Search PubMed⌕ Search

Biomedical subjects

Thomas V Colby

Publications and source records attributed to Thomas V Colby.

At least 19 recordsLinked to original sources
PubMed2003

Prognostic value of desaturation during a 6-minute walk test in idiopathic interstitial pneumonia.

Exercise-induced hypoxia is an index of the severity of interstitial lung disease. We hypothesized that desaturation during a 6-minute walk test would predict mortality for patients with usual interstitial pneumonia (n = 83) and nonspecific interstitial pneumonia (n = 22). Consecutive patients with biopsy-proven disease performed a 6-minute walk test between January 1996 and December 2001. Desaturation was defined as a fall in oxygen saturation to 88% or less during the 6-minute walk test. Desaturation was common (44 of 83 usual interstitial pneumonia and 8 of 22 nonspecific interstitial pneumonia; chi square, p = 0.39). Patients with usual interstitial pneumonia or nonspecific interstitial pneumonia who desaturated had a significantly higher mortality than patients who did not desaturate (respective log-rank tests, p = 0.0018, p = 0.0089). In patients with usual interstitial pneumonia, the presence of desaturation was associated with an increased hazard of death (hazard ratio, 4.2; 95% confidence interval, 1.40, 12.56; p = 0.01) after adjusting for age, sex, smoking, baseline diffusion capacity for carbon monoxide, FVC, and resting saturation. We conclude that knowledge of desaturation during a 6-minute walk test adds prognostic information for patients with usual interstitial pneumonia and nonspecific interstitial pneumonia.

Cohort Studies↗
PubMed2003

Clinical diagnosis of hypersensitivity pneumonitis.

The diagnosis of hypersensitivity pneumonitis (HP) is difficult and often relies on histopathology. Our objective was to identify diagnostic criteria and to develop a clinical prediction rule for this disease. Consecutive patients presenting a condition for which HP was considered in the differential diagnosis underwent a program of simple standardized diagnostic procedures. High-resolution computed tomography scan and bronchoalveolar lavage (BAL) defined the presence or absence of HP. Patients underwent surgical lung biopsy when the computed tomography scan, BAL, and other diagnostic procedures failed to yield a diagnosis. A cohort of 400 patients (116 with HP, 284 control subjects) provided data for the rule derivation. Six significant predictors of HP were identified: (1) exposure to a known offending antigen, (2) positive precipitating antibodies to the offending antigen, (3) recurrent episodes of symptoms, (4) inspiratory crackles on physical examination, (5) symptoms occurring 4 to 8 hours after exposure, (6) and weight loss. The area under the receiver operating characteristic curve was 0.93 (95% confidence interval: 0.90-0.95). The rule retained its accuracy when validated in a separate cohort of 261 patients. The diagnosis of HP can often be made or rejected with confidence, especially in areas of high or low prevalence, respectively, without BAL or biopsy.

Algorithms↗
PubMed2003

Fibrotic idiopathic interstitial pneumonia: the prognostic value of longitudinal functional trends.

Survival is linked to the histopathologic distinction between usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP), the most commonly encountered fibrotic idiopathic interstitial pneumonia. We retrospectively compared the prognostic significance of histopathologic diagnoses, baseline pulmonary function indices, and serial trends in pulmonary function indices (diffusing capacity, FVC, FEV1, the recently defined composite physiologic index) at 6 and 12 months in 104 patients (UIP, n = 63; fibrotic NSIP, n = 41). Survival was lower in UIP than in fibrotic NSIP (p = 0.001) but not in patients with severe functional impairment; mortality during the first 2 years was linked solely to the severity of functional impairment at presentation. The composite physiologic index was the strongest determinant of outcome (p < 0.001). At 6 months, serial diffusing capacity levels (p = 0.003) and histopathologic diagnosis (p = 0.002) were prognostically equivalent. At 12 months, serial pulmonary function trends were the only major prognostic determinant (p < 0.0005 for all variables), with no independent significance associated with the distinction between UIP and fibrotic NSIP. We conclude that at 12 months, serial pulmonary function trends have considerable prognostic value in UIP and NSIP. Their histologic distinction provides no additional prognostic information when pulmonary function trends are clear cut or when functional impairment is severe.

