Proteomic analysis of the esophageal epithelium reveals key features of eosinophilic esophagitis pathophysiology.

BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic non-IgE-mediated allergic disease of the esophagus. An unbiased proteomics approach was performed to investigate pathophysiological changes in esophageal epithelium. Additionally, an RNAseq-based transcriptomic analysis in paired samples was also carried out. METHODS: Total proteins were purified from esophageal endoscopic biopsies in a cohort of adult EoE patients (n = 25) and healthy esophagus controls (n = 10). Differentially accumulated (DA) proteins in EoE patients compared to control tissues were characterized to identify altered biological processes and signaling pathways. Results were also compared with a quantitative proteome dataset of the human esophageal mucosa. Next, results were contrasted with those obtained after RNAseq analysis in paired samples. Finally, we matched up protein expression with two EoE-specific mRNA panels (EDP and Eso-EoE panel). RESULTS: A total of 1667 proteins were identified, of which 363 were DA in EoE. RNA sequencing in paired samples identified 1993 differentially expressed (DE) genes. Total RNA and protein levels positively correlated, especially in DE mRNA-proteins pairs. Pathway analysis of these proteins in EoE showed alterations in immune and inflammatory responses for the upregulated proteins, and in epithelial differentiation, cornification and keratinization in those downregulated. Interestingly, a set of DA proteins, including eosinophil-related and secreted proteins, were not detected at the mRNA level. Protein expression positively correlated with EDP and Eso-EoE, and corresponded with the most abundant proteins of the human esophageal proteome. CONCLUSIONS: We unraveled for the first time key proteomic features involved in EoE pathogenesis. An integrative analysis of transcriptomic and proteomic datasets provides a deeper insight than transcriptomic alone into understanding complex disease mechanisms.

Enigma portal: Undifferentiated thyroid malignant neoplasm in a patient with Hashimoto's thyroiditis.

Undifferentiated anaplastic thyroid tumours are uncommon and constitute a diagnostic challenge on fine needle aspiration. A case showing large, single neoplastic cells in a background of Hashimoto's disease is presented.

Sclerosing angiomatoid nodular transformation, a rare splenic tumor with increasing incidence.

SANT (sclerosing angiomatoid nodular transformation) tumor is a rare splenic tumor of unknown etiology and vascular lineage, first described in 2004. Most cases are asymptomatic, although cases of anemia or abdominal pain in association with growth have been described. Spontaneous ruptures have not been described. Radiologically it presents a radial pattern with centripetal filling in dynamic MRI, being a characteristic feature, but not pathognomonic. It may present hypermetabolism in PET-CT. Its incidence is increasing since its description as an independent clinical and histopathological entity, especially in the oncological patients follow-up. Due to its radiological resemblance to metastatic lesions and its growth despite being a vascular lesion, splenectomy is indicated following the principles of oncologic surgery until a definitive diagnosis is made. It presents a benign behavior, requiring neither treatment nor specific subsequent surveillance. Two diagnosed cases of SANT are presented, as well as a review of the clinical, radiological and histopathological characteristics of this little-known splenic lesion.

Chondroid Tumors: Review of Salient Imaging Features and Update on the WHO Classification.

Chondrogenic tumors are typically well recognized on radiographs, but differentiation between benign and malignant cartilaginous lesions can be difficult both for the radiologist and for the pathologist. Diagnosis is based on a combination of clinical, radiological and histological findings. While treatment of benign lesions does not require surgery, the only curative treatment for chondrosarcoma is resection. This article (1) emphasizes the update of the WHO classification and its diagnostic and clinical effects; (2) describes the imaging features of the various types of cartilaginous tumors, highlighting findings that can help differentiate benign from malignant lesions; (3) presents differential diagnoses; and (4) provides pathologic correlation. We attempt to offer valuable clues in the approach to this vast entity.

Cytologic Features of Lipogranulomatous Reaction in an Axillary Sentinel Lymph Node.

