Squash Smear Research Articles

Role of intraoperative squash smear cytology as a diagnostic modality in lipoma of quadrigeminal cistern

Quadrigeminal lipoma is a rare tumor that has been categorized as developmental malformation rather than a hamartoma or true neoplasm, due to its origin from abnormal persistence and mal-differentiation of meninx primitiva during the development of the subarachnoid cisterns. Reported admixture of adipose tissue with heterotopic elements also supports a developmental origin. Quadrigeminal lipomas are frequently asymptomatic and detected incidentally. Though a favorable clinical course is usually expected, recurrences may occur due to partial removal of lesions in close relation to vital structure. We describe the role of intraoperative squash smear cytology as a diagnostic aid in quadrigeminal cistern lipoma and an alternative to frozen sections that are technically difficult to obtain due to presence of lobules of fibro-adipose tissue. With radiological correlation, squash cytology can be an economical method for intraoperative diagnosis, pending subsequent histopathological confirmation.

Analysis of Squash Smear Cytology of Ependymomas

Background: Ependymomas constitute 8–10 and 1–3% of central nervous system tumors in children and adults, respectively. Though intraoperative squash smear cytology is well documented, grading is rarely described. Objectives: (1) To assess cytomorphology and grade ependymomas in squash smears. (2) To compare utility of hematoxylin and eosin (H&E) and toluidine blue (TB) staining. Study Design: Ependymomas diagnosed from 2004 to 2010 were retrieved from pathology records. Intraoperative squash smears stained with TB and H&E were studied. Results: Histological sections of 29 ependymomas were graded according to WHO 2007 classification. There were 3 myxopapillary (grade I), 13 grade II, and 13 grade III (anaplastic) ependymomas. Perivascular pseudorosettes were seen in 23 smears, and 11 showed rosettes. Less cohesive cells at the periphery of fragments with unipolar cytoplasmic processes were seen in all smears. The background was fibrillary in all except in myxopapillary ependymoma. Metachromatic material was seen in myxopapillary ependymoma around vessels and in globi. The nucleus was round with stippled chromatin and 1–2 small nucleoli could be seen. All smears of grade III ependymomas showed pleomorphism, mitoses, microvascular proliferation and necrosis. Conclusion: Ependymomas can be diagnosed and graded reliably by squash smear. Myxoid stroma was better appreciated by TB staining. TB and H&E complement each other in squash smears for cytomorphology.

Cytologic Features of Giant Cell Ependymoma: A Case Report and Review of the Literature

Here, we present a case of anaplastic giant cell ependymoma (GCE) occurring in a 15-year-old woman. Squash smear slides for intraoperative frozen section diagnosis revealed oval to round cell clusters with a papillary structure in a fibrillary background. This was occasionally accompanied by the presence of bizarre pleomorphic giant cells with hyperchromatic nuclei and prominent intranuclear inclusions. These intranuclear inclusions were a key clue to diagnosis of ependymoma. Histologic analysis revealed features of a high-grade tumor with perivascular pseudorosettes and bizarre pleomorphic giant cells, which established the diagnosis of GCE. We performed a review of literatures about the cytologic features of GCE, including our case, thus proposing that intraoperative frozen diagnosis of GCE would be established by squash smear preparations featuring the mitosis and necrosis, as well as the high cellularity, and the presence of giant cells showing hyperchromatic nuclei with eosinophilic cytoplasm and intranuclear inclusions/pseudoinclusions.

Cytopathologic characteristics of the primary strumal carcinoid tumor of the ovary: A case report with emphasis on differential diagnostic considerations

