Concordance of PD-L1 expression and CD8+ TIL intensity between NSCLC and synchronous brain metastases.

Programmed death-ligand 1 (PD-L1) is suggested to be a predictive biomarker in non-small-cell lung carcinoma (NSCLC). However, the differential expression of PD-L1 in primary lung tumor vs. synchronous metastases, especially brain metastasis (BM), remains unclear. This study assessed the concordance of PD-L1 expression on tumor cells and tumor-infiltrating lymphocytes (TILs) and CD8+ TIL intensity between primary lung tumors and synchronous BMs from 24 NSCLC patients. PD-L1, CD3, and CD8 positivity was determined by immunohistochemistry (IHC). PD-L1 scoring was based on the proportion of tumor cells with membranous expression of PD-L1 and the cutoff values <1%, 1-49%, and ≥50%. CD3 and CD8 positivity in TILs was evaluated semi-quantitatively and the proportion of CD3+/CD8+ TILs was determined. PD-L1 expression on tumor cells and TILs was evaluated in relation to CD3+/CD8+ TIL proportions and the intensity of CD8+ TILs between the paired primary lung and BM tissues. In the primary lung tumors, PD-L1 positivity was observed in 25%, 37.5%, and 37.5% cases for the cutoff values <1%, 1-49%, and ≥50%, respectively. PD-L1 expression on tumor cells was strongly correlated between the paired primary lung and BM tissues, in all cutoff groups. However, PD-L1 expression on TILs and the proportion of CD3+/CD8+ TILs were not strongly correlated in all three groups between the paired primary lung tumors and BMs. The intensity of CD8+ TILs was concordant in only 54.16% of the paired primary lung tumors and BMs. This study showed a high concordance of PD-L1 expression in neoplastic cells between primary NSCLC and synchronous BMs.

Macroscopic complete resection is not associated with improved survival in patients with malignant pleural mesothelioma.

OBJECTIVE: Macroscopic complete resection (MCR) is the recommended surgical strategy in malignant pleural mesothelioma. Our objective was to analyze whether MCR influences survival in malignant pleural mesothelioma. METHODS: Between 2002 and 2016, 154 patients underwent pleurectomy decortication (n = 90), extrapleural pneumonectomy (n = 42), or exploratory/diagnostic procedures (n = 22) in a single institution. Patient data were recorded in a prospective database. Patients who underwent surgical resection (n = 132) were analyzed according to MCR as a whole group and after propensity score matching based on gender, age, histology, clinical T and N status, adjuvant chemotherapy, and trimodality treatment. Kaplan-Meier survival and univariate and multivariate analyses were performed. RESULTS: Median age was 56 years (range, 26 to 80 years) and 62 were women. One hundred ten had epithelioid histology. MCR was achieved in 75 patients (49%). In-hospital mortality was seen in 7 patients (4.5%). Preoperative chemotherapy was applied in 32 patients. One hundred thirty-three patients underwent adjuvant treatment (45 had chemoradiation). Mean follow-up was 21 ± 19 months. Overall median survival, 2-year, and 5-year survivals were 18.1 months, 36%, and 16%, respectively. There was no difference in median survival between patients who underwent MCR (21.4 months) and who did not (16.3 months) (P = .6). Following propensity score matching (23 patients in each group), median survivals were similar (13.3 vs 14.2 months; P = .63). CONCLUSIONS: MCR was not associated with improved survival in malignant pleural mesothelioma. We need to clearly define MCR and identify subgroups of patients who would benefit from this principle because minimal versus extensive and location of gross residual disease may have different influences on survival.

Extranodal pulmonary marginal zone B-cell lymphoma.

AIM: Extranodal mucosa-associated lymphoid tissue (MALT) arises a number of epithelial tissues, including the stomach, salivary gland, lung, small bowel, and elsewhere. Here we present a male patient with an uncommon site of extranodal MALT such as a pelvic mass diagnosed after a long period of evaluation, which initially presented with an incidental pulmonary nodule. METHOD: We report a 60 years old man presenting with pulmonary nodules and consolidation. He refused invasive procedures and 3 years later was administered to our clinic with disseminated pulmonary nodules on chest X-ray. Subsequently a thin needle aspiration biopsy was performed and candida geotrichum was suspected in the specimen of the lung biopsy by light microscopic examination. After this time the patient was referred to our clinic, bronchoscopy, mediastinoscopy and abdominal computerized tomography (CT) scans were performed. RESULTS: Lymphoid hyperplasia was seen in the mediastinal lymph nodes biopsy specimens and the pelvic mass (52 × 18 mm) on the superior iliac muscles not related to any organs. Thin needle biopsy revealed MALT lymphoma and pathological examination of pulmonary nodule was similar to pelvic mass (MALT lymphoma). After the diagnosis, the thin needle biopsy of lung was repeated. The specimen appeared to be similar to the pelvic mass (MALT lymphoma) in the pathologic examination. The patient survived 5 years after initial diagnosis. CONCLUSION: MALT has an affinity for the different tissues however has not been located in the pelvis. Our case represent an unusual presentation in a 60 years old man with lung and a pelvic mass.