INTRODUCTION: Multinucleated giant cells (MGC) are a rare finding when evaluating axillary sentinel lymph nodes. Some are described as foreign body-type MGC accompanied by foamy macrophages. They have been rarely reported in nodes from patients in which a previous breast biopsy was performed. The tissue damage induced by biopsy results in secondary changes including fat necrosis and hemorrhage that can migrate to axillary nodes. In this report, we illustrate a lipogranulomatous reaction in cytologic samples obtained during a sentinel lymph node examination of a woman previously biopsied because of breast carcinoma. We have found no previous cytologic descriptions and consider it an interesting finding that should be known to avoid diagnostic misinterpretations. CASE: A 51-year-old woman underwent mastectomy of the right breast with a sentinel lymph node biopsy at our medical center. One month before, a control mammography revealed suspicious microcalcifications and a vacuum-assisted breast biopsy resulted in a diagnosis of high-grade intraductal carcinoma with comedonecrosis. Surgery with a sentinel lymph node biopsy was performed. The sentinel node was processed as an intraoperative consultation. Frozen sections and air-dried Diff-Quik stained samples were obtained. They showed abundant lymphocytes with MGC and tumoral cells. MGC showed ample cytoplasm with evident vacuoles of variable size. Occasional hemosiderin-laden macrophages were also present. The complete histologic analysis and immunohistochemical studies revealed no malignant cells. Histologic analysis showed, in subcapsular location, occasional MGC phagocyting lipid droplets. Hemosiderin-laden macrophages were a common finding. CONCLUSION: Lipogranulomas may appear at axillary sentinel lymph nodes because of fat necrosis induced by previous breast biopsy. The most important consideration is not confounding MGC with epithelial cell clusters. This can occur with not well-processed samples, especially if unmounted.

Cytologic Features of Ventricular Tumors of the Central Nervous System: A Review with Emphasis on Diff-Quik Stained Smears.

BACKGROUND: Neoplasms from the ventricular system share a common location but have highly variable histogenesis. Many are slowly growing tumors that behave in a benign fashion. They can be classified as primary and secondary tumors. The most common primary tumors are ependymomas, subependymomas, subependymal giant cell astrocytomas, central neurocytomas, choroid plexus tumors, meningiomas, germinomas, pineal parenchymal tumors, papillary tumors of the pineal region, chordoid gliomas, rosette-forming glioneuronal tumors of the fourth ventricle, and craniopharyngiomas. Pilocytic astrocytomas, medulloblastomas, and atypical teratoid/rhabdoid tumors often show secondary involvement of the ventricular system. SUMMARY: Advances in neurosurgery have facilitated access to the ventricular system increasing the number of cases in which such tumors can be biopsied. In this context, cytology has been proven to be an extremely useful diagnostic tool during intraoperative pathologic consultations. Many ventricular tumors are infrequent, and the cytologic information available is limited. In this review, we describe the cytologic features of the uncommon ventricular tumors and report on unusual findings of the more common ones. For the cytologic evaluation of brain tumors, many neuropathologists prefer formalin fixation and hematoxylin and eosin staining. In this review, we highlight the cytologic findings as seen with Diff-Quik, a very popular staining method among cytopathologists. In fact, when pathologists are unfamiliar with cytology, it is common to request the assistance of cytopathologists during the evaluation of intraoperative procedures. Key Message: Ventricular tumors of the central nervous system comprise a group of heterogeneous tumors with very different cytologic features. The cytomorphology of these tumors, including rare entities, is often very characteristic, allowing a precise recognition during intraoperative pathologic consultations. Diff-Quik is a valuable staining method that can be used alone or as a complement to hematoxylin and eosin staining. Diff-Quik allows for clear visualization of the overall architecture, cytoplasmic details, and extracellular material.

Increased number of pulmonary megakaryocytes in COVID-19 patients with diffuse alveolar damage: an autopsy study with clinical correlation and review of the literature.

Pulmonary megakaryocytes participate in the pathogenesis of lung damage, particularly in acute lung injury. Although megakaryocytes are not mentioned as a characteristic histologic finding associated to pulmonary injury, a few studies reveal that their number is increased in diffuse alveolar damage (DAD). In this autopsy study, we have observed a relevant number of pulmonary megakaryocytes in COVID-19 patients dying with acute lung injury (7.61 ± 5.59 megakaryocytes per 25 high-power fields vs. 1.14 ± 0.86 for the control group, p < 0.05). We analyzed samples of 18 patients, most of whom died after prolonged disease and use of mechanical ventilation. Most patients showed advanced DAD and abnormal coagulation parameters with high levels of fibrinogen, D-dimers, and variable thrombocytopenia. For comparison, pulmonary samples from a group of 14 non-COVID-19 patients dying with DAD were reviewed. They showed similar pulmonary histopathologic findings and an increase in the number of megakaryocytes (4 ± 4.17 vs. 1.14 ± 0.86 for the control group, p < 0.05). Megakaryocyte count in the COVID-19 group was greater but did not reach statistical significance (7.61 ± 5.59 vs. 4 ± 4.17, p = 0.063). Regardless of the cause, pulmonary megakaryocytes are increased in patients with DAD. Their high number seen in COVID-19 patients suggests a relation with the thrombotic events so often seen these patients. Since the lung is considered an active site of megakaryopoiesis, a prothrombotic status leading to platelet activation, aggregation and consumption may trigger a compensatory pulmonary response.