Primary strumal carcinoid tumor of the ovary (SCTO) is an extremely rare entity, though the survival rate is excellent if the disease is confined to one ovary. A case is presented here in which intraoperative squash smears in a 45-year-old woman with a left adnexal mass revealed dispersed or small clusters of neoplastic cells forming loosely cohesive gland-like structures with abundant cytoplasm. The nuclear chromatin was finely granular with a "salt and pepper" appearance and occasional tiny nucleoli. The position of the nucleus presented a vaguely plasmacytoid appearance. Small fragments of thyroidal colloid-like structures were also identified. A cytopathologic diagnosis of a SCTO was suggested. Further evaluation and immunohistochemical studies were conducted on formalin-fixed, paraffin-embedded material. Cords or nests of uniform cells with abundant cytoplasm, and eccentric nuclei with coarse chromatin and occasional colloidal tissue were identified on H&E sections. The tumor cells showed diffuse and strong cytoplasmic staining for chromogranin A, synaptophysin, CD56, and vimentin but were negative for calretinin, α-inhibin or CDX2. The proliferative index with MIB-1 was around 3%. Thyroidal colloid-like structures were immunoreactive for thyroglobulin and TTF-1 stains. The diagnosis of primary SCTO was confirmed based on cytopathologic, histopathological, and immunohistochemical results, and the location of the tumor. Awareness of the cytopathological findings of SCTO can assist in diagnosing this rare entity correctly.

Cytopathologic findings and differential diagnostic considerations of primary clear cell carcinoma of the lung

Primary clear cell carcinoma (CLCC) of the lung is an extremely rare disease and is a subtype of large cell carcinoma, according to the World Health Organization (WHO) classification. A case is presented here in which intraoperative squash smears in a 53-year-old man revealed sheet and small clusters or tumor cells with prominent nucleoli and fine granular chromatin. Abundant translucent cytoplasm with occasional cytoplasmic vacuoles and intracytoplasmic eosinophilic inclusions was also identified. A cytopathologic diagnosis of a CLCC was suggested. Further evaluation and immunohistochemical studies were conducted on formalin-fixed, paraffin-embedded material. Nests of slightly acidophilic clear tumor cells with a prominent cellular membrane and an alveolar growth pattern were identified on H&E sections. Immunohistochemically, the tumor cells showed diffuse and strong membranous staining for CK(AE1/AE3), CK7, and CA19-9 but were negative for Napsin A, CK20, CDX2, TTF-1, alpha-fetoprotein, chromogranin A, synaptophysin, CD10, and CD56. The diagnosis of primary CLCC of the lung was confirmed based on cytopathologic, histopathologic, immunohistochemical results, and a detailed systemic examination to exclude a possible extrapulmonary origin. We report here the cytopathological features of CLCC of the lung with an emphasis on differential diagnostic considerations.

Intraoperative squash cytology: accuracy and impact on immediate surgical management of central nervous system tumours

To assess the diagnostic accuracy of squash cytology, reasons for deferment, disagreement and partial agreement, and assess its impact on immediate surgical management of central nervous system tumours. All cases of squash cytology received from January 2007 to July 2010 were reviewed and correlated with final histopathological diagnoses. Deferments, disagreements and partial disagreements were reviewed to look for possible reasons. The impact of disagreements and partial agreements on immediate surgical management was evaluated in consultation with neurosurgeons. Overall accuracy (including complete and partial agreement) for squash smear diagnosis of 334 cases was 94.9% while complete agreement was 79.9%, excluding deferred cases. Disagreement was seen in 17 cases and 31 cases were deferred for final histopathology diagnosis. Good correlation was seen in astrocytoma, meningioma, schwannoma, medulloblastoma, pituitary adenoma and metastatic carcinoma, whereas poor correlation was seen in oligodendroglioma, ependymoma and lymphoma. Among 17 cases with disagreement and 50 cases with partial agreement, an adverse impact on immediate surgical management was found in six (35.3%) cases and one (2.0%) case, respectively. The sensitivity and specificity of squash for diagnosis of neoplastic lesions were 98.7% and 87.5%, respectively. Squash cytology is a rapid, reliable, simple technique for intraoperative consultation in neurosurgical practice with high overall accuracy. Causes causing an adverse impact on surgical management were rare and potential avoidable reasons for them were identified.

Cytomorphology of giant cell glioblastoma: Report of a case and brief review of literature

Giant cell glioblastoma is a histological variant of glioblastoma that accounts for less than 1% of intracranial tumors and to 5% of glioblastoma. They occur at any age and are likely to affect the younger as well the older age group unlike the conventional glioblastoma multiforme (GBM). They are often located subcortically in the temporal and parietal lobes. Cytological descriptions of giant cell glioblastoma are extremely rare. We describe squash cytomorphology of giant cell glioblastoma of left posterior frontal region in 35-year-old male. The squash smears were moderately cellular displaying malignant astrocytic tumor cells disposed in cohesive clusters and dispersed population on a necrotic background. Most striking feature was numerous multinucleated giant cells. We also discuss the differential diagnosis in light of relevant literature.