Decreased sputum caveolin-1 is associated with systemic sclerosis related lung disease.

AIM: To determine serum and sputum Caveolin-1 (Cav-1) levels and their associations with transforming growth factor- ß (TGF-ß) and interstitial lung disease (ILD) in systemic sclerosis (SSc). METHODS: Serum and induced sputum samples from 55 patients with SSc, 25 asthma patients and 16 healthy volunteers (HC) were tested for Cav-1 and TGF-ß by the ELISA technique. As a possible downstream signaling regulator of TGF-ß, Endothelin-1 (ET-1), a potent profibrotic protein, was also measured in all serum and sputum samples and relations with Cav-1 and TGF-ß were sought. All scleroderma patients were evaluated for their clinical and laboratory parameters. Pulmonary function tests (PFT) and high resolution computerized tomography (HRCT) were performed for the diagnosis of ILD. The alveolitis-fibrosis index and the SSc disease severity scores were noted for each patient. RESULTS: Serum Cav-1 levels were lower in SSc compared to HC (p<0.01). Cav-1 levels were significantly lower in the sputum of SSc patients compared to both control groups (p<0.001). It was also found significantly lower in SSc-ILD compared to those without ILD (0.19±0.04 vs 0.25±0.07, respectively, p<0.01). Although no difference was found in the serum TGF-ß levels among the groups, sputum TGF-ß levels correlated positively with the alveolitis index (r=0.34) and correlated inversely with FVC measurements (r=-0.44, p<0.05) among SSc patients. Serum ET-1 was significantly higher in SSc patients (p<0.01) but no association was found between ET-1 and Cav-1 or TGF-ß. CONCLUSION: These results suggest that decreased sputum Cav-1 levels is associated with SSc related-ILD and may be used as a marker for the detection of SSc-ILD.

Interobserver agreement among histological patterns and diagnosis in lung adenocarcinomas.

OBJECTIVE: The aim of this study was to investigate the interobserver agreement in determination of the dominant histological pattern and the final diagnosis in lung adenocarcinomas. MATERIAL AND METHOD: A total of 12 patients with a diagnosis of primary lung adenocarcinoma were included in the study. Twelve pathologists from eight study centers were asked first to determine the dominant histological pattern in these cases and then to decide whether the final diagnosis was in situ, minimally invasive or invasive adenocarcinoma. RESULTS: The kappa value for the agreement in determining the dominant pattern among the pathologists was 0.36 (p < 0.001), with the values for the lepidic, acinar, papillary, solid, micropapillary patterns and mucinous character of adenocarcinoma being 0.34, 0.28, 0.30, 0.80, 0.16 and 0.38 respectively (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001). None of the cases was diagnosed as in situ adenocarcinoma. On the other hand, the kappa value for the agreement in differentiating minimally invasive from invasive adenocarcinoma among reviewers was 0.17 (p < 0.001). CONCLUSION: The agreement among pathologists in determining the subtype of lung adenocarcinomas that depends on the identification of the dominant pattern was at intermediate level. In addition, the agreement in deciding whether the case is minimally invasive or invasive, was at low level. The criteria defining the histological patterns should be clarified and described in more detail. Educational activities and larger multicenter studies might be helpful in improving the agreement and standardization.

Thyroid fine needle aspiration biopsy: do we really need an on-site cytopathologist?

PURPOSE: The aim of this single center study is to evaluate the effectiveness of performing ultrasound-guided thyroid fine-needle aspiration biopsies (FNAB) performed by the radiologist alone without an on-site cytopathologist. MATERIALS AND METHODS: In this prospective randomized study, 203 patients with single nodules measuring 10mm or more underwent ultrasound-guided FNAB: 102 patients underwent FNAB performed by the radiologist accompanied by a cytopathologist (control group); 101 patients underwent FNAB by the radiologist alone (study group). In both groups biopsy time, specimen adequacy ratio, total aspiration number, cytopathologist's cytological diagnosis time (t1), cytopathologist's total time consumption (t2) were evaluated. RESULTS: Mean total biopsy time was 8.74 ± 2.31 min in the study group and was significantly shorter than the control group's 11.97 ± 6.75 min (p=0.004). The average number of aspirations per patient in the study group was 4.00 ± 0; compared to the control group's 3.56 ± 1.23 this was significantly higher (p=0.001). t1 of the study group was 307.48 ± 226.32s; compared to 350.14 ± 247.64 s in the control group, there was no statistically significant difference (p=0.137). t2 of the study group was 672.93 ± 270.45 s; compared to the control group (707.03 ± 258.78 s) there was no statistically significant difference (p=0.360). Diagnostic adequacy of aspirated specimens was reassessed in the pathology laboratory. In the study group, 84 out of 101 aspirations and in the control group 89 out of 102 aspirations was determined as adequate with no statistically significant difference (p=0.302). CONCLUSIONS: We believe that in centers where a cytopathologist is not available, ultrasound-guided thyroid FNAB can be adequately performed by an experienced radiologist who was effectively trained in smear preparation.

The value of ultrasound elastography in differentiation of malignancy in thyroid nodules.

We aimed to determine the value of ultrasound elastography (US-E) using carotid artery pulsation in differentiation of malignant and benign thyroid nodules. One hundred ten nodules were evaluated by US-E, and stiffness scores were compared to biopsy results. When cutoff for malignancy was determined as score 4, sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 95%, 40%, and 100%, respectively. We suggest fine needle aspiration biopsy to be performed in all score 4 nodules, while biopsy may be unnecessary in score 1 nodules. Benign biopsy result in a score 4 nodule should suggest radiological-pathological disagreement, and repeat biopsy should be recommended.

Prevalence of HPV infection by cytologic diagnosis and HPV DNA extraction and prevalence of the HPV genotypes detected in urban Turkish women.

OBJECTIVE: To evaluate the prevalence of the different human papillomavirus (HPV) genotypes in women seen at 2 Marmara University Hospital gynecologic outpatient clinics in Istanbul, Turkey. METHODS: From May 1 through August 31, 2008, specimens were obtained from 500 women for cytologic evaluation by the split-sample method. HPV types were identified by PCR and hybridization using a microarray that identifies 35 types. RESULTS: The overall prevalence of HPV was 16.5%, multiple genotypes were found in 35.8% of the infected women, and 75% of the types were high risk; 79% of the infected women had negative cytologic results, 3.7% had ASCUS, 10% had LSIL, and 6% had HSIL; the highest infection rates were 36% for women aged 20 to 30 years and 35% for those aged 31 to 40 years; 65.2% of the infected women were university graduates; and 34% were single. CONCLUSION: HPV infection involved numerous types, most of them high risk, even in women with negative cytology results. Further studies with larger groups will provide more information on HPV distribution in Turkey, which may guide the development of local vaccination programs.

Biodegradable microspherical implants containing teicoplanin for the treatment of methicillin-resistant Staphylococcus aureus osteomyelitis.

BACKGROUND: The aim of this study was to prepare poly(d,l-lactide-co-glycolide) (PLGA) microspherical implants containing teicoplanin (TCP) using a double emulsion solvent evaporation method and to evaluate its efficacy for the local treatment of chronic osteomyelitis. METHODS: The particle size and distribution, morphological characteristics, thermal behaviour, drug content, encapsulation efficiency and in vitro release assessments of the formulations were carried out. Sterile TCP­PLGA microspheres were implanted in the proximal tibia of rats with methicillin resistant Staphylococcus aureus (MRSA) osteomyelitis. After 3 weeks of treatment, bone samples were analysed with a microbiological assay and evaluated histopathologically. RESULTS: Microspheres between the size ranges of 2.01 and 3.91 µm were obtained. Production yield of all formulations was found to be higher than 82% and encapsulation efficiencies of 33.6­69.8% were obtained. DSC thermogram showed that the TCP was in an amorphous state in microspheres. In vitro drug release studies had indicated that the drug release rate of microspheres was decreased upon increasing the polymer:drug ratio. Based on the in vivo data, rats treated with implants and intramuscular injection showed 1.7 × 10(3) ± 1.3 × 10(3) and 5.8 × 10(4) ± 5.3 × 10(4) colony forming unit of MRSA in 1 g bone samples (CFU/g), respectively (P < 0.01). CONCLUSIONS: The in vitro and in vivo studies had shown that the TCP­PLGA microspheres were effective for the treatment of chronic osteomyelitis in an animal experimental model. Hence, these microspheres may be potentially useful in the clinical setting with the need for further investigation for optimal dosing of TCP­PLGA microspheres.