Tumor-Associated Granulomas Preceding a Diagnosis of Thoracic Sarcoidosis: A Retrospective, Single-Center Cohort Study.

There is a relationship between systemic sarcoidosis (SS) and malignancy. Sarcoidosis results from an exaggerated immune response in genetically susceptible individuals. In oncologic patients with sarcoidosis, tumoral antigens and antineoplastic treatment are considered potential triggering factors. The observation of a patient with granulomas in a parotid carcinoma who later developed SS led us to review the previous tumors of patients with SS. The aim of the study is to see whether granulomas were already present in the tumors that preceded sarcoidosis. We identified 196 sarcoidosis patients, 47 of whom had previously had a tumor. We were able to review 29 cases, 12 of which showed tumor-associated granulomas (TAGs) (41.4%). This ratio is much higher than that of the normal population (4.4-13.8). We analyzed five control patients without sarcoidosis for each tumor. In conclusion, we observed an increased number of TAGs in patients who later developed SS. This finding reinforces a pathogenic relationship between SS and neoplasia. The histology of tumors in patients with SS should be reviewed in an attempt to identify granulomas.

Oxyphil cells in primary hyperparathyroidism: a clinicopathological study.

BACKGROUND: The role of oxyphil cells (OxC) in primary hyperparathyroidism (PHPT) still remains controversial. Historically, they were believed to be involuted cells. However, they could play an important role in hormone secretion. The clinical behavior of OxC-rich adenomas and preoperative PHPT localization tests have been widely studied. The aim of this study is to analyze the implications of OxC in PHTP. METHODS: A retrospective cohort study of patients undergoing parathyroidectomy for PHPT was conducted. Additionally, we included normal glands removed in the context of PHPT or inadvertently during a thyroidectomy. All glands were reviewed independently by three researchers, performing a semi-quantitative analysis of the percentage of OxC. Groups with < 25% OxC and > 75% OxC were compared. RESULTS: In the period 2010-2017, 238 patients and 261 removed glands were included (8.8% OxCA > 75%). There were no differences in symptomatology and levels of preoperative calcium, parathormone, or 25-OH vitamin. Patients with OxCA > 75% had worse preoperative glomerular filtration rate (81.2 vs. 69.7 mL/min/1.73 m2; p = 0.043). They also had a trend towards larger size and weight (17 vs. 20 mm, p = 0.135 and 562 vs. 875 mg, p = 0.495), while ultrasound was found to have better accuracy (48.3% vs. 73.7%; p = 0.035). There were no normal glands with a content of OxC > 75%. CONCLUSIONS: Our study suggests that phosphocalcic metabolism is not influenced by the presence of a high content of OxC in the parathyroid glands. A high content of OxC seems to be exclusive to pathologic glands and could be related to the deterioration of renal function in patients with PHPT.

Kikuchi-Fujimoto Disease-Like Inflammatory Reaction in a Silicone Breast Implant Seroma.

INTRODUCTION: Kikuchi-Fujimoto disease (KFD) may have an autoimmune etiology and some cases have been associated with silicone breast implants. Cytomorphologic features of the disease have been well characterized by fine-needle aspiration of lymph nodes. They are so specific as to permit a precise cytologic diagnosis. Cytologic features have not been reported in fluid specimens. CASE: A 33-year-old female presented with a unilateral periprosthetic silicone breast seroma. The fluid was drained, and cytological analysis revealed numerous lymphocytes with no neutrophils, karyorrhectic nuclear debris, and peculiar histiocytes with eccentrically located nuclei showing a crescentic shape. Many of those histiocytes showed intracellular apoptotic debris. CONCLUSION: A Kikuchi disease-like inflammatory reaction is possible not only in axillary and cervical lymph nodes of patients with silicone breast implants but also in breast seromas. There is still not enough evidence to establish if there is an association between KFD and breast implants. A detailed cytologic examination of periprosthetic silicone breast seromas may help answer this question. In any case, pathologists must be aware of this possibility. Cytologic features are characteristic enough to permit differentiation from breast implant-associated anaplastic large-cell lymphoma.