Squash cytomorphology of central neurocytoma: A study of five cases

Intraoperative consultation is an important component in the surgical management of brain tumors. This study was undertaken to describe the cytomorphological features of central neurocytoma (CN) in squash smears. Squash smear of five CNs were reviewed. One to two millimeters of the biopsy material was crushed between two glass slides to make a thin film that was fixed in 95% alcohol and stained with haematoxylin and eosin (H&E). Cytological diagnoses were correlated with clinical and radiological data and finally with histopathological findings in the tumor. We had 5 cases (4 males, 1 female; age, 19-61 years; mean, 32 years). All tumors were located in the lateral ventricle. The smears were highly cellular displaying monomoprhic round tumor cells, round to oval nuclei with evenly distributed finely granular chromatin and ill-defined cytoplasmic borders within fibrillar matrix. Focal rosette formation is also noted. A capillary network was identified in between tumor cells in all the cases. One case had calcification with numerous psamomma bodies identified in the squash smear. The differential diagnosis is discussed. On squash smears, CN can be diagnosed when cytomorphological features are correlated with clinical and radiological finding.

Cytopathologic characteristics and differential diagnostic considerations of neuroglial heterotopia of the retropharyngeal space

Neuroglial heterotopias (NGH) are rare congenital head and neck lesions composed of differentiated neuroectodermal tissue and representing developmental heterotopias rather than true neoplasms. The case of a male neonate with respiratory distress and early feeding problems depicting a retropharyngeal space mass which in the intraoperative squash smears revealed glial cells with multiple cytoplasmic processes is reported here. Small clusters of cuboidal epithelial cells with rosette-like ependymal structures and cuboidal cells arranged in sheets or branching folds suggestive of choroid plexus cells were also identified. Through this cytological approach a cytologic diagnosis of a NGH or low-grade astrocytoma was suggested. Further evaluation and immunohistochemical studies were conducted on formalin-fixed, paraffin-embedded material. Glial cells, ependymal structures and choroid plexus were identified on H&E sections. Immunohistochemically, the glial cells showed diffuse and strong cytoplasmic staining for glial fibrillary acidic protein (GFAP) and S-100 protein and focal immunoreactivity for synaptophysin and neurofilament. The proliferative index with MIB-1 was around 4%. The diagnosis of NGH of the retropharyngeal space was confirmed based on the clinical, cytopathologic, histopathology, immunohistochemical results, and the location of the tumor. We demonstrated here for the first time the cytopathological features of NGH of the retropharyngeal space with emphasis on differential diagnostic considerations.

Squash cytology of subependymal giant cell astrocytoma: Report of four cases with brief review of literature

Squash cytology description of subependymal giant cell astrocytoma (SEGA) is poorly described in the literature. Objective of this study is to study the cytomorphological features of SEGA in squash smears. Introperative squash smear preparations of four patients of SEGA diagnosed from 2004 to 2010 were reviewed. One to two millimetres of the biopsy material was crushed between two glass slides to make a thin film and fixed in 95% alcohol and stained by haematoxylin and eosin (H&E). Smear cytology diagnoses were correlated with clinical, radiological data and finally with histopathological findings of the tumor specimen. We had four cases (all males; age range 11-15 years; mean age 12.5 years). All tumors were located in the lateral ventricles. The cytological smears in all four cases were cellular and display pleomorohic binucleate to multinucleate tumor cells disposed in cohesive clusters, groups or lying singly. Elongated spindle shaped and strap cells with long thick cell processes were also identified. On squash smears, SEGA can be diagnosed when cytomorphological features are correlated with clinical and radiological finding. The distinct cytomorphological features are cellular smears comprising of pleomorohic binucleate to multinucleate tumor cells with round to polygonal eccentrically placed mildly anisomorphic nuclei, prominent nucleoli, and abundant eosinophilic glassy cytoplasm. Astrocytic fibrillary background, endothelial proliferation, mitosis, and necrosis are lacking.

