Squash Smear Research Articles

Intraoperative cytology (squash smear) in neurosurgical practice – pitfalls in diagnosis experience based on 3057 samples from a single institution

The smear technique is challenging for a neuropathologist where rapid and accurate diagnosis is to be given on small biopsies. The present study, a large retrospective analysis of squash smears in neurosurgical practice, was conducted to assess the usefulness, accuracy and the diagnostic pitfalls of smear diagnosis. The authors analysed 3057 central nervous system (CNS) lesions sent for intraoperative cytology (IC) during the years 1988-2005. The stain used was 1% alcoholic toluidine blue. The smear diagnosis was compared with the histological diagnosis to evaluate the diagnostic accuracy. Diagnostic accuracy irrespective of lesion and site ranged from 83.0% to 86.0% per year (mean=85%). The highest rate of correlation among common brain tumours was noted in schwannoma (96.6%) and pituitary adenoma (92.2%), followed by meningiomas (88.9%), astrocytomas (88.4%), chordomas (86.4%) and neurocytomas (86.9%). Infections as a whole contributed 380 cases. The most common infection was tuberculosis. This is the largest series reported from India to the best of our knowledge. Squash smear technique is a very reliable and rapid method of intraoperative diagnosis. Knowledge of clinical and neuroimaging details helps the experienced neuropathologist to improve the diagnostic accuracy.

Cytology of chordoid meningioma: a series of five cases with emphasis on differential diagnoses

Background: Chordoid meningioma is a rare meningioma variant characterised by epithelioid cord-like tumour cells in a myxoid stroma. It is classified as grade II (World Health Organization) tumours, as they...

Middle and posterior fossa aspergilloma

Background Aspergilloma of the brain is a rare disease. Among its varied presentations, a solitary intracranial mass is very uncommon. A preoperative diagnosis of it is very difficult, but a perioperative squash smear/frozen section can identify the pathology. Because of its rarity in immunocompetent patients and the difficulty in preoperative diagnosis, we have illustrated this case and its presentation and management. Methods A 27-year-old man presented with an h/o right-sided weakness along with headache and ear discharge. A computed tomographic (CT) scan showed a large irregular, space-occupying lesion in the middle and posterior cranial fossa. He had a mastoidectomy done 3 years before for chronic suppurative otitis media. After a symptom-free interval of 1 year, he was investigated for severe earache on the same side. A CT scan at that time showed a space occupying mass in the right temporal bone and right inferior temporal lobe. A biopsy and histopathology of the lesion revealed a chronic granulomatous mass. He was started on antituberculous drugs and was on it for 7 months at the time of presentation. Results He underwent a suboccipital craniectomy and total excision of the mass. Postoperatively, his consciousness improved but began to deteriorate on the third postoperative day. A repeat CT scan showed hydrocephalus and total removal of the mass. An external ventricular drain was put and he was ventilated, but he died on the fourth postoperative day. Histopathology report came as aspergilloma. Conclusion This report highlights the rare presentation of aspergilloma in an immunocompetent patient. It emphasizes the importance of suspecting this disease in such patients and the role of intraoperative squash smear preparations or frozen section in the diagnosis as routine diagnostic procedures that will help in early pharmacotherapeutic interventions in adjunct to surgery.

Application of immunohistochemistry to CSF and squash smears of lesions of nervous system

Application of immunohistochemistry to CSF and squash smears of lesions of nervous system

Squash smears - Rapid diagnostic tool for neurosurgical biopsies

Squash smears - Rapid diagnostic tool for neurosurgical biopsies

Diagnostic efficacy of stereotactic biopsies in intracranial tuberculomas

BACKGROUND Stereotactic biopsies for diagnosing intracranial tuberculomas are often reported to be inconclusive, being confirmatory in only 28% of cases. We analyzed the role and diagnostic efficacy of stereotactic biopsies in the management of intracranial tuberculomas. METHODS Twenty patients diagnosed with intracranial tuberculomas based on neuroimaging procedures underwent computerized tomography (CT) guided stereotactic biopsies for histological confirmation. In 10 patients (Group A), biopsies were obtained from the center of the lesion; in the other 10 (Group B), biopsies were obtained from both the enhancing rim and the isodense center and examined separately. The tissues were processed for paraffin sections and hematoxylin eosin staining. In addition, in the first five patients a squash smear from a small portion of the biopsy was prepared, and the cytological features of the cells were examined. All the patients received antitubercular medication and CT scans were repeated 4 months posttreatment. RESULTS Histopathological features of the paraffin sections in 17 patients (Group A: 8, Group B: 9) were diagnostic of tuberculoma, whereas the other three revealed only chronic nonspecific inflammation. Based on the cytological features in squash smears, diagnosis could be made in one of five. In two, although the smear was not diagnostic, the histological section from the same specimen confirmed the tuberculous pathology. There was no procedural morbidity or mortality. One patient had a small asymptomatic hematoma at the biopsy site. Three patients died during the follow-up period, due to secondary complications of tuberculosis. Repeat CT scans during follow-up after antituberculous treatment confirmed the reduction in the size of the lesion in 15/17 patients. CONCLUSION The high positive yield of stereotactic biopsies in diagnosing tuberculomas argues for their inclusion in the management protocol for tuberculous mass lesions.