Mesothelial-to-Mesenchymal Transition Contributes to the Generation of Carcinoma-Associated Fibroblasts in Locally Advanced Primary Colorectal Carcinomas.

During peritoneal metastasis, cancer cells spread from abdominal solid tumors, disseminate through the peritoneal fluid and attach to and invade through mesothelial cells (MCs) that line the peritoneum. Intestinal adenocarcinomas originating in the mucosa infiltrate the submucosa, muscle layer, and serosa in order to finally colonize the peritoneal cavity. However, the mechanism by which metastatic cells leave the primary tumor and reach the peritoneal cavity has not been previously described. Hence, we investigate whether MCs lining visceral peritoneum, through a mesothelial-to-mesenchymal transition (MMT), are a source of carcinoma-associated fibroblasts (CAFs), which could contribute to cancer progression toward the peritoneal cavity. CAFs detected in biopsies from patients with superficially invasive colorectal cancer differed from locally advanced tumors. An aberrant accumulation of myofibroblasts expressing mesothelial markers was found in the stroma of deeply infiltrative tumors located in the neighborhood of a frequently activated mesothelium. We suggest that MMT is a key event in the early stages of peritoneal dissemination.

Fine needle aspiration cytology of polymorphous adenocarcinoma of the salivary glands: A report of 11 patients and review of the literature.

BACKGROUND: Polymorphous adenocarcinoma (PAC) is a rare malignant tumor of the minor salivary glands. It has an infiltrative growth, variable architectural patterns, neurotropism and cellular monomorphism. Approximately 75% of the cases show a specific mutation in the protein kinase D1 (PRKD1) gene. Reflecting the rarity of the tumor and intraoral location, the cytologic experience is limited with few reported series. In this study we analyze our cytologic experience to determine if a preoperative diagnosis is possible. METHODS: A retrospective study of 11 patients with PAC in which a cytologic study was available. A review of the literature was also performed. RESULTS: Our study shows that PAC has relatively constant cytological features. The analysis of the cytological literature although it shows some heterogeneity, also reveals repetitive cytological findings. Smears are cellular with irregular groups some showing pseudopapillary branching morphology. Monolayered clusters and small acinar structures are also present. Most cases have small metachromatic globules embedded within the groups determining a cylindromatous pattern. Tumoral cells are small and uniform with scarce to moderate cytoplasm. Nuclei are round and oval with occasional grooves and small nucleoli. CONCLUSION: PAC has characteristic cytological features that together with its location in minor salivary gland must make us consider it preoperatively. It may resemble basal cell adenoma and epithelial-rich pleomorphic adenoma so we should be cautious in the final diagnosis. Whenever possible, the characteristic cytomorphology of PCA should make us evaluate the mutational status of PRKD1 gene since it may permit a more accurate diagnosis.

FNA cytology of postoperative pseudotumoral lesions induced by oxidized cellulose hemostatic agents.

BACKGROUND: The use of topically applied hemostatic substances during surgery has become a common practice. In some cases, the material is not absorbed or induces a granulomatous reaction resulting in a pseudotumoral lesion. With imaging studies, it is not possible to differentiate this from a tumor recurrence or abscess. This study describes the authors' cytologic experience with a large series of pseudotumoral lesions induced by oxidized cellulose, one of the most commonly used hemostatic agents. Almost no cytologic descriptions are available in the medical literature. METHODS: Sixteen patients were evaluated, and the most common sites of fine-needle aspiration (FNA) were the mediastinum and thyroid surgical bed. Other locations were the axilla, neck, vulva, liver, and retroperitoneum. All these lesions appeared after surgical procedures in which oxidized cellulose was used as a topical hemostatic agent. The interval time between surgery and FNA varied from 4 to 46 months with a mean of 15 months. RESULTS: Cytology samples showed very similar findings. In all cases, foreign-body material with a variable granulomatous reaction was present. Oxidized cellulose was seen as laminated inorganic fragments and most often showed an elongated, quadrangular appearance. Amorphous, ill-defined fragments as well as a dense proteinaceous background with phagocytic cells were also present. CONCLUSIONS: The current study demonstrates that FNA cytology is a very useful method for the detection of pseudotumoral lesions induced by hemostatic agents. Pathologists must be familiarized with this finding because cytology permits easy differentiation from tumor recurrence.

Cytological features of breast peri-implant papillary synovial metaplasia.