Aged↗
PubMed2003

Prognostic implications of physiologic and radiographic changes in idiopathic interstitial pneumonia.

Idiopathic interstitial pneumonias are a diverse group of lung diseases with varied prognoses. We hypothesized that changes in physiologic and radiographic parameters would predict survival. We retrospectively examined 80 patients with usual interstitial pneumonia and 29 patients with nonspecific interstitial pneumonia. Baseline characteristics were examined together with 6-month change in forced vital capacity, diffusing capacity for carbon monoxide, and ground glass infiltrate and fibrosis on high resolution computed tomography. Patients with usual interstitial pneumonia were more likely to have a statistically significant or marginally significant decline in lung volume, diffusing capacity for carbon monoxide, and an increase in ground glass infiltrates (p < or = 0.08) compared with patients with nonspecific interstitial pneumonia. For patients with usual interstitial pneumonia, change in forced vital capacity was the best physiologic predictor of mortality (p = 0.05). In a multivariate Cox proportional hazards model controlling for histopathologic diagnosis, gender, smoking history, baseline forced vital capacity, and 6-month change in forced vital capacity, a decrease in forced vital capacity remained an independent risk factor for mortality (decrease > 10%; hazard ratio 2.47; 95% confidence interval 1.29, 4.73; p = 0.006). We conclude that a 6-month change in forced vital capacity gives additional prognostic information to baseline features for patients with idiopathic interstitial pneumonia.

Adult↗
PubMed2003

Idiopathic pulmonary fibrosis: a composite physiologic index derived from disease extent observed by computed tomography.

In idiopathic pulmonary fibrosis, the quantitation of disease severity using pulmonary function tests is often confounded by emphysema. We have identified the composite physiologic index (CPI) most closely reflecting the morphologic extent of pulmonary fibrosis. Consecutive patients with a clinical/computed tomography (CT) diagnosis of idiopathic pulmonary fibrosis (n = 212) were divided into group I (n = 106) and group II (n = 106). The CPI was derived in group I (by fitting pulmonary function tests against disease extent on CT) and was tested in Group II. The formula for the CPI was as follows: extent of disease on CT = 91.0 - (0.65 x percent predicted diffusing capacity for carbon monoxide [DLCO]) - (0.53 x percent predicted FVC) + (0.34 x percent predicted FEV1). In group II, the CPI correlated more strongly with disease extent on CT (r2 = 0.51) than the individual pulmonary function test (DLCO the highest value, r2 = 0.38). A subanalysis demonstrated that the better fit of the CPI was ascribable to a correction of the confounding effects of emphysema. Mortality was predicted more accurately by the CPI than by a pulmonary function test in all clinical subgroups, including a separate cohort of 36 patients with histologically proven usual interstitial pneumonia (CPI, p < 0.0005; FVC, p = 0.002; PO2, p = 0.002). In conclusion, a new CPI, derived against CT and validated using split sample testing, is a more accurate prognostic determinant in usual interstitial pneumonia than an individual pulmonary function test.

Aged↗
PubMed2003

Fibroblastic foci in usual interstitial pneumonia: idiopathic versus collagen vascular disease.

