Chronic Allergic-like Inflammation in the Tumor Stroma of Human Gastric Carcinomas: An Ultrastructural Study

Adenosquamous carcinoma of the uterine cervix displaying tumor-associated tissue eosinophilia

Background:

Tumor-associated tissue eosinophilia is defined as an inflammatory response with the marked infiltration of eosinophils within tumor tissues. Tumor-associated tissue eosinophilia has been reported in various organs; however, no studies have examined the detailed cytopathological findings of tumor-associated tissue eosinophilia.

Case Presentation:

A 49-year-old woman presented with lower abdominal and back pain that had started 1 month earlier. A cervical biopsy revealed a diagnosis of non-keratinizing squamous cell carcinoma. A mildly increased number of eosinophils was observed in both cervical cytology and a biopsy. On pelvic computed tomography, a tumor mass measuring up to 5.5 cm in the largest diameter was seen in the uterine cervix. After 1 month, endometrial cytology was performed, and non-keratinizing squamous cell carcinoma together with normal endometrial glands was obtained in a background of marked eosinophil numbers. Tumor cells in an irregular-shaped solid nest had variable-sized hyperchromatic nuclei and light-green-stained cytoplasm. The number of eosinophils was obviously increased. Considering the possibility of tumor-associated tissue eosinophilia, we evaluated a peripheral blood sample and confirmed an increased number of eosinophils. Radical hysterectomy was performed, and the final pathological diagnosis was adenosquamous carcinoma. Although the number of eosinophils decreased after surgery, it increased again at the time of recurrence 1 year later. Chemo-irradiation was performed, but the patient died 1 year and 8 months after the operation.

Conclusion:

Cytopathologists should consider the presence of tumor-associated tissue eosinophilia by focusing on not only tumor cells but also the markedly eosinophilic background. The eosinophil count might be a useful marker of the disease activity.

Hypoxia causes IL-8 secretion, Charcot Leyden crystal formation, and suppression of corticosteroid-induced apoptosis in human eosinophils

BACKGROUND

Inflamed environments are typically hypercellular, rich in pro-inflammatory cytokines, and profoundly hypoxic. While the effects of hypoxia on neutrophil longevity and function have been widely studied, little is known about the consequences of this stimulus on eosinophils.

OBJECTIVE

We sought to investigate the effects of hypoxia on several key aspects of eosinophil biology, namely secretion, survival, and their sensitivity to glucocorticosteroids (GCS), agents that normally induce eosinophil apoptosis.

METHODS

Eosinophils derived from patients with asthma/atopy or healthy controls were incubated under normoxia and hypoxia, with or without glucocorticoids. Activation was measured by flow cytometry, ELISA of cultured supernatants, and F-actin staining; apoptosis and efferocytosis by morphology and flow cytometry; and GCS efficacy by apoptosis assays and qPCR.

RESULTS

Hypoxic incubation (3 kPa) caused (i) stabilization of HIF-2α and up-regulation of hypoxia-regulated genes including BNIP3 (BCL2/adenovirus E1B 19-kDa protein-interacting protein 3) and GLUT1 (glucose transporter 1); (ii) secretion of pre-formed IL-8, and Charcot Leyden crystal (CLC) formation, which was most evident in eosinophils derived from atopic and asthmatic donors; (iii) enhanced F-actin formation; (iv) marked prolongation of eosinophil lifespan (via a NF-κB and Class I PI3-kinase-dependent mechanism); and (v) complete abrogation of the normal pro-apoptotic effect of dexamethasone and fluticasone furoate. This latter effect was evident despite preservation of GCS-mediated gene transactivation under hypoxia.

CONCLUSION AND CLINICAL RELEVANCE

These data indicate that hypoxia promotes an eosinophil pro-inflammatory phenotype by enhancing eosinophil secretory function, delaying constitutive apoptosis, and importantly, antagonizing the normal pro-apoptotic effect of GCS. As eosinophils typically accumulate at sites that are relatively hypoxic, particularly during periods of inflammation, these findings may have important implications to understanding the behaviour of these cells in vivo.

Eosinophil-Specific Granules in Tumor Cell Cytoplasm: Unusual Ultrastructural Findings in a Case of Diffuse-Type Gastric Carcinoma

A case of desmoplastic variant of diffuse-type gastric carcinoma in a 72-year-old woman is reported. Microscopic findings included poorly cohesive tumor cells, resembling mononuclear inflammatory cells, prominent diffuse desmoplasia, and tumor-associated tissue eosinophilia. Electron microscopy confirmed the undifferentiated phenotype of tumor cells and disclosed activated eosinophils in the tumor stroma. Eosinophil-specific granules were found either free in the tumor stroma or within the cytoplasm of some tumor cells. Electron microscopy provided also circumstantial evidence of phagocytosis of apoptotic eosinophils by tumor cells. Extracellular, membrane-bound, eosinophil-specific granules have been long recognized in tissues associated with eosinophilia, including allergic diseases, inflammatory responses to helminths, and in stroma of some neoplasms. Our ultrastructural study now extends these findings and provides additional morphological evidence of eosinophil-specific granules within the cytoplasm of gastric carcinoma cells.

Clinical impact of tumor-infiltrating inflammatory cells in primary small cell esophageal carcinoma

Primary small cell esophageal carcinoma is a rare and aggressive type of gastrointestinal cancer with poor prognosis. In the present study, the impact of tumour infiltrating inflammatory cells on clinico-pathological characteristics and the patients' prognosis were analysed. A total of 36 small cell esophageal carcinomas, 19 adjacent normal tissues and 16 esophageal squamous cell carcinoma samples were collected. Qualified pathologists examined eosinophils, neutrophils, lymphocytes and macrophages on histochemical slides. The infiltration of eosinophils and macrophages in small cell esophageal carcinoma was significantly increased as compared with tumor adjacent normal tissues, and was significantly less in esophageal squamous cell carcinoma. Macrophage count was significantly associated with (p = 0.015) lymph node-stage in small cell esophageal carcinoma. When we grouped patients into two groups by counts of infiltrated inflammatory cells, Kaplan-Meier analysis revealed that high macrophage infiltration group (p = 0.004) and high eosinophil infiltration group (p = 0.027) had significantly enhanced survival. In addition, multivariate analysis unveiled that eosinophil count (p = 0.002) and chemotherapy (Yes vs. No, p = 0.001) were independent prognostic indicators. Taken together, infiltration of macrophages and eosinophils into the solid tumor appear to be important in the progression of small cell esophageal carcinoma and patients' prognosis.