Characteristics of tumour vessels in cytological squash smears of astrocytic tumours

Smear preparations are useful tools from which to diagnose brain tumours intraoperatively. Although vascular proliferation is histologically a key feature of high-grade astrocytoma, the characteristics of tumour vessels in smear preparations have not been determined. We examined the density and morphological parameters (area, width, nuclear layer and branches of vessel wall) of tumour vessels in squash smears of 43 primary astrocytomas (grade II diffuse astrocytomas, n=9; grade III anaplastic astrocytomas, n=13; grade IV glioblastomas, n=21) and normal brain tissues (n=11). Vessel density and all morphological parameters were significantly higher in grade IV than in the other grades of tumours and in normal brain tissue. Vessel area, width and nuclear layer were greater in grade III than in normal brain tissue. The sensitivity and specificity of these vessel parameters for astrocytomas were 75-100% and 82-100%, respectively. Tumour vessel evaluations from squash smears provide useful information for the intraoperative diagnosis and grading of astrocytic tumours.

Rhabdoid meningioma: Rapid intraoperative diagnosis on squash smears

Rhabdoid morphology in tumors refers to resemblance of the cells to rhabdomyoblasts without true skeletal muscle differentiation. The cytological features include abundant eosinophilic cytoplasm, eccentric nuclei, and intracytoplasmic hyaline inclusions. Besides the rhabdoid morphology, cytoarchitectural features of atypical meningioma (four or more mitoses per 10 high-power fields, high cellularity, sheeting architecture, nuclear atypia, and necrosis) are seen in most cases. A case is presented here to highlight the appearance of rhabdoid cells on intraoperative squash smears, for most accurate treatment and close follow-up, as rhabdoid morphology is related to aggressive behavior and poor outcomes.

Cytopathological features of warty (condylomatous) carcinoma of the penis: A case report and distinction from other verruciform penile tumors

Warty (condylomatous) carcinoma (WC) is a rare specific variant of invasive squamous cell carcinoma that shows hybrid features of condyloma with invasive cell carcinoma. As compared with conventional squamous cell carcinoma, WC tends to run a less aggressive clinical course. A case is presented here in which squash smears of a penile foreskin tumor in a 65-year-old male revealed small cohesive clusters and sheets of tumor cells in papillary configurations. The neoplastic cells were polygonal to elongated and contained oval nuclei, coarse chromatin pattern, and distinct nucleoli. Nuclear pleomorphism and loss of nuclear polarity were observed. Characteristically, there were also many koilocytes demonstrating mild to moderate nuclear atypia and perinuclear cytoplasmic halos. A cytologic diagnosis of a verruciform penile tumor was suggested. Histologic examination of the tumor showed a hyper-parakeratotic arborizing papillomatous growth with thin fibrovascular cores and the tips were variably rounded or tapered. Obvious koilocytic cytopathic change, nuclear pleomorphism, and focal stromal invasion were observed. Immunohistochemically, the tumor cells showed diffuse and strong membranous staining for cytokeratin (AE1/AE3) while the MIB-1 and p53 immunoreactive cells were confined to the basal areas of the papillae. No lymphovascular invasion was detected in D2-40 or elastic Van-Gieson stains. On the basis of the overall features, we confirmed a final diagnosis of penile WC. We demonstrated here for the first time the cytopathological features of penile WC with emphasis on differential diagnostic considerations.

