Bone Marrow Metastases In Patients Research Articles

Prediction of Bone Marrow Metastases Using Computed Tomography (CT) Radiomics in Patients with Gastric Cancer: Uncovering Invisible Metastases

We investigated whether radiomics of computed tomography (CT) image data enables the differentiation of bone metastases not visible on CT from unaffected bone, using pathologically confirmed bone metastasis as the reference standard, in patients with gastric cancer. In this retrospective study, 96 patients (mean age, 58.4 ± 13.3 years; range, 28–85 years) with pathologically confirmed bone metastasis in iliac bones were included. The dataset was categorized into three feature sets: (1) mean and standard deviation values of attenuation in the region of interest (ROI), (2) radiomic features extracted from the same ROI, and (3) combined features of (1) and (2). Five machine learning models were developed and evaluated using these feature sets, and their predictive performance was assessed. The predictive performance of the best-performing model in the test set (based on the area under the curve [AUC] value) was validated in the external validation group. A Random Forest classifier applied to the combined radiomics and attenuation dataset achieved the highest performance in predicting bone marrow metastasis in patients with gastric cancer (AUC, 0.96), outperforming models using only radiomics or attenuation datasets. Even in the pathology-positive CT-negative group, the model demonstrated the best performance (AUC, 0.93). The model’s performance was validated both internally and with an external validation cohort, consistently demonstrating excellent predictive accuracy. Radiomic features derived from CT images can serve as effective imaging biomarkers for predicting bone marrow metastasis in patients with gastric cancer. These findings indicate promising potential for their clinical utility in diagnosing and predicting bone marrow metastasis through routine evaluation of abdominopelvic CT images during follow-up.

Abstract 5518: Tumor immune microenvironment of bone marrow metastasis in patients with solid tumor

Abstract Background: The tumor immune microenvironment plays a crucial role in tumor progression and treatment outcomes, both at the primary tumor site and metastatic sites. Metastatic growth within the bone marrow (BM) is relatively infrequent. Despite its unique immunological characteristics, there is a paucity of research on tumor immune microenvironment in the context of BM metastasis, particularly in patients with solid cancer. This study aims to elucidate the dominant immune cell populations within the BM of patients with solid cancer BM metastasis. Materials and Methods: Patients with solid tumors, who underwent BM examinations (aspiration and/or biopsy) for suspected BM metastasis at our institution between 2016 and 2023 were extracted from the database of pathology. To evaluate BM immune microenvironment in patients with BM metastasis originating from solid tumor, we performed flow cytometry analysis of myeloid and lymphoid subsets using bone marrow aspiration. Myeloid-derived suppressor cells (MDSCs) were defined as CD33+CD14+HLA-DR-/low. Additionally, a control group was established, consisting of patients in whom BM metastasis were pathologically ruled out. Results: The study involved the BM examinations in 39 patients, 22 of whom were pathologically diagnosed with BM metastasis. No substantial difference in age or gender were observed between patients with or without BM metastasis. However, the incidence of bone metastasis was significantly higher in the BM metastasis group compared to the non-BM metastasis group (90.9 vs. 47.1%, P=0.004). The median duration from the initial diagnosis of metastatic state to the occurrence of BM metastasis was 14.5 days (range 0 - 2194 days) for patients with BM metastasis, whereas it was 170 days (range 0 - 1304 days) for those without BM metastasis. Among the patients who underwent BM examinations, flow cytometry analysis was available in 13 patients with BM metastasis and 11 patients without BM metastasis. Our analysis revealed that a substantial increase in the mean percentage of MDSCs (CD14+HLA-DR-/low) in CD14+ monocytes of BM aspirates from patients with BM metastasis compared to those without (28.06 vs. 8.09%, P=0.0005). Additionally, while not statistically significant, the mean percentage of CD3+ T cells in the total live cell population appeared to be higher in patients with BM metastasis compared to those without (10.26 vs. 6.67%, P=0.0622). In terms of lymphoid subsets, CD4/8 ratio was significantly elevated in patients with BM metastasis as opposed to those without BM metastasis (1.57 vs. 0.76%, P=0.0472). Conclusion: The tumor immune microenvironment in BM metastasis was skewed toward immunosuppressive state. Further investigations are warranted to understand the involvement of other immune cells that also suppress immune system, such as regulatory T cells and M2 macrophages. Citation Format: Asaki Saijo, Keiichi Kinowaki, Kazumasa Yamamoto, Shogo Watanabe, Kohji Takemura, Takeshi Yamaguchi, Yuko Tanabe, Koichi Suyama, Hiromu Yano, Yoshihiro Komohara, Yuji Miura. Tumor immune microenvironment of bone marrow metastasis in patients with solid tumor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5518.

10143-COT-16 DIFFUSE BONE MARROW METASTASIS OF HIGH GRADE GLIOMA

Abstract BACKGROUND Extraneural metastasis of the high grade glioma has rarely been reported and its diffuse bone marrow metastasis is extremely rare. Case description: A 32-year-old man was referred and admitted to Shiga University of Medical Science Hospital for the treatment for three remote recurrent lesions in the brain after the treatment of the primary brain tumor in the right frontal lobe in the referring hospital. One of those lesions was subtotally resected, with histological and immunohistochemical analysis showing a grade 4 glioma, and stereotactic radiation therapy was performed at all three lesions. A lumbar spine MRI showed signal changes in the first and 4th vertebral bodies and the level of LDH was gradually increased during this hospitalization. Three months later, the patient was referred to our hospital again because of intractable lumbago with metastatic lesions in the lumbar vertebrae and the psoae major. Laboratory data showed pancytopenia and extremely elevated level of LDH-1 and LDH-2, suggesting aggressive hemolysis. Abdominopelvic CT also showed slight osteolytic changes in the ilia, sacra, and femurs. Biopsy of the psoas major and iliac bone marrow showed invasion of grade 4 glioma cells. The patient was diagnosed as having diffuse bone marrow metastasis of grade 4 glioma, and died 12 days after the second admission. CONCLUSIONS We have presented a rare case of diffuse bone marrow metastasis of high grade glioma. LDH elevation might mean hemolysis by bone marrow metastasis in patients with high grade glioma.

FDG-PET/CT Demonstrates Splenic Angiosarcoma Bone Marrow Metastasis.

Some patients with splenic angiosarcoma initially manifest thrombocytopenia owing to hypersplenism or tumor-related bone marrow fibrosis. The diagnosis of bone marrow metastasis in patients with splenic angiosarcoma is challenging, as the presentation mimics idiopathic thrombocytopenic purpura or primary myelofibrosis. Our case showed diffuse FDG uptake in the vertebral bodies, sacroiliac bone, humerus, