Cytological features of diffuse and circumscribed gliomas

The current World Health Organization classification of gliomas is based on morphological, genetic, and molecular parameters. In this review, we intend to present the most relevant cytological features of these tumours, with a particular focus on their analysis during intraoperative studies. Rapid diagnosis is required in this context, and at present it is not possible to evaluate the genetic or molecular profile of a tumour intraoperatively. New terminology and diagnostic parameters have been introduced, but the essence of intraoperative recognition remains the same. The main challenge in astrocytoma IDH-mutant, grade 2 is recognising the tissue as neoplastic. Since glioma grades 3 and 4 are assigned based on histological and genetic variables that are not necessarily measurable on cytology, the term high-grade glioma is often used for intraoperative diagnosis. Oligodendroglioma, IDH-mutant and 1p/19q-codeleted shows peculiar cytological findings as well as the common subtypes of glioblastoma IDH-wildtype (giant cell, epithelioid, gliosarcoma and small cell). Many of the paediatric-type-diffuse gliomas have been described very recently and there are no cytological reports of proven cases. Finally, pilocytic astrocytoma, pleomorphic xanthoastrocytoma, subependymal giant cell astrocytoma, chordoid glioma, and astroblastoma MN1-altered constitute the group of circumscribed astrocytic gliomas. They are remarkable entities that the pathologist must be able to recognise since most are low-grade neoplasms that can show atypical morphological features.

Visual Acuity Improvement in Low, Moderate and High Myopia After Posterior-Chamber Phakic Implantable Collamer Lens Surgery in a Large Patient Cohort

Purpose

To compare best-corrected visual acuity (BCVA) before and after implantable collamer lens (ICL) surgery in patients with low, moderate and high myopia.

Methods

A single-centre, prospective, registry-based study involving patients with myopia who received ICLs between October 2018 and August 2020. The study population was divided into three groups of subjects with low (from 0 to -6 D), moderate (-6 to -10 D) and high myopia (more than -10 D). We analysed uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent (SE), differences between BCVA pre- and 1-month postoperative, and line gain in BCVA 1 month after surgery.

Results

A total of 770 eyes belonging to 473 patients were surgically intervened during the study period, of which 692 eyes completed 1 month of postoperative follow-up and were included in the study population. At 1-month follow-up, 478 eyes (69%) achieved a BCVA of 20/20, 599 (87%) obtained 20/25 or better, and 663 (96%) had a BCVA of 20/40 or better. We identified a significant improvement in BCVA (baseline 0.15±0.2 logMAR vs follow-up 0.07±0.2 logMAR, p<0.0001) and a significant reduction in SE (baseline -9.23±4.1 D, vs follow-up -0.21±0.8 D, p<0.0001), with a significant relationship between preoperative SE and line gain (r = -0.46, p<0.0001). We identified a significantly higher line gain among eyes with higher degrees of myopia (low myopia 0.22±0.69 lines compared to moderate myopia 0.56±1.1 lines and high myopia 1.51±1.9 lines, p<0.0001). Notably, 99.6% of eyes with a high grade of myopia achieved improvement to a low degree (less than -6 D) at follow-up. The safety and efficacy indexes were 0.083±0.1 and -0.001±0.1, respectively.

Conclusion

In this large patient cohort, ICL surgery was related to a significant line gain in BCVA, particularly among eyes with higher degrees of myopia.

A comprehensive review of the "tigroid" background cytological concept: what, when, where and why?

The concept of “tigroid” background is used in cytology to describe a peculiar smear background characterized by the presence of a relatively granular, reticulated material that was described as “foamy, lazy, tiger-striped or astrakhan”. It was used to describe the background seen in smears obtained from seminoma. In addition to seminoma, we now know that it can be present in different tumours, mostly carcinomas and round cell sarcomas. These share with seminoma a cytoplasm with high glycogen content and many times clear cell morphology. The “tigroid” background is seen when smears are air-dried and Romanowsky-based stains are used (May-Grunwald-Giemsa and Diff-Quik stains). It is only seen in fine needle aspiration or intraoperative squashing or scrapping samples, but not in specimens obtained from effusions or liquid-based cytology. Wet-fixed cytologic samples with alcohol or with formaldehyde tend to dissolve the background so it is not usually present in Papanicolaou stained smears. In this review, we discuss tumours in which the “tigroid” background is observed and its potential diagnostic utility and aetiology. It is interesting to remark that except for parathyroid adenoma and adenomatoid tumour all the neoplasms in which this background has been observed are malignant.

Fine needle aspiration cytology of a myxoid adrenocortical adenoma. A case report

The myxoid variant of adrenocortical (AC) tumors is characterized by peculiar histologic features that differ from conventional ones. It shows a prominent myxoid stromal component and is composed of small cells with mild atypia arranged in cords, pseudoglandular structures and microcysts. Reflecting the rarity of this variant, very few cytologic descriptions are available. We describe one case in a 41-year-old woman with a previous diagnosis of breast carcinoma and BRCA1 mutation. During follow-up controls, an adrenal tumor was discovered. Fine needle aspiration cytology and Tru-Cut biopsies were performed simultaneously. Smears showed numerous groups of cohesive cells of intermediate to small size. Within the largest groups, aggregates of myxoid metachromatic material were evident. This myxoid material could also be observed as isolated acellular fragments. While the cytoplasm of most tumoral cells was homogenously stained some showed small vacuoles. Histologically, the tumor grew, forming anastomosing cords, separated by myxoid material that determined microcystic spaces. Immunohistochemistry was characteristic of AC myxoid tumor. After surgery, pathologic analysis confirmed this diagnosis. The tumor showed no necrosis or invasion, had a low mitotic index (3/50 high power fields) and Ki-67 proliferative index of 15%. According to the different diagnostic systems the tumor was classified as an adenoma. In conclusion, the myxoid variant of AC tumors shows peculiar cytologic features. If unaware of the existence of this variant, it can easily be misinterpreted as a metastatic tumor.

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.

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.