Squash Preparation and Frozen Section in Intraoperative Diagnosis of Central Nervous System Tumors

To investigate the diagnostic accuracy of squash preparation (smears) and frozen section (FS) in the rapid intraoperative diagnosis of central nervous system (CNS) tumors. One hundred eighty-three CNS tumors were examined over a period of 18 months (January 1995-June 1996). All these were open biopsies, and the smear interpretation was compared with FS findings and paraffin section diagnosis. In 183 tumors, squash preparation was satisfactory in 156 cases (85.2%), and the diagnostic accuracy was 89.7% (140/156). The accuracy of FS diagnosis was 90.4% (141/156). The squash smear preparation is a fairly accurate and reliable tool in the rapid intraoperative diagnosis of CNS tumors. The accuracy of this technique is nearly as good as that of FS (P value = .9877). With the advent of stereotactic biopsies, the pathologist may have to depend entirely upon cytologic features for a definitive diagnosis.

Influence of smear preparation and fixatives on the DNA ploidy and the morphonuclear features of the MXT mammary tumor and normal tissues in the mouse

We compared cytomorphonuclear parameters--related to DNA histogram and chromatin distribution--on MXT mouse mammary tumor and murine normal cells from fresh squash smears or from deparaffinized tissue smears fixed in several fluids. We used the SAMBA 200 cell image processor with software allowing for the discrimination of parameters computed on Feulgen-stained nuclei. The spectrophotometric results--assessed by integrated optical density values--indicate that the nuclei from deparaffinized tissue fixed in Bouin's fluid are around 50% less stained than those fixed in formalin or ethanol-formalin-acetic acid (EFA). The fresh smears of nuclei fixed in formalin contain a less well-defined and more homogeneous chromatin than after Bouin's or EFA fixation. This has led to the conclusion that morphonuclear parameter comparisons performed on tissues differently processed or from different origins present severe limitations.

EVALUATION OF MEGAKARYOCYTES IN CHILDHOOD IDIOPATHIC THROMBOCYTOPENIC PURPURA (ITP)

The clinical course of ITP in children usually differs from that in adults, yet distincttons by marrow characteristics have not been established. Megakaryocytes (megas) were examined for size, ploidy, maturation and morphology in 8 children and 8 adults with ITP, and 8 normal marrows. Either buffy coat wedge or cover slip squash smears were prepared. (Control values differed for each.) Feulgen-stalned megas (100-300) were examined as previously described. Wright-stained material was also examined. There were no differences in the megas of normal children and adults. In all children with acute ITP, megas were increased in size (mean volume 4X normal), ploidy (medians 2 doublings higher, to 64N) and maturation stage (86% mature vs control 43%). In contrast, In adults with acute or chronic ITP the megas showed no differences In size, ploidy, or maturation compared to controls. Some dissociation of mega ploidy and maturation was seen in adults, but not enough to alter the profile of any one parameter. In conclusion, the megas of acute childhood ITP were different than adults'. Similar enlargement and maturation is seen in animals whose megas are stimulated by injection of anti-platelet serum. The absence of these large, mature megas in adult ITP may reflect the chronicity of this disease In adults. Studying children with chronic ITP with regard to marrow mega characteristics may provide information to help identify those children with acute ITP with a propensity to develop chronic ITP.

An acute septicemic infection of Pasteurella organism in pond-cultured Formosa snake-head fish (Channa maculata Lacepede) in Taiwan.

In March 1983, an acute bacterial septicemic infection in fresh water pond-cultured Formosa snakehead fish (Channa maculata Lacepede) outbroke in Pingtung Hsein, Taiwan. The affected fish showed no apparent surface lesions, nevertheless, sudden listlessness and subsequent death at the bottom of the pond were the only clinical feature of the epizootic. The accumulative mortality was as high as 30% (1, 500/5, 000). The characteristic bipolarity of bacilli in blood and squash smear of spleen were recognized. Lesions of white, circumscribed areas were scattered throughout the parenchyma of spleen and kidney. Histologically, the acute focal necrosis with various sizes of bacterial clumps were apparent. Based on the growth characters, morphological and biochemical properties of the isolated bacterium, it was classified into the genus Pasteurella. The isolate was sensitive to the most antimicrobial agents tested, and the epizootic was effectively controlled by the medication with chloramphenicol.The 50% lethal dose of Formosa snake-head fish to this Pasteurella isolate was 101.9 CFU/ml which indicates the bacterium is highly pathogenic to this particular fish species. The lesions similar to the natural cases were produced together with re-isolation of the inoculated bacterium from the experimentally infected fish.