Buccal epithelium Expanded and Encapsulated in Scaffold-Hybrid Approach to Urethral Stricture (BEES-HAUS) procedure: A novel cell therapy-based pilot study.

OBJECTIVES: To describe the feasibility of a novel cell-based endoscopic technique using buccal epithelium, expanded and encapsulated in a thermoreversible gelation polymer scaffold for the treatment of urethral stricture. METHODS: Six male patients with bulbar urethral stricture ranging from 2.0 to 3.5 cm in length were included in this pilot study. Autologous buccal epithelial cells from a small buccal mucosal biopsy were isolated, cultured and encapsulated in thermoreversible gelation polymer scaffold, and were implanted at the stricture site after a wide endoscopic urethrotomy. RESULTS: All the patients voided well, with a mean peak flow rate of 24 mL/s. Urethroscopy carried out at 6 months showed healthy mucosa at the urethrotomy site. However, two of the six patients had recurrence at 18 and 24 months, respectively. CONCLUSIONS: This endoscopic-based Buccal epithelium Expanded and Encapsulated in Scaffold-Hybrid Approach to Urethral Stricture (BEES-HAUS) technique is a promising alternative for the open substitution buccal graft urethroplasty. It is possible to achieve the benefits of open substitution buccal urethroplasty with this endoscopic technique.

The effect of combined pulsed wave low-level laser therapy and mesenchymal stem cell-conditioned medium on the healing of an infected wound with methicillin-resistant Staphylococcal aureus in diabetic rats.

This study aims to investigate the combined effects of Pulsed wave low-level laser therapy (PW LLLT) and human bone marrow mesenchymal stem cell-conditioned medium (hBM-MSC-CM) on the microbial flora and tensiometrical properties of an infected wound model with methicillin-resistant staphylococcal aureus (MRSA) in an experimental model for Type 1 diabetes mellitus (TIDM). TIDM was induced in rats by streptozotocin (STZ). One full-thickness excision was made on the backs of the rats. Next, the rats were divided into the following groups: Group 1 was the control (placebo) group; Group 2 received hBM-MSCs-CM four times; Group 3 were laser PWLLLT (890 nm, 80 Hz, 0.2 J/cm2 ); and Group 4 received hBM-MSCs-CM +LASER. Wounds were infected with MRSA. Microbiological examinations were performed on days 4, 7, and 15. Tensiometerical examinations were carried out on the 15th day. One-way analysis of variance showed that laser and CM alone and/or in combination significantly increases the tensiomerical properties of the repaired wounds compared with control wounds. A combination of PW laser and CM was statistically more effective than other treated groups. Two-way analysis of variance showed that laser and CM alone and/or in combination significantly decreases the colony-forming units (CFUs) compared with the control group. The application of hBM-MSC-CM and PWlaser alone and/or together significantly accelerates the wound-healing process in MRSA-infected cutaneous wounds in TI DM in rats. Additionally, a combined application of hBM-MSC-CM and PWlaser demonstrates a synergistic effect on the wound-healing process in MRSA-infected cutaneous wounds in Type I DM rats.

Mycosis Fungoides, Then and Now Have We Travelled?

Mycosis fungoides (MF) is the most common type of cutaneous lymphoma, accounting for almost 50% of all primary cutaneous lymphomas. When initially described, it was believed to be a distinct clinical entity with a pathognomonic histopathologic picture. Through the years we have come to know that, like syphilis, MF is a great masquerader and can present clinically and histopathologically in many ways. This review is an attempt to cover the many faces of MF that have evolved through the years.

Neutrophilic Fixed Drug Eruption.

Fixed drug eruption (FDE) is a cutaneous reaction to a medication that recurs in the same fairly localized site with each exposure to the offending drug. The classical histopathologic findings in FDE consist of an interface dermatitis with predominantly lymphocytic inflammatory cell infiltrate. An unusual case of FDE in a 27-year-old pregnant woman who presented with widespread lesions and a predominantly neutrophilic infiltrate on histopathologic examination is reported.

Benign Endobronchial Tumors: A Clinicopathologic Review.