A histologic feature of usual interstitial pneumonia is the presence of fibroblastic foci. As some patients with usual interstitial pneumonia and an underlying collagen vascular disease have a better prognosis, we hypothesized that they would have fewer fibroblastic foci. Pathologists reviewed surgical lung biopsies from 108 patients with usual interstitial pneumonia (nine with collagen vascular disease) and assigned a score (absent 0, mild 1, moderate 2, and marked 3) for fibroblastic foci. Patients with idiopathic usual interstitial pneumonia had a higher median profusion of fibroblastic foci (1.75 vs. 1.0, p = 0.003). Baseline characteristics were similar, although patients with a collagen vascular disease were younger, had a shorter duration of symptoms, and had a higher percentage of predicted total lung capacity. Profusion of fibroblastic foci was the most discriminative feature for separating idiopathic from collagen vascular disease-associated usual interstitial pneumonia (odds ratio 8.31; 95% confidence interval, 1.98, 59.42; p = 0.002 for a one-unit increase in fibroblastic foci score). No deaths were noted in the collagen vascular disease-associated usual interstitial pneumonia group; 52 deaths occurred in the idiopathic usual interstitial pneumonia group (log rank; p = 0.005). We conclude that patients with collagen vascular disease-associated usual interstitial pneumonia have fewer fibroblastic foci and improved survival.

Analysis of Variance↗
PubMed2003

Surgical pathology of granulomatous interstitial pneumonia.

Agranulomatous interstitial pneumonia is a form of diffuse lung disease in which granulomas are a component of the histologic findings. The differential diagnosis is quite broad, but most cases represent examples of either sarcoidosis, diffuse granulomatous infections, or hypersensitivity pneumonitis. "Hot tub lung" is a recently described form of granulomatous interstitial pneumonia that appears to have some features of diffuse infections and some features of hypersensitivity pneumonitis. The pathologist's approach to these conditions can be facilitated by giving careful attention to the anatomic distribution of the granulomas, the qualitative features of the granulomas, and the histologic changes in the lung tissue around and away from the granulomas. These features, along with the results of cultures and special stains for micro-organisms and clinical and radiologic correlation allow for a diagnosis in the vast majority of cases.

Diagnosis, Differential↗
PubMed2003

Noninfectious lung pathology in patients with Crohn's disease.

Lung involvement in Crohn's disease is not well characterized. We reviewed our experience with 11 lung biopsies (seven wedge and four transbronchial) from patients with Crohn's disease to study this association further. Negative cultures, special stains for organisms Gomori-methenamine-silver [GMS], acid fast), and polymerase chain reaction for (four cases) were required for inclusion. The group included five women and six men with a mean age of 47 years (range 13-84 years). A diagnosis of Crohn's disease preceded the lung disease in nine patients. In two patients the diagnosis of Crohn's disease followed the diagnosis of their pulmonary disease 1 and 15 months later. Radiologically, eight patients had diffuse infiltrates, two had bilateral nodular infiltrates, and one had a mass. Chronic bronchiolitis with nonnecrotizing granulomatous inflammation was present in four patients, one of whom was taking mesalamine. Two patients had an acute bronchiolitis associated with a neutrophil-rich bronchopneumonia with suppuration and vague granulomatous features. One patient on mesalamine had cellular interstitial pneumonia with rare giant cells. Four patients demonstrated organizing pneumonia with focal granulomatous features, two of whom were taking mesalamine, and one of these two responded to infliximab (anti-tumor necrosis factor) monoclonal antibody therapy. Noninfectious pulmonary disease in patients with Crohn's disease has variable histologic appearances, including granulomatous inflammation and airway-centered disease resembling that seen in patients with ulcerative colitis. Drugs may contribute to pulmonary disease in some patients.

Adult↗
PubMed2003

Encapsulated versus nonencapsulated superficial fatty masses: a proposed MR imaging classification.

OBJECTIVE: The purpose of this study was to assess the MR imaging appearance of palpable fatty masses and to propose terminology for palpable subcutaneous fatty masses that are nonencapsulated on MR imaging. MATERIALS AND METHODS: We searched the past 7 years of our institution's radiology database for reports of MR images containing the word "lipoma." Medical records were reviewed to identify patients with palpable masses corresponding to fat. Two radiologists retrospectively reviewed the MR images for the presence of an encapsulated or nonencapsulated fatty mass in the region of the palpable abnormality. Pathologic specimens, when available, were also reviewed. RESULTS: Between 1995 and 2001, 184 palpable subcutaneous fatty masses were evaluated on MR imaging. Of these, 46% (85/184) were encapsulated lipomas and 54% (99/184) were nonencapsulated fatty masses on MR imaging. Four masses (three encapsulated and one nonencapsulated) were surgically resected and had pathology consistent with lipomas. CONCLUSION: Many palpable fatty masses do not have definable capsules on MR imaging. We propose that a palpable mass that corresponds to a nonencapsulated prominence of subcutaneous fat on MR imaging should be reported as a nonencapsulated lipoma. More definitive reporting of this relatively common lesion will assure the referring clinician of the benign nature.