Cytopathologic features of orbital intraosseous chordoid meningioma: Report of a case and distinction from other myxoid/mucoid tumors

Chordoid meningioma (CM) is characterized by a striking histologic resemblance to chordoma and propensity for aggressive behavior or recurrence (WHO grade II designation). Orbital intraosseous CM is extremely uncommon and only one case report has been documented. A case is presented here in which squash smears of a left orbital tumor in a 53-year-old male revealed small clusters or cord-like structures of bland tumor cells embedded in a myxoid or mucinous background. Whorl-like structures were also identified. The tumor cells possessed uniformly round nuclei with a smooth nuclear outline, fine granular chromatin, and small nucleoli. Occasional intranuclear inclusions, coarse collageneous cytoplasmic filaments were observed. Many spindle-shaped cells with similar nuclear findings were also seen. A cytologic diagnosis of a chordoid meningioma was suggested and histochemical and immunohistochemical studies were conducted on formalin-fixed, paraffin-embedded material. Immunohistochemically, the tumor cells showed diffuse and strong membranous and cytoplasmic staining for vimentin, epithelial membrane antigen (EMA) and faintly reactive with S-100 protein but negative for pan-neuroendocrine markers (i.e., NSE, chromogranin A, synaptophysin), cytokeratin AE1/AE3, smooth muscle actin, D2-40, brachyury or class III beta-tubulin. The proliferative index with MIB-1 was less than 1%. The diagnosis of orbital intraosseous CM was confirmed based on cytopathologic, histopathological, immunohistochemical results, location of the tumor, and the lack connection to the duramater. We demonstrated here for the first time the cytopathological features of intraosseous CM with emphasis on differential diagnostic considerations.

Evaluation of the Squash Smear Technique in the Rapid Diagnosis of Central Nervous System Tumors: A Cytomorphological Study

Objectives: To compare the squash smear technique with the histopathological examination in the diagnosis of Central Nervous System (CNS) gliomas and to assess the utility of the squash smear technique for the rapid diagnosis in the neurosurgical biopsies for real time intraoperative consultation. Methodology: This was a prospective study conducted in the Department of Neuropathology of Sir J.J. hospital for a period of 6 months. Fifty cases of radiologically suspected CNS gliomas were sent for intraoperative smear cytology and subjected to both histopathological examination and squash smear cytology. The two techniques were then compared for their ability to diagnose as well as grade the tumor. Appropriate statistical analysis methods were then applied to the findings. Results: Smear cytology and histopathology diagnoses were compared. The following values were obtained: accuracy of 88%, sensitivity of 91.6%, specificity and positive predictive value of 100%. Conclusion: Intraoperative cytological diagnosis is fairly accurate, safe, simple, reliable and cost effective tool for rapid diagnosis of CNS gliomas and is of great value in intraoperative consultation of CNS tumors.

Tumor irrigation fluid enhances diagnostic efficacy in endoscopic biopsies of intracranial space-occupying lesions

Intraventricular neuroendoscopic CNS biopsiesare small, fragmented, and tissue is frequently inadequate for diagnosis. We have attempted to increase cellular yield using tumor irrigation fluid (TIF) and a cyto-histological approach for diagnosis of intracranial tumors, cysts, and infections. A retrospective group of 147 cases, where only endoscopic biopsies were obtained, was compared with a prospective group of 31 cases where along with the endoscopic biopsies, tumor irrigation fluid (TIF) was collected. Tumor cyst fluid was obtained from cystic tumors (n=6). Small tumor fragments in the TIF were utilized to make squash smears (n=31). Clotted fragments were processed for sections in (n=3). Centrifuged deposit smears were prepared from tumor irrigation fluid and tumor cyst fluid. Conclusive pathological diagnosis in endoscopic biopsies could be arrived at in 77.4% (24/31) prospective cases and 80.3% (118/147) in retrospective cases. Collection of TIF with a cyto-histological diagnostic approach gave a significantly higher rate of conclusive pathological diagnosis in 93.5% (29/31) cases in the prospective group. Additional tissue from TIF preserves the original biopsy, provides more material for diagnosis and gives a better morphological picture in smears. Hence diagnosis of endoscopic CNS biopsies can be rendered in more cases and with greater degree of confidence.