Purpose: Benign endobronchial tumors are rare entities that can be difficult to diagnose because they often present with non-specific symptoms and vague radiographic findings. The current study reviews the clinical, radiologic and pathologic features, diagnosis, and treatment of patients with benign endobronchial tumors. Methods: We examined the charts of all patients who presented with biopsy-proven benign endobronchial tumors at a tertiary-care academic medical center between 1993 and 2018. Pertinent clinicopathologic and radiologic data were analyzed, with particular attention paid to treatment modalities and mean overall patient survival. Results: A total of 28 cases were identified. The most common benign neoplasm was hamartoma (37%), followed by lipoma (19%), squamous papilloma (11%), pleomorphic adenoma (7%), mucin gland adenoma (7%), papillary adenoma (3%), hemangioma (3%), neurofibroma (3%), leiomyoma (3%), and papillomatosis (3%). Cough (58%), shortness of breath (44%), and hemoptysis (15%) were the most frequent presentations. Most cases demonstrated well-defined submucosal or pedunculated endobronchial lesions with segmental pneumonia or atelectasis on imaging. Histologic diagnosis was obtained by endobronchial resection in 43% of patients, thoracoscopic lobectomy in 36%, endobronchial biopsy in 18%, and thoracoscopic wedge resections in 3%. All procedures were performed with no intraoperative or in-hospital deaths (mean overall survival: 20.2 years). Conclusion: Benign endobronchial tumors typically present as well-defined submucosal and/or pedunculated lesions, and may lead to post-obstructive complications. Endobronchial resection is the preferred strategy for diagnosis and treatment of these tumors.

Correlation of p16 Expression on Cancer and Stromal Cells With Clinicopathologic and Immunohistochemical Features of Lobular Breast Carcinoma.

BACKGROUND: Cancer-associated fibroblasts, play a central role in the tumor-stroma interaction and promote tumorigenesis. However, it is still unclear how these processes are regulated. The aim of this study is to investigate p16 expression in cancer and stromal cells of invasive lobular carcinoma (ILC). DESIGN: Clinicopathologic parameters and immunohistochemical stains for estrogen receptor (ER), progesterone receptor, E-cadherin, and human epidermal growth factor receptor 2 of 70 ILC cases were retrieved. In addition, immunohistochemical were performed for p53, p16, and cyclin D1. The p16 expression in cancer and stromal cells were correlated with different clinicopathologic parameters. RESULTS: Of the 70 cases, 8 cases were p16- cancer and stromal cells, 14 cases p16- cancer and p16+ stromal cells, 14 cases p16+ cancer and p16- stromal cells, and 34 cases p16+ cancer and stromal cells. Thirty-one of the 59 cases showed axillary lymph node metastases. Nodal involvement, recurrence, and metastasis of ILC with p16+ cancer cells and p16- stromal cells were more frequent compared with other groups. ILC with p16+ cancer and p16- stromal cells were frequently negative for ER, progesterone receptor, and cyclin D1, p53 positive and triple negative compared with other groups. There was no recurrence and metastasis in ILC with p16- cancer and p16+ stromal cells. ILC with p16+ cancer and stromal cells were significantly node negative and were positive for ER and cyclin D1 compared with other groups. CONCLUSIONS: ILC with p16+ cancer and p16- stromal cells were characterized by frequent nodal involvement, recurrence, and metastatic propensity. These results suggest that p16, has novel anticancer properties capable of suppressing cancer cell migration and invasion and pharmacologic restoration of p16 level in stromal fibroblasts may be exploited as therapeutic strategy to prevent nodal or distant metastasis.

The effect of combined photobiomodulation and curcumin on skin wound healing in type I diabetes in rats.

The purpose of the present scientific study was to analyze the effects of combined pulsed wave Photobiomodulation (PW PBM) and Curcumin on the microbial flora; in addition, the tensiometrical wounds properties for type one diabetes mellitus (TIDM) in an experimental animal model. TIDM induction was performed in thirty rats. In the entire animals, one full-thickness excision was implemented on their backs. Randomly, the divisions of rats into 5 groups took place. The primary group was considered as the control group and did not receive any treatment. The secondary group (placebo) received sesame oil by gastric gavage. The third group received PWPBM (890 nm, 80 Hz, 0.2 J/cm2). The fourth group received curcumin (40 mg/kg, which was dissolved in sesame oil) by gastric gavage. Eventually, the fifth group received PW PBM + curcumin. Precisely, on day 7, microbiological examinations, and on the 15th day microbiological and tensiometrical examinations were conducted. The data were analyzed by statistical tests. PW PBM, significantly exacerbated tensiometrical properties of the TIDM repairing wound. PW PBM, curcumin, and PWPBM + curcumin significantly decreased colony forming units compared to the control and the placebo groups indeed. It was remarkably attained that PW PBM significantly accelerated the process of wound healing in the STZ-induced TIDM. The PW PBM was statistically more compelling compared to the curcumin and PWPBM + curcumin. PW PBM, curcumin, and PWPBM + curcumin significantly decreased colony forming units compared to the control and placebo groups.