Adipose Tissue↗
PubMed2003

Pulmonary sclerosing hemangioma with lymph node metastases: report of 4 cases.

CONTEXT: Sclerosing hemangioma is an unusual pulmonary tumor. Previously, 4 patients with pulmonary sclerosing hemangioma and lymph node metastases have been described in the literature. OBJECTIVE: To report 4 additional cases of metastatic sclerosing hemangioma. DESIGN: Retrospective review of the authors' consultation files and review of histologic sections of pulmonary tumors and lymph node metastases. RESULTS: Four cases of a morphologically benign pulmonary sclerosing hemangioma with regional lymph node metastases (including hilar, peribronchial, and interlobar metastases) were identified. The patients (3 female, 1 male) had a mean age of 39 years (range, 10-56 years). The tumors ranged in size (greatest dimension) from 1.5 to 4.7 cm (mean, 3.1 cm). The pulmonary tumors were typical circumscribed sclerosing hemangiomas without mitotic activity, angiolymphatic invasion, or necrosis. One tumor had focal cytologic atypia. The metastases were identified in hilar lymph nodes that were removed at operation for the lung nodule. One patient received adjuvant chemotherapy for adenocarcinoma. All of the patients are alive. No recurrences or residual disease has been detected at a mean follow-up of 4.7 years (range, 2.3-10 years). CONCLUSIONS: On the basis of case data from the 4 patients described here and the 4 patients described previously, metastases to regional lymph nodes from pulmonary sclerosing hemangioma may occur but are rare and do not appear to affect prognosis.

Adolescent↗
PubMed2002

Pathologic review of the Mayo Lung Project cancers [corrected]. Is there a case for misdiagnosis or overdiagnosis of lung carcinoma in the screened group?

BACKGROUND: In the Mayo Lung Project Screening Trial, there were more carcinomas identified in the screened group compared with the control group. The screened group had better survival, but there was no difference in lung carcinoma mortality between the screened group and the control group. The purpose of this study was to review all available original pathology from the trial to determine whether overdiagnosis (carcinomas that do not result in the death of the patient) or misdiagnosis of lung carcinoma may explain this discrepancy. METHODS: All available lung pathology slides from patients who underwent surgery at the Mayo Clinic were reviewed independently by three blinded lung pathologists. Tumors were classified according to the 1999 World Health Organization criteria. In addition, agreement among the pathologists was assessed. RESULTS: Among 106 patients who underwent surgery at the Mayo Clinic, slides were available for review from 105 patients, including 77 slides from the screened group and 28 slides from the control group. The original diagnosis of carcinoma was confirmed in all patients. In 7 patients (6.7%), there was unanimous agreement that the lesion was preinvasive (carcinoma in situ), and these lesions all were from the screened group. In 90 patients (85.5%), there was unanimous agreement that the tumors were invasive. In 8 patients (7.8%), there was some disagreement between the observers about whether lesions were invasive or preinvasive; 7 of these 8 lesions were from the screened group. The level of agreement among pathologists for invasive carcinomas was > 94% for all comparisons, and the kappa statistic ranged from 0.67 (substantial agreement) to 0.84 (almost perfect agreement). There was good agreement among the pathologists about tumor cell type with the kappa statistic >/= 0.65. CONCLUSIONS: The histologic diagnosis of carcinoma was confirmed for all 105 slides that were reviewed. The results of this study indicate that misdiagnosis does not explain the increased numbers of carcinomas identified in the screened group. The increased numbers of in situ carcinomas in the screened group resulted in increased numbers of squamous carcinomas in the screened group compared with the control group and may have contributed to the better survival. It is possible that carcinoma in situ accounted for some instances of overdiagnosis.