Epithelioid hemangioendothelioma with multiple organ involvement.

Epithelioid hemangioendothelioma is a rare vascular neoplasm of uncertain malignant potential. Various reports document metastatic or concurrent epithelioid hemangioendothelioma in several sites, most commonly with combined lung and liver involvement. The concurrent involvement of multiple sites at presentation may cause diagnostic problems because epithelioid hemangioendothelioma can mimic other neoplastic processes. Although it is a chemo-resistant disease, chemotherapy is usually advised for patients with metastatic or concurrent involvement. Here we document the presentation, treatment, and outcome of two cases with concurrent involvement of the lung and liver.

Sodium fusidate-poly(D,L-lactide-co-glycolide) microspheres: preparation, characterisation and in vivo evaluation of their effectiveness in the treatment of chronic osteomyelitis.

PURPOSE: The aim of this study was to prepare poly(D,L-lactide-co-glycolide) (PLGA) microspheres containing sodium fusidate (SF) using a double emulsion solvent evaporation method with varying polymer:drug ratios (1:1, 2.5:1, 5:1) and to evaluate its efficiency for the local treatment of chronic osteomyelitis. METHODS: The particle size and distribution, morphological characteristics, thermal behaviour, drug content, encapsulation efficiency and in vitro release assessments of the formulations had been carried out. Sterilized SF-PLGA microspheres were implanted in the proximal tibia of rats with methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis. After 3 weeks of treatment, bone samples were analysed with a microbiological assay. RESULTS: PLGA microspheres between the size ranges of 2.16-4.12 microm were obtained. Production yield of all formulations was found to be higher than 79% and encapsulation efficiencies of 19.8-34.3% were obtained. DSC thermogram showed that the SF was in an amorphous state in the microspheres and the glass transition temperature (T(g)) of PLGA was not influenced by the preparation procedure. In vitro drug release studies had indicated that these microspheres had significant burst release and their drug release rates were decreased upon increasing the polymer:drug ratio (p < 0.05). Based on the in vivo data, rats implanted with SF-PLGA microspheres and empty microspheres showed 1987 +/- 1196 and 55526 +/- 49086 colony forming unit of MRSA in 1 g bone samples (CFU/g), respectively (p < 0.01). CONCLUSION: The in vitro and in vivo studies had shown that the implanted SF loaded microspheres were found to be effective for the treatment of chronic osteomyelitis in an animal experimental model. Hence, these microspheres may be potentially useful in the clinical setting.

Solitary fibrous tumor of the kidney. Case report.

Solitary fibrous tumors are rare spindle cell neoplasms usually arising in the pleura. They have, however, also been reported at extrapleural locations. Solitary fibrous tumor (SFT) of the kidney is rare. Despite its rarity, histological diagnosis of solitary fibrous tumor is crucial to avoid misdiagnosis with other more aggressive tumors arising in the kidney. We report a solitary fibrous tumor of the left kidney that presented as a malignant tumor in a 51-year-old woman, and include clinical and radiographic findings. The tumor was well circumscribed and composed of spindle cells in a collagenous stroma. Immunohistochemistry showed reactivity for vimentin, CD 34, BCL-2 protein and CD99. Immunohistochemical stains for cytokeratin, S-100, desmin, alpha-smooth muscle actin and HMB-45 were negative. A diagnosis of SFT was made based on light microscopy and immunohistochemistry.

Safety of a thermal vessel sealer on main pulmonary vessels.

OBJECTIVE: LigaSure (Valleylab, Tyco Healthcare, Boulder, CO) is a novel instrument with widespread use in various surgical disciplines for vessel sealing. It uses heat energy to denature collagen and elastin and achieve vessel sealing. We investigated the safety of LigaSure in pulmonary arteries (PA) and veins (PV). METHODS: Twelve sheep were anesthetized and endotracheally intubated. Six underwent right lower lobectomy (Group 1) and six right upper lobectomy (Group 2). All of the vessels in both groups were divided with LigaSure. Diameters of vessels were measured. Intraoperatively, pulmonary artery pressures (PAP) were monitored in Group 1. Following vascular division, ephedrine was injected to increase PAP in Group 1. In Group 2, animals were followed and euthanized at 7 days. Both immediate and 7 day samples were obtained from divided vessel stumps. Conventional histology was done. Statistical analysis was performed using t-test and Fisher's exact test. RESULTS: Mean diameter of PAs (n=9) divided in Group 1 was 8.3mm (3-11) and of PVs (n=8) was 10.4mm (4-15). Mean PAP increased from 18 (27/9) to 27 (45/18)mmHg after ephedrine injection. Dehiscence rate was 2/6 in PAs and 3/6 in PVs larger than 9 mm in diameter. Mean diameter of PAs (n=8) divided in Group 2 was 5.7 mm (3-7) and of PVs (n=9) was 4.6mm (4-6). No early or late (7 days) vascular disruption was seen in Group 2. Bleeding incidence was significantly different between groups (Fisher's exact test p=0.015). Overall no dehiscence was observed in vessels less than 7 mm in diameter. Histology of intraoperative samples showed thermal injury and necrosis. Seven day samples showed short segment necrosis limited to the vessel wall, fibrosis, thrombus formation without inflammation, and minimal granulation tissue. CONCLUSIONS: LigaSure achieves perfect sealing in pulmonary vessels less than 7 mm in diameter in sheep intra- and postoperatively even following a pressure challenge. It can safely be used in segmental branches of PAs and PVs during open or thoracoscopic surgery.

Acute exacerbation of interstitial fibrosis after pulmonary resection.

Idiopathic pulmonary fibrosis is a chronic diffuse lung disease of unknown cause, and a risk factor for increasing morbidity and mortality after lung resection. Acute exacerbation of idiopathic pulmonary fibrosis after lung surgery for lung cancer is rare. The outcome is unsatisfactory despite therapy. We report two cases of acute exacerbation of idiopathic pulmonary fibrosis after resection for lung cancer.

Effects of multiple pulmonary aspirations of enteral solutions on lung tissue damage.

BACKGROUND & AIM: The aim of this study was to compare the pulmonary histopathologic effects of enteral solutions with various lipid content, after multiple aspirations in rats. METHODS: Thirty Wistar albino rats were randomly assigned to one of three groups (n = 10). Saline solution (0.9%) (group C, control), Impact (lipid content, 28 g/l; group I), Pulmocare (lipid content, 93.3g/l; group P) were injected into the lung through the trachea, in a volume of 0.8 ml/kg. The aspiration procedure was performed three times in total, in every 2 days. After seven days from the first aspiration, rats were killed, and lungs were examined for histopathologic examination. RESULTS: Alveolar histiocytes were statistically higher in left lungs of the group I than the left ones of the control group (P < 0.05). Lipid-laden alveolar macrophages were significantly higher in left lungs of groups I and, P than left lungs of the control group (P<0.05). CONCLUSION: Lung tissue damage occurring after multiple pulmonary aspirations of Impact and Pulmocare, is histopathologically similar to each other, and is in the form of lipoid pneumonia. In cases of multiple pulmonary aspirations, volume of the aspirate and chronicity of the aspiration look like major impact factors rather than the amount of the lipid.

Results of paclitaxel (day 1 and 8) and carboplatin given on every three weeks in advanced (stage III-IV) non-small cell lung cancer.

BACKGROUND: Both paclitaxel (P) and carboplatin (C) have significant activity in non-small cell lung cancer (NSCLC). The weekly administration of P is active, dose intense, and has a favorable toxicity profile. We retrospectively reviewed the data of 51 consecutive patients receiving C and day 1 and 8 P chemotherapy (CT) regimen in advanced stage NSCLC to evaluate the efficacy and toxicity. METHODS: Patients treated in our institutions having pathologically proven NSCLC, no CNS metastases, adequate organ function and performance status (PS) ECOG 0-2 were given P 112.5 mg/m2 intravenously (IV) over 1 hour on day 1 and 8, followed by C AUC 5 IV over 1 hour, repeated in every three weeks. PC was given for maximum of 6 cycles. RESULTS: Median age was 58 (age range 39-77) and 41 patients (80%) were male. PS was 0/1/2 in 29/17/5 patients and stage was IIIA/IIIB/IV in 3/14/34 patients respectively. The median number of cycles administered was 3 (1-6). Seven patients (14%) did not complete the first 3 cycles either due to death, progression, grade 3 hypersensitivity reactions to P or lost to follow up. Best evaluable response was partial response (PR) in 45% and stable disease (SD) in 18%. Twelve patients (24%) received local RT. Thirteen patients (25%) received 2nd line CT at progression. At a median follow-up of 7 months (range, 1-20), 25 (49%) patients died and 35 patients (69%) progressed. Median overall survival (OS) was 11 +/- 2 months (95% CI; 6 to 16), 1-year OS ratio was 44%. Median time to progression (TTP) was 6 +/- 1 months (95% CI; 4 to 8), 1-year progression free survival (PFS) ratio was 20%. We observed following grade 3 toxicities: asthenia (10%), neuropathy (4%), anorexia (4%), anemia (4%), hypersensitivity to P (2%), nausea/vomiting (2%), diarrhea (2%) and neutropenia (2%). Two patients (4%) died of febrile neutropenia. Doses of CT were reduced or delayed in 12 patients (24%). CONCLUSIONS: P on day 1 and 8 and C every three weeks is practical and fairly well tolerated outpatient regimen. This regimen seems to be comparably active to regimens given once in every three weeks.