Fenofibrate-Induced Lichenoid Drug Eruption: A Rare Culprit.

A lichenoid drug eruption is a rare side effect which can occur following the administration of several different medications. Here we describe a unique case of fenofibrate as the causative agent of a lichenoid drug eruption. This case highlights a rare and clinically significant dermatologic side effect of fenofibrate. In addition, we report a potential familial association which underscores the potential for underlying genetic mechanisms to be contributory to lichenoid drug eruptions. A reminder of the physical characteristics of lichen planus, knowledge of the temporal relation between administration of medications and a lichenoid drug eruption, recognition of the effect of UV exposure on lichenoid drug eruptions, and realization for the potential of symptoms to persist despite discontinuation of an offending agent can aid practitioners in promptly diagnosing lichenoid drug eruptions and initiating appropriate therapy.

Cytomorphology and Clinicopathologic Correlation of the Recurrent and Metastatic Adult Granulosa Cell Tumor of the Ovary: A Retrospective Review.

Granulosa cell tumors (GCT) of the ovary are low grade tumor with a potential ability of late pelvic recurrences and distant metastases. However, there is sparse literature on the cytopathologic features of metastatic granulosa cell tumors (MGCT). Between 2000 and 2014, eight cases of MGCT were diagnosed by FNA. Clinical, cytologic, and histopathologic features were reviewed. The age ranged from 34 to 84 years. Metastases were found in abdominal wall (4 cases), pelvic mass (1 case), liver (2 cases), and lung (1 case). The time to metastasis ranged from 1 to 14 years. All cases were hypercellular, with both large and small overlapping cell clusters and individual cells. The cytologic features included: naked nuclei (8/8 cases), Call-Exner bodies (2/8 cases), and prominent metachromatic stroma (3/8 cases). Moderate cytoplasm (4/8 cases) to scant delicate cytoplasm (4/8 cases) was seen. Cytoplasmic vacuoles were also noted (6/8 cases). N/C ratios were high although lower than small round cell tumors like lymphoma. Prominent, central nucleoli were also present (6/8 cases) as well as nuclear grooves (2/8 cases). Cell block was available in 3/8 cases and all were positive for inhibin immunostain. Histologic examination of the metastatic tissue confirmed MGCT. The important cytologic features of GCT like uniformity of tumor cells, nuclear grooves and Call-Exner bodies are occasionally present in MGCT. Prominent nucleoli and many naked nuclei were frequent. Therefore, the accurate interpretation of cytologic findings of MGCT requires cytohistologic correlation and inhibin positivity to avoid unnecessary surgical interventions for diagnostic purposes. The possibility of late recurrence of GCT should be kept in mind. Diagn. Cytopathol. 2016;44:1058-1063. © 2016 Wiley Periodicals, Inc.

Cytomorphology, clinicopathologic, and cytogenetics correlation of myelomatous effusion of serous cavities: A retrospective review.

BACKGROUND: Myelomatous effusions (ME) of the serous cavities are rare. Identification of the atypical plasma cells in the body fluids may be critical for prognostic considerations. METHODS: We retrospectively reviewed clinicopathologic findings of 21 serous effusion specimens from 13 cases of ME including 10 pleural, two concurrent pleural and pericardial, and one peritoneal from 1994 to 2014. RESULT: All 13 patients had bone marrow biopsy-proven plasma cell myeloma (PCM), including one plasmablastic-variant, one anaplastic-variant and one plasma cell leukemia. The time between the bone marrow diagnoses to serous cavity involvement ranged from 43 days to 9 years (mean 2.6 years, median 1.8 years). Monoclonal protein types showed predominant IgA subtypes (50%) including IgA-kappa (2), IgA-lambda (3), IgG-kappa (2), IgG-lambda (1) free kappa chain (1) and free lambda chain (1) and three unknown. All 13 patients died of disease (median survival 32 days). Concurrent imaging studies showed evidence of adjacent local disease. Cytology of the serous fluids revealed abundant plasma cells with varying degrees of atypia, including large cells with increased N/Cratios, coarse chromatin, and prominent nucleoli. All were CD138 positive. Of these, Cytology confirmed malignancy in 19/21(90%) cases. Five cases were positive for kappa-light chain and eight cases for lambda-light chain. Cytogenetics of 3/7 cases showed normal karyotype and 4/7 cases showed complex-karyotype. The patients with kappa light-chain had better survival compared to lambda light-chain (p = 0.051, log rank test). CONCLUSION: ME in PCM can present early in the natural history of the disease or very late. The preponderance of IgA-myeloma and complex-cytogenetics abnormalities is a noteworthy finding. Although there are different hypotheses regarding how ME develops in PCM, our finding supports the hypothesis that direct spread of PCM into serous cavities is a likely mechanism. Diagn. Cytopathol. 2016;44:742-747. © 2016 Wiley Periodicals, Inc.