Cytopatholologic features of gliosarcoma with areas of primitive neuroepithelial differentiation of the brain in squash smears

Gliosarcoma with areas of primitive neuroepithelial differentiation (GSPNED) is an extremely rare neoplasm. A case is presented here in which squash smears of a left temporal lobe tumor in a 76-year-old male demonstrated two distinct and easily recognizable cellular populations, i.e., densely hyperchromatic cells of a primitive nature in a fibrillary background and pleomorphic spindle-shaped cells. Occasional pseudo-rosette formations and nuclear cannibalism suggestive of neuroendocrine differentiation were also found. A cytologic diagnosis of a malignant tumor was suggested, and histochemical and immunohistochemical studies were conducted on formalin-fixed, paraffin-embedded material. Reticulin stain highlighted increased intercellular collagen and reticulin deposition within the spindled regions, whereas nodules with primitive cells were reticulin-poor. There was a diffuse and strong reactivity to neuron specific enolase, synaptophysin and CD56 immunostains. A stain for glial fibrillary acidic protein and S-100 protein demonstrated a subset of tumor cells including elongated cytoplasmic processes. The spindled component was positive for vimentin and smooth muscle actin, whereas the primitive-appearing tumor cells were negative. The diagnosis of GSPNED was confirmed based on cytopathologic, histopathological and immunohistochemical results. The cytomorphologic features of this distinctive tumor are illustrated, and the adjunctival value of squash smears for frozen-section diagnosis is also discussed. This is the first presentation of a cytopathologic analysis that provides an important clue to an accurate diagnosis of GSPNED.

Cytomorphologic manifestations of Alzheimer's disease using brain squash smears: An autopsy study with histology–cytology correlation

Alzheimer's disease (AD) is the most common form of dementia. The cardinal histopathologic features include senile plaques (SPs) and neurofibrillary tangles (NFTs), and in addition, granulovacuolar degeneration (GVD) and Hirano bodies (HBs) are frequently observed in the hippocampus. We studied hippocampal cytological features of AD, compared with controls. Hippocampal squash smears were prepared from 26 autopsy brains and stained with three different solutions, including Papanicolaou stain (Pap-s). The smears were evaluated for the aforementioned four structures and gliosis, and their frequency was compared between AD (n = 15) and control (n = 11) groups. Hippocampal smears of all AD cases revealed NFTs and gliosis. NFTs were light gray with thick flame-like structures on Pap-s. GVD was identified in the majority of AD cases and was most easily observed on Pap-s. SPs were difficult to identify and were seen only in AD cases. HBs were rarely identified as long light eosinophilic hyaline structures on Pap-s. Cytological findings of hippocampi reflect the characteristic histological features of AD with the exception of HBs, which are difficult to identify on smears. NFTs and gliosis, and SPs seem to be sensitive and specific cytologic markers in hippocampal smears for AD, respectively.

Endoscopic diagnosis of a pineal papillary glioneuronal tumor with extensive ventricular involvement: Case report with review of literature

Papillary glioneuronal tumor (PGNT) is a newly described mixed glioneuronal tumor, recently included in the World Health Organization classification of central nervous system tumors. We report morphologic and immunohistochemical characteristics PGNT of the pineal region extending into the third and lateral ventricles in a four-year-old male child and reviewed all the cases reported in the international literature till date. In this child the diagnosis of PGNT was established by endoscopic biopsy and squash smear examination.

The reservoir status of rabbits for the maintenance of <i>Ehrlichia ruminantium</i>

The reservoir status of rabbits for a strain of Ehrlichia ruminantium was investigated using six experimental and four controlled rabbits. Each of the experimental animals was intraperitoneally inoculated with 1.5 ml of infective blood from a febrile goat. The effect of the parasite on body weight, packed cell volume, total protein and daily morning rectal temperature was monitored. Analysis of variance (ANOVA) revealed significant differences (p < 0.05) in packed cell volume, total protein and daily morning rectal temperature between the experimental and controlled rabbits. However, LSD test showed no differences between the samples. Following apparent non-reaction to the parasite after 28 days, 4 ml of pooled whole blood from the experimental rabbits was used to inoculate a susceptible goat in order to ascertain the potency of the parasite. The goat died after 15 days and brain squash smears prepared were positive for Ehrlichia ruminantium. The results of the current study indicate that rabbits might harbour the parasite without coming down with infection while retaining its infectivity. The study, therefore, suggests that rabbits might be useful in the maintenance of Ehrlichia ruminantium. Keywords: rabbits, reservoir status, Ehrlichia ruminantium. Nigerian Journal of Parasitology Vol. 29 (2) 2008: pp. 67-71