eosin (H&E)-stained cell blocks were retrieved and
Alanna Chiu, BS, CT(ASCP), Margaret Tavares, BS, SCT(ASCP), Desiree Palafox, BS, SCT(ASCP), Camilla J. Cobb, MD Loma Linda University, Loma Linda, California Introduction: Gastrointestinal stromal tumor (GIST) is characterized by activating mutations in receptor tyrosine kinases, CD117 and PDGFRa. All GISTs are potentially malignant making early diagnosis crucial. Distinguishing GISTs from other intra-abdominal spindle cell tumors is challenging and relies on immunohistochemistry (IHC) targeting CD117 and CD34; however, up to 15% of GISTs show no expression including wild-type GISTs. Regardless, these tumors are sensitive to the same therapy as those with positive expression. A new protein, DOG1, demonstrated high expression in GISTs, including CD117 negative and wild-type GISTs and is uncommonly expressed in other soft tissue tumors. DOG1 showed a higher sensitivity and specificity in comparison to CD117. This study investigated the effectiveness of DOG1 to detect confirmed GIST cases in comparison to differential diagnostic lesions. Materials and Methods: Study included archived formalin fixed, paraffin embedded tissue biopsies/cell block preparations of nineteen GISTs, five leiomyosarcomas, five schwannomas, and one spindle cell proliferation. Manual IHC staining was performed using ImmunoCruzTM rabbit ABC Staining System with pre-diluted rabbit monoclonal, SP31, DOG1 antibody. Antigen retrieval was performed by heating slides with 10mM citrate buffer in boiling water for 10 minutes. Primary antibody incubation time was 60 minutes. Positive control was one confirmed GIST case. Negative control was same specimen with absence of primary antibody. Cytoplasmic and/or membranous brown pigment staining indicated positivity. A pathologist graded staining intensity using a scale of 0 as negative and 1-4 as positive. Sensitivity and specificity were calculated by standard method. Results: 100% (18/18) GIST cases stained positive for DOG1. 90% (8/9) of diagnostic differentials lacked expression (Table 1). Sensitivity and specificity are 100% and 90%, respectively. Conclusion: DOG1 appears to be a sensitive and specific marker with potential for differentiating GIST from other abdominal spindle cell tumors. Utilizing DOG1 may improve diagnostic accuracy with CD117 negative and wild-type GISTs.
S18
Abstracts cytologic diagnosis reviewed each case for distinctive cytomorphologic features. Results: Twenty-nine cases were included. Demographic data is represented in Table 1. Seven were epithelioid, three were mixed, and nineteen were spindle cell GISTs. Five were malignant GISTs (three epithelioid, two spindle cell). Spindle cell GISTs were more likely to have palisading more often than epithelioid GISTs, while epithelioid GISTs more often had single cells/dyshesion (Table 2). Epithelioid cells and rhabdoid cells were only found in epithelioid GISTs. Spindle cells were present in all types of GISTs and could not be used to delineate spindle cell GISTs from other types of GISTs. Binucleation and nucleoli were more often seen in epithelioid GISTs. No distinguishing morphologic differences between malignant and non-malignant GISTs were found. Conclusion: Few morphologic features can distinguish types of GIST on FNA. Epithelioid and/or rhabdoid cells, binucleation, and prominent nucleoli are cytomorphologic features that can be useful to identify epithelioid GISTs. Palisading more often occurs in spindle cell GISTs, while single cells/dyshesion is more often seen in epithelioid GISTs. No morphologic distinctions between malignant and non-malignant GISTs were found in our study.
Table 1
Demographic data for all GISTs (nZ29)
Table 2
Comparison of cytomorphologic features
Table 1
27 Morphologic Findings in Fine Needle Aspiration Cytology of Gastrointestinal Stromal Tumors Amber Smith, MD, Jordan Reynolds, MD, Deborah Chute, MD The Cleveland Clinic, Cleveland, Ohio Introduction: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal tract. Information regarding the cytomorphology of different types of GISTs available in the cytology literature is limited. Our study analyzed the cytomorphologic features of epithelioid, spindle cell, mixed, and malignant GISTs sampled by fine needle aspiration (FNA). Materials and Methods: The medical record was retrospectively reviewed for all GISTs resected or biopsied from 1/1/2000-12/9/2014. Cases with a prior FNA with well visualized material were included. Malignancy was defined as local recurrence and/or metastasis. Demographic data was collected. Two cytopathologists blinded to the original
S17
with surgical pathology biopsy and/or resection diagnoses when available (95%). Conclusion: FNA is a valuable diagnostic technique for differentiation of primary adrenal gland lesions versus metastatic malignancy.
Figure 2
Oncocytic pheochromocytoma
reviewed. The staining intensity of AS were observed and recorded as pale (P), non-pale (NP) and mixed (M), when both P and NP were present simultaneously. Results: 29 cases included FNAs from varying anatomic sites, including breast(13), neck(8), axilla(3), parotid(2), chest wall(1) and cheek(1) were found. AS staining was observed to be P 21(72%), M 8(28%) and NP 0(0%). 7(23%) cases had surgical follow-up. 6 of 8 M cases demonstrated acute inflammation, in addition to AS. Conclusion: AS are a significant component of ECs and have been a widely recognized finding in FNAs. While this may be so, the literature has failed to recognize explicitly the delicate and pale-staining nature of AS in ECs. The staining may be so faint in PAP slides that in some instances the cells may not even be recognized, leading to incorrect categorization of the case as inadequate. The inflammatory component in M cases may represent either inflamed cyst contents or recent rupture and is the most likely explanation for the M pattern observed. Heightened awareness of the delicate and relatively pale-staining characteristics of AS seen in FNAs of ECs will hopefully lead to more consistent recognition of this lesion.