Carcinoma↗
PubMed2002

Recurrent lymphangiomyomatosis after transplantation: genetic analyses reveal a metastatic mechanism.

Lymphangiomyomatosis (LAM) is characterized by the proliferation of abnormal smooth muscle cells and cystic degeneration of the lung. LAM affects almost exclusively young women. Although lung transplantation provides effective therapy for end-stage LAM, there are reports of LAM recurrence after lung transplantation. Whether these recurrent LAM cells arise from the patient or the lung transplant donor is an area of controversy. We used microsatellite marker fingerprinting and TSC2 gene mutational analysis to study a patient with recurrent LAM after single-lung transplantation. The DNA microsatellite marker pattern indicated the presence of patient-derived LAM cells in the allograft. A somatic one base pair deletion in exon 18 of the TSC2 gene was identified in pulmonary and lymph node LAM cells before transplantation. The same mutation was in the recurrent LAM, demonstrating that the recurrent LAM was derived from the patient. Fluorescence in situ hybridization revealed that cells immunoreactive with the monoclonal antibody HMB-45 did not contain a Y chromosome. These data indicate that histologically benign LAM cells can migrate or metastasize in vivo to the transplanted lung. In addition, the patient had no evidence of a renal angiomyolipoma at autopsy and therefore demonstrated for the first time that somatic TSC2 mutations cause LAM in patients without angiomyolipomas.

Adult↗
PubMed2002

The relationship between individual histologic features and disease progression in idiopathic pulmonary fibrosis.

We have retrospectively studied 53 patients with idiopathic pulmonary fibrosis and a histologic diagnosis of usual interstitial pneumonia and evaluated the prognostic significance of four individual histologic features (fibroblastic foci [FF], interstitial mononuclear cell infiltrate, established fibrosis, and intra-alveolar macrophages) using a semiquantitative scale of 0-6. An objective count of FF was also undertaken. Using weighted kappa coefficients, interobserver agreement between pathologists was moderate to good (0.56-0.76). Subjective and objective FF scores were strongly associated (R(S) = 0.88, < 0.00005). Mortality was independently linked to a high FF score, p = 0.006, and a low percent predicted carbon monoxide diffusing capacity (DL(CO)), p = 0.01. For pulmonary function, on univariate analysis, the strongest correlations were observed between increasing interstitial mononuclear cell infiltrate or FF scores and greater declines in forced vital capacity (FVC) or DL(CO) at 6 months. Multivariate models revealed that increasing FF scores were independently associated with greater declines in FVC and DL(CO) at both 6 and 12 months. Increasing interstitial mononuclear cell infiltrate scores were also independently linked to functional decline, but only at 6 months. These data suggest a reproducible method on biopsy for predicting rate of disease progression in patients with idiopathic pulmonary fibrosis.

Biopsy↗
PubMed2002

Histopathologic subsets of fibrosing alveolitis in patients with systemic sclerosis and their relationship to outcome.

Fibrosing alveolitis associated with systemic sclerosis (FASSc) has a better prognosis than idiopathic pulmonary fibrosis. In view of recent reports that idiopathic nonspecific interstitial pneumonia (NSIP) has a better prognosis than idiopathic usual interstitial pneumonia (UIP), we classified histologic appearances of surgical lung biopsies performed in 80 patients with FASSc. NSIP (n = 62, 77.5%), subcategorized as cellular NSIP (n = 15) and fibrotic NSIP (n = 47) was much more prevalent than UIP (n = 6), end-stage lung disease (ESL, n = 6), or other patterns (n = 6). There were 25 deaths (NSIP 16/62, 26%; UIP/ESL 6/12, 50%). Five-year survival differed little between NSIP (91%) and UIP/ESL (82%); mortality was associated with lower initial carbon monoxide diffusing capacity (DL(CO)) and FVC levels (p = 0.004 and p = 0.007, respectively). Survival and serial FVC and DL(CO) trends did not differ between cellular and fibrotic NSIP. Increased mortality in NSIP was associated with lower initial DL(CO) levels (p = 0.04), higher BAL eosinophil levels (p = 0.03), and deterioration in DL(CO) levels during the next 3 years (p < 0.005). We conclude that NSIP is the histopathologic pattern in most patients with FASSc. However, outcome is linked more strongly to disease severity at presentation and serial DL(CO) trends than to histopathologic findings.