Prognostic Value of Coexisting Lobular Carcinoma In Situ With Invasive Lobular Carcinoma.

AIMS AND OBJECTIVES: Recent studies show that lobular carcinoma in situ (LCIS) and invasive lobular carcinoma (ILC) share similar genetic molecular biology. There are increasing concerns regarding the biological significance of LCIS. The aim of this study is to investigate whether the presence of coexisting LCIS in ILC affects tumor biology and behavior and to correlate it with other clinicopathologic parameters. MATERIALS AND METHODS: In this study, 254 cases of ILC were included. Clinicopathologic parameters and immunohistochemical stains for estrogen receptor (ER), progesterone receptor (PR), E-cadherin, human epidermal growth factor receptor (HER2), and MIB-1 of 254 ILC cases were retrieved. The patient with ILC and coexisting LCIS were compared with pure ILC cases with respect to different clinicopathologic parameters. RESULTS: Of the 254 cases, 107 cases were pure ILC and 147 cases were ILC with coexisting LCIS. Seventy-six (76/184, 41.32%) cases showed axillary lymph node metastases. Lymph node metastasis was absent in 108 cases, micrometastasis was present in 5 cases, and stage N1, N2, N3 in 51, 5, and 15 cases, respectively. Nodal involvement, locoregional and distant recurrence of ILC with LCIS were less frequent compared with ILC without LCIS with P-value of 0.034 and 0.007, respectively. The presence of coexisting LCIS in ILC predicted higher disease-free survival (DFS) compared with pure ILC (P=0.034, log-rank test). When divided into different strata, ER-positive ILC cases with associated LCIS cases showed better DFS than ER-positive pure ILC cases (P=0.021, log-rank test). Similarly, ILC cases with LCIS in patient less than 50 years showed better DFS than the patient less than 50 years with pure ILC (P=0.045, log-rank test). CONCLUSIONS: In conclusion, ILC coexisting with lobular carcinoma in situ (ILC+LCIS) is characterized by less nodal involvement, lower locoregional, and distant recurrence and better DFS than pure ILC. When divided into different strata, ER-positive and less than 50-year groups with ILC+LCIS show even significant better DFS than pure ILC. These findings suggest that there is biological significance of coexisting LCIS in ILC and that this may have more effect on tumor aggressiveness in certain strata of ILC.

Computational chemical imaging for cardiovascular pathology: chemical microscopic imaging accurately determines cardiac transplant rejection.

Rejection is a common problem after cardiac transplants leading to significant number of adverse events and deaths, particularly in the first year of transplantation. The gold standard to identify rejection is endomyocardial biopsy. This technique is complex, cumbersome and requires a lot of expertise in the correct interpretation of stained biopsy sections. Traditional histopathology cannot be used actively or quickly during cardiac interventions or surgery. Our objective was to develop a stain-less approach using an emerging technology, Fourier transform infrared (FT-IR) spectroscopic imaging to identify different components of cardiac tissue by their chemical and molecular basis aided by computer recognition, rather than by visual examination using optical microscopy. We studied this technique in assessment of cardiac transplant rejection to evaluate efficacy in an example of complex cardiovascular pathology. We recorded data from human cardiac transplant patients' biopsies, used a Bayesian classification protocol and developed a visualization scheme to observe chemical differences without the need of stains or human supervision. Using receiver operating characteristic curves, we observed probabilities of detection greater than 95% for four out of five histological classes at 10% probability of false alarm at the cellular level while correctly identifying samples with the hallmarks of the immune response in all cases. The efficacy of manual examination can be significantly increased by observing the inherent biochemical changes in tissues, which enables us to achieve greater diagnostic confidence in an automated, label-free manner. We developed a computational pathology system that gives high contrast images and seems superior to traditional staining procedures. This study is a prelude to the development of real time in situ imaging systems, which can assist interventionists and surgeons actively during procedures.