GI 26 GI Utilizing DOG1 Antibody to Diagnose Gastrointestinal Stromal Tumors
Figure 3
Figure 4
Metastatic clear cell renal carcinoma
Metastatic (esophageal) squamous cell CA
25 Pale-Staining Anucleate Squames in Epidermoid Cyst Contents Obtained by Fine Needle Aspiration Charvi Patel, MD, PhD, Jessica Niakan, MD, Shabnam Jaffer, MD, Arnold Szporn, MD The Icahn School of Medicine at Mount Sinai, New York, New York Introduction: Anucleate squames (AS) are a component of epidermoid cyst (EC) contents in obtained by fine needle aspiration (FNA) of superficial lesions. AS in ECs are often delicate and relatively palestaining, an observation, to our knowledge, not previously reported in the literature. In our experience, both cytotechnologists and cytopathologists have, on occasion, failed to detect the presence of AS in FNA specimens, leading them to incorrectly categorize the cases as inadequate. Material and Methods: Hospital files were searched for cases of FNAs of ECs between 01/01/10 and 04/10/15. Papanicolaou-stained (PAP) smears and Thin-PrepsÒ (TP), Diff-Quik-stained (DQ) smears and hematoxylin-eosin (H&E)-stained cell blocks were retrieved and
Alanna Chiu, BS, CT(ASCP), Margaret Tavares, BS, SCT(ASCP), Desiree Palafox, BS, SCT(ASCP), Camilla J. Cobb, MD Loma Linda University, Loma Linda, California Introduction: Gastrointestinal stromal tumor (GIST) is characterized by activating mutations in receptor tyrosine kinases, CD117 and PDGFRa. All GISTs are potentially malignant making early diagnosis crucial. Distinguishing GISTs from other intra-abdominal spindle cell tumors is challenging and relies on immunohistochemistry (IHC) targeting CD117 and CD34; however, up to 15% of GISTs show no expression including wild-type GISTs. Regardless, these tumors are sensitive to the same therapy as those with positive expression. A new protein, DOG1, demonstrated high expression in GISTs, including CD117 negative and wild-type GISTs and is uncommonly expressed in other soft tissue tumors. DOG1 showed a higher sensitivity and specificity in comparison to CD117. This study investigated the effectiveness of DOG1 to detect confirmed GIST cases in comparison to differential diagnostic lesions. Materials and Methods: Study included archived formalin fixed, paraffin embedded tissue biopsies/cell block preparations of nineteen GISTs, five leiomyosarcomas, five schwannomas, and one spindle cell proliferation. Manual IHC staining was performed using ImmunoCruzTM rabbit ABC Staining System with pre-diluted rabbit monoclonal, SP31, DOG1 antibody. Antigen retrieval was performed by heating slides with 10mM citrate buffer in boiling water for 10 minutes. Primary antibody incubation time was 60 minutes. Positive control was one confirmed GIST case. Negative control was same specimen with absence of primary antibody. Cytoplasmic and/or membranous brown pigment staining indicated positivity. A pathologist graded staining intensity using a scale of 0 as negative and 1-4 as positive. Sensitivity and specificity were calculated by standard method. Results: 100% (18/18) GIST cases stained positive for DOG1. 90% (8/9) of diagnostic differentials lacked expression (Table 1). Sensitivity and specificity are 100% and 90%, respectively. Conclusion: DOG1 appears to be a sensitive and specific marker with potential for differentiating GIST from other abdominal spindle cell tumors. Utilizing DOG1 may improve diagnostic accuracy with CD117 negative and wild-type GISTs.
S18
Abstracts cytologic diagnosis reviewed each case for distinctive cytomorphologic features. Results: Twenty-nine cases were included. Demographic data is represented in Table 1. Seven were epithelioid, three were mixed, and nineteen were spindle cell GISTs. Five were malignant GISTs (three epithelioid, two spindle cell). Spindle cell GISTs were more likely to have palisading more often than epithelioid GISTs, while epithelioid GISTs more often had single cells/dyshesion (Table 2). Epithelioid cells and rhabdoid cells were only found in epithelioid GISTs. Spindle cells were present in all types of GISTs and could not be used to delineate spindle cell GISTs from other types of GISTs. Binucleation and nucleoli were more often seen in epithelioid GISTs. No distinguishing morphologic differences between malignant and non-malignant GISTs were found. Conclusion: Few morphologic features can distinguish types of GIST on FNA. Epithelioid and/or rhabdoid cells, binucleation, and prominent nucleoli are cytomorphologic features that can be useful to identify epithelioid GISTs. Palisading more often occurs in spindle cell GISTs, while single cells/dyshesion is more often seen in epithelioid GISTs. No morphologic distinctions between malignant and non-malignant GISTs were found in our study.
Table 1
Demographic data for all GISTs (nZ29)
Table 2
Comparison of cytomorphologic features
Table 1
27 Morphologic Findings in Fine Needle Aspiration Cytology of Gastrointestinal Stromal Tumors Amber Smith, MD, Jordan Reynolds, MD, Deborah Chute, MD The Cleveland Clinic, Cleveland, Ohio Introduction: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal tract. Information regarding the cytomorphology of different types of GISTs available in the cytology literature is limited. Our study analyzed the cytomorphologic features of epithelioid, spindle cell, mixed, and malignant GISTs sampled by fine needle aspiration (FNA). Materials and Methods: The medical record was retrospectively reviewed for all GISTs resected or biopsied from 1/1/2000-12/9/2014. Cases with a prior FNA with well visualized material were included. Malignancy was defined as local recurrence and/or metastasis. Demographic data was collected. Two cytopathologists blinded to the original