Synovial metaplasia is a peculiar form of metaplasia seen in the inner lining of the fibrous capsule that surrounds breast implants. Since the description of breast-implant associated anaplastic large cell lymphoma it is increasingly common to receive periprosthetic breast fluid collections for pathologic analysis. We describe a case of breast-implant papillary synovial metaplasia that showed remarkable cytologic findings. A review of the medical literature revealed one previous cytologic description. The patient, A 53-year-old woman underwent surgery because of capsular contracture of textured, silicone breast implants. During surgery, 5 ml of peri-implant fluid collection fluid and the fibrotic capsules were submitted for pathologic analysis. The fluid was dense and smears showed abundant mucoid material that distributed on the background as a thick layer showing a wrinkled, "plastic food wrap" pattern. Numerous ball-like, three-dimensional spherical structures with a very well-defined contour were present. At low power magnification they created a worrisome cytologic image. Spherules consisted of cells embedded in a fibrous extracellular matrix. Cells showed round to oval nuclei with no pleomorphism. In the outer part of the spherules oval to spindle nuclei, parallel to the surface were evident. Histology of the resected capsules revealed remarkable papillary synovial metaplasia in addition to fibrosis and silicone deposition. In our opinion the spherules observed on cytology correspond to detached papillary fragments of synovial metaplasia. Their cytologic features are characteristic enough to permit a specific recognition avoiding misinterpretations. Pathologists must consider this diagnostic possibility whenever evaluating breast peri-implant fluid accumulations.

Cytologic Features of Malignant Melanoma with Osteoclast-Like Giant Cells.

BACKGROUND: Malignant melanoma showing numerous osteoclast-like giant cells (OGCs) is an uncommon morphologic phenomenon, rarely mentioned in the cytologic literature. The few reported cases seem to have an aggressive clinical behavior. Although most findings support monocyte/macrophage differentiation, the exact nature of OGCs is not clear. CASE: A 57-year-old woman presented with an inguinal lymphadenopathy. Sixteen years before, cutaneous malignant melanoma of the lower limb had been excised. Needle aspiration revealed abundant neoplastic single cells as well as numerous multinucleated OGCs. Occasional neoplastic giant cells were also present. Nuclei of OGCs were monomorphic with oval morphology and were smaller than those of melanoma cells. The immunophenotype of OGCs (S100-, HMB45-, Melan-A-, SOX10-, Ki67-, CD163-, BRAF-, CD68+, MiTF+, p16+) was the expected for reactive OGCs of monocyte/macrophage origin. The tumor has shown an aggressive behavior with further metastases to the axillary lymph nodes and oral cavity. CONCLUSION: Numerous OGCs are a rare and relevant finding in malignant melanoma. Their presence should not induce confusion with other tumors rich in osteoclastic cells. Since a relevant number of OGCs in melanoma may mean a more aggressive behavior, and patients may benefit from specific treatments, their presence should be mentioned in the pathologic report.

Fine needle aspiration cytology of the normal kidney: A cyto-histological and immunocytochemical correlation study.

BACKGROUND: Differentiation between normal renal cellular structures and renal tumors can be a diagnostic challenge during fine needle aspiration. It is of particular relevance during percutaneous thermal ablation because of the small size of tumors and when performing rapid on-site evaluation. METHODS: A cyto-histological correlation study assisted by immunocytochemistry was performed. The study was based on 10 nephrectomy specimens. For the identification of proximal tubular cells we used CD10 and α-methylacyl coenzyme A racemase (AMACR). PAX8 and GATA3 were used for the recognition of distal and collecting duct cells. For a precise correlation representative cytologic groups were photographed before and after immunocytochemistry. RESULTS: All cases showed: (a) glomeruli; (b) presence of at least 2 different epithelial cell populations that distribute separately, one representing the proximal tubule and the other more distal segments; and (c) existence of isolated, laminar basement fragments and slender, intact tubular structures. Proximal tubular cells were large with granular cytoplasm, indistinct cell borders, moderate anisonucleosis, and variable presence of pigment. Their immunophenotype was CD10+, AMACR+, PAX8-, and GATA3-. In all cases, cellular aggregates different of nonproximal tubular cells were present. They were smaller than proximal tubular cells with less cytoplasm, better-defined cell borders and uniform nuclei. Their immunophenotype was CD10-, AMACR-, PAX8+, and GATA3+ CONCLUSION: Aspirates from the normal kidney show characteristic features that permit a specific recognition. Different segments of the tubular system can be specifically recognized avoiding confusion with renal tumors. In difficult cases immunocytochemistry is a very helpful aid.