Myocardial changes in a patient with anorexia nervosa: a case report and review of literature.

OBJECTIVES: Anorexia nervosa (AN) is an eating disorder with high mortality and morbidity. Much of the mortality is related to cardiovascular complications manifesting with electrocardiogram abnormalities and morphologic abnormalities documented on ultrasound. However, gross and histologic abnormalities in the heart have been rarely described in association with this eating disorder. METHODS: We present an autopsy case of an adult patient with AN. We describe the clinical presentation of this patient, as well as significant gross and histologic abnormalities of the heart, and discuss their implications. RESULTS: At autopsy, the heart was small with mainly a small left ventricle. Histologically, we found endocardial and interstitial fibrosis, areas of myxoid material deposition with mast cells in the background, and increased cytoplasmic lipofuscin. CONCLUSIONS: The gross findings in the heart correlate with the previously described anomalies on cardiac ultrasound of patients with AN. The fibrosis and myxoid material deposition might be a direct consequence of starvation and the mechanism of death in some patients with AN.

Assessment of Her-2/Neu status by immunohistochemistry and fluorescence in situ hybridization in mammary Paget disease and underlying carcinoma.

HER-2/Neu overexpression is seen in 20% to 30% of invasive breast carcinomas and has been reported in as many as 80% of high-grade infiltrating carcinomas. Earlier studies have suggested that 100% of the tumor cells in mammary Paget disease show overexpression of HER-2 protein. We undertook this study to assess HER-2 status of mammary Paget disease and of the underlying breast carcinoma, when present, by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Formalin-fixed, paraffin-embedded tissue from 20 cases of mammary Paget disease were analyzed for HER-2 status by IHC and FISH. IHC for estrogen receptor (ER) was also performed. The patients ranged in age from 34 to 88 years, with a mean age of 62 years. Eighty percent of the cases showed strong overexpression (3+) of HER-2 protein by IHC, and all of these cases showed more than 5-fold amplification of the HER-2 gene by FISH. The remaining 4 cases, which were negative for HER-2/Neu by IHC, showed no amplification by FISH. All of the latter cases expressed ER, whereas no case that overexpressed HER-2 expressed ER. Sixteen cases had an underlying tumor, which was in situ in 6 cases. The underlying tumors were identical to the Paget disease with respect to their HER-2/Neu overexpression by both IHC and FISH. HER-2 overexpression was identified in 80% of our cases of Paget disease. There was 100% concordance between HER-2 protein overexpression by immunohistochemistry and gene amplification in both the Paget and the underlying tumor. Moreover, all of the cases negative for HER-2 overexpression expressed ER, whereas those positive for HER-2 did not.

Fine-needle aspiration of clinically suspicious palpable breast masses with histopathologic correlation.

BACKGROUND: The purpose of this study was to compare the diagnostic accuracy of fine-needle aspiration (FNA) of clinically suspicious palpable breast masses in women younger and older than 40 years of age. METHODS: All women who had FNA biopsy with subsequent tissue biopsy were included. The cytologic diagnoses were classified into three groups: malignant, suspicious, or benign. Histopathologic correlation was based on either a needle core biopsy, an excisional biopsy, or a mastectomy specimen. RESULTS: A total of 1,158 fine-needle aspirations performed between 1982 and 2000, on women being evaluated for a clinically palpable breast mass were included in the study. The patients were divided into two groups: group I consisted of 231 patients aged 40 years and younger, and group II consisted of 927 patients aged 41 years and older. In group I there were 117 (51%) malignant FNA diagnoses, and only 1 (1%) false-positive case, subsequently diagnosed on histopathologic material as an atypical papillomatosis. There were 20 (9%) cases diagnosed as suspicious on FNA. On histopathology 10 were malignant, and 10 were benign. Of the 91 (39%) cases interpreted as benign, only 1 (1%) was a false negative. In group II, which comprised 927 patients, there were 693 (74%) malignant FNA diagnoses, and 3 (less than 1%) false-positive cases, which on follow-up histopathologic examination revealed 2 atypical ductal hyperplasias and 1 atypical papilloma. There were 90 (10%) cases diagnosed as suspicious on FNA. On histopathology, 68 were malignant and 22 were benign. Of the 131 (14%) lesions interpreted as benign, there were 18 false-negative cases (14%), which included 17 infiltrating carcinomas and 1 ductal carcinoma in-situ. Twelve (1%) of the cases were inadequate for the study. CONCLUSIONS: The sensitivity, specificity, and positive predictive values were remarkably high and comparable in both groups: group I had 99% sensitivity, 99% positive predictive value, 99% specificity, and 99% negative predictive value; and group II had 98% sensitivity, 97% specificity, 99% positive predictive value, and 86% negative predictive value. The overall rate of false-positive (less than 1%) and false-negative cases (9%) is comparable with published literature. Suspicious cases should be further evaluated, as our study revealed more than 50% to be malignant. The incidence of malignancy in patients presenting with a clinically palpable breast mass with follow-up biopsy was 51% in patients aged 40 years and younger and 74% in patients aged 41 years and older. Fine-needle aspiration is an excellent diagnostic tool in assessing clinically palpable breast masses.