An unusual tumor of the spermatic cord: myositis ossificans.

OBJECTIVES: Tumors of the spermatic cord and epididymis are rare, and their exact incidence is difficult to determine. Ninety percent of extra testicular tumors within the scrotum are found in the spermatic cord, where 30% is malignant (1). METHODS: In this case report we present an unusual spermatic cord tumor, i.e. myositis ossificans (MO). To the best of our knowledge, MO of the spermatic cord has not been reported before in the literature. CONCLUSIONS: MO should be considered in the differential diagnosis of the spermatic cord tumors.

Extraorbital sebaceous carcinoma with rapidly developing visceral metastases.

BACKGROUND: Extraorbital sebaceous carcinoma (SC) is a rare carcinoma of the skin but is known to have a good prognosis in terms of metastasis and survival. OBJECTIVE: To discuss and emphasize through the clinical and histopathologic findings and the aggressive potential of extraorbital SC and to review the corresponding literature. METHODS: We present an unusual form of extraorbital SC that has followed an aggressive course and that has metastasized rapidly. RESULTS: Local excision of the primary cutaneous tumor with negative margins did not prevent the rapid and fatal internal organ metastases. The patient did not benefit from the docetaxel chemotherapy regimen applied after the distant metastases were developed. CONCLUSION: Extraorbital SC may show a poor prognosis. Both the dermatologic surgeon and the dermatologist should be cautious of the risk of local recurrence and distant metastasis when dealing with extraorbital SC.

Histopathologic effects of lipid content of enteral solutions after pulmonary aspiration in rats.

OBJECTIVE: We compared the pulmonary histopathologic effects of different enteral formulas with various lipid contents during the subacute period of aspiration in rats. METHODS: Fifty Wistar albino rats, weighing 180 to 300 g, were randomly assigned to one of five groups (n = 10). Anesthesia was induced with an intraperitoneal injection of 100 mg/kg of ketamine hydrochloride, rats were intubated endotracheally with a 16-gauge angiocatheter, and 0.9% saline (group 1, control), Impact (group 2), Jevity (group 3), Biosorb Energy Plus (group 4), or Pulmocare (group 5) with a lipid content of 0, 28, 39.3, 58, or 93.3 g/L, respectively, was injected into the lungs in a volume of 3 mL/kg. Seven days later, rats were killed, and lungs with trachea were removed en bloc for histopathologic examination. For histopathologic assessment, slides were examined for the presence of peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar histiocytes, interstitial fibrosis, granuloma, and necrosis formation. The degree of severity was assessed by using a 4-point scale. One-way analysis of variance and Student-Newman-Keuls test were used for statistical analysis. RESULTS: Peribronchial inflammatory cell infiltration was present in all groups but was significantly more severe in group 2 than in groups 1, 4, and 5 (P < 0.05). Alveolar edema was statistically higher in group 2 than in group 1 (P < 0.05). Alveolar septal infiltration was statistically higher in group 4 than in group 1. Alveolar histiocytes were statistically higher in groups 2 and 3 (P < 0.01) and groups 4 and 5 (P < 0.05) than in group 1. Alveolar exudate, interstitial fibrosis, granuloma, and necrosis formation were absent in all groups. CONCLUSION: The pulmonary histopathologic effects of aspiration of Impact were severe peribronchial inflammatory cell infiltration (greater than aspiration of Biosorb and Pulmocare), abundant alveolar histiocytes, and alveolar edema in comparison with aspiration of saline, even though Impact had the lowest lipid content of all studied formulas. We concluded that the tissue damage occurring after pulmonary aspiration of Impact is more severe than after aspiration of Pulmocare.