Adult↗
PubMed2002

Endometrial stromal sarcoma metastatic to the lung: a detailed analysis of 16 patients.

Pulmonary metastases of endometrial stromal sarcoma (ESS) are uncommon and can pose diagnostic problems. We reviewed lung specimens from 16 patients with metastatic ESS. Patients were 31-77 years of age at the time of lung biopsy. Uterine ESSs were diagnosed an average of 9.8 years before lung biopsy in 11 patients. Uterine ESSs were originally called smooth muscle tumors in three additional patients. Thirteen patients were evaluated for new pulmonary nodules, seven of whom were asymptomatic. Nodules were multiple in 14 and solitary in four, ranging from 1.0 to 8.0 cm in greatest dimension. One patient died of metastatic disease; 14 were alive and seven of these were without disease (mean follow-up 4.1 years). Diagnostic considerations in 12 consultation cases included ESS, sclerosing hemangioma, carcinoid tumor, lymphangioleiomyomatosis, endometriosis, hemangiopericytoma, and lymphoma. Tumors were well circumscribed and usually solid, composed of plump spindle cells arranged in short fascicles. Two tumors were predominantly cystic. Sex cord-like stromal differentiation was identified in three. Neoplastic cells stained for vimentin (93%), estrogen and progesterone receptor (100%), smooth muscle actin (57%), desmin (50%), and keratin (46%). Metastatic ESS should be included in the differential diagnosis of nonepithelial neoplasms in women.

Actins↗
PubMed2002

Small cell lung carcinoma (SCLC): a clinicopathologic study of 100 cases with surgical specimens.

Separation of small cell lung carcinoma (SCLC) from nonsmall cell lung carcinoma (NSCLC) is a critical distinction to be made in the diagnosis of lung cancer. However, the diagnosis of SCLC is most commonly made on small biopsies and cytologic specimens, and practicing pathologists may not be familiar with all its morphologic guises and frequent combination with NSCLC elements, which may be seen in larger specimens. Following the most recent WHO classification of lung tumors and with the hope of identifying prognostic markers, we examined in detail the histology of 100 surgical biopsies or resections with a diagnosis of SCLC from the AFIP and pathology panel of the International Association for the Study of Lung Cancer (IASLC). Multiple clinical and histologic features were studied by Kaplan-Meier analysis. Neuroendocrine architectural patterns, including nested and trabecular growth, with peripheral palisading and rosette formation were common in SCLC. Necrosis and apoptotic debris was prominent in all cases, but crush artifact was infrequent. Cell size in surgical biopsy specimens appears larger than in bronchoscopic biopsy specimens and occasional cells may show prominent nucleoli and vesicular nuclear chromatin, but this does not preclude the diagnosis of SCLC. A high percentage of cases (28%) showed combinations with NSCLC, with large cell carcinoma the most common, followed by adenocarcinoma and squamous cell carcinoma. Because of the frequency of a few scattered large cells in SCLC, we arbitrarily recommend that at least 10% of the tumor show large cell carcinoma before subclassification as combined SC/LC. However, combined SCLC is easily recognized if the additional component consists of other NSCLC subtypes such as adenocarcinoma or squamous cell carcinoma, so no percentage requirement is needed. Stage remained the only predictor of prognosis.

Adult↗