Cytologic-histologic correlations in the diagnosis of inverted sinonasal papilloma.

We present cytologic data from multiple samples from two cases of inverted sinonasal papilloma (ISP). These samples displayed the entire spectrum of squamous cell changes, including benign squamous papilloma, variable degrees of dysplasia, and invasive squamous cell carcinoma. In all instances, the cytologic impression coincided with the final diagnosis based on frozen and/or permanent histologic sections from the same samples. We suggest that cytologic examination be viewed as a useful initial approach in the diagnosis of ISP, and in the differential diagnosis of other tumors that occur in the same sites.

Fine-needle aspiration of subcutaneous panniculitis-like T-cell lymphoma.

We report the fine-needle aspiration (FNA) cytology findings of Subcutaneous Panniculitis-like T-cell Lymphoma (SCPTCL) in a 66-year-old woman who presented with a four month history of asymptomatic subcutaneous nodules on her right chest wall and back. An excisional biopsy of the right chest nodules was performed, and the diagnosis of SCPTCL was rendered. On a follow-up visit, several skin lesions were noted throughout her body. A fine-needle aspiration (FNA) of the right inguinal region was performed. The FNA yielded cellular smears, composed mainly of sheets of epithelioid histiocytes and scattered multinucleated cells. However, no distinct granulomas were noted. The background of the cytological smears showed scattered atypical lymphoid cells, some of which displayed nuclear membrane irregularities. To the best of our knowledge, the cytological features on FNA material of SCPTCL have not been described.

Anaplastic T large cell lymphoma diagnosed by exfoliative cytology in a post renal transplant patient.

In the last two decades posttransplant lymphoproliferative disorders (PTLDs) have been recognized as a complication of organ transplantation with immunosuppression. The reported incidence of PTLDs in renal transplant patients ranges between 0.3-3% (Birkeland et al., Transplantation 1999;67:876-881). In contrast to the reported incidence of PTLDs in post bone marrow transplant, it is 1% in HLA-matched recipients and up to 20% in HLA mismatched T-cell depleted bone marrow recipients (Curtis et al., Blood 1996;94:2208-2216). In cardiac transplant recipients the reported incidence of PTLDs is between 1.8-9.8 (Mihalov et al., Clin Transplant 1996;10:248-255). PTLDs are predominately extranodal. They have varied morphologic patterns and clonality, but almost all are associated with Epstein-Barr virus (EBV). The vast majority are of B cell lineage; only about 10% are of T-cell origin. We report a T-cell anaplastic large cell lymphoma (ALCL) presenting with bilateral pleural effusion and liver involvement in a renal transplant recipient.

Application of adjunct techniques in cytologic material in the diagnosis of rhabdomyosarcoma: case report and review of the literature.

A 4(1/2)-yr-old female presented with right-sided pleural effusion and a retroperitoneal mass. Cytologic analysis of the pleural fluid yielded malignant small round blue cells, which were noncohesive, 3-4 times the size of lymphocytes. The malignant cells had hyperchromatic, pleomorphic nuclei with moderate amounts of vacuolated cytoplasm. A few fiber-shaped cells were also seen. Immunostains for desmin, muscle-specific actin were positive; ultrastructural findings of thick and thin actin-myosin filaments confirmed the diagnosis of embryonal rhabdomyosarcoma. This case illustrates the importance of performing appropriate immunohistochemical stains and ultrastructural studies on cytological material to arrive at a definitive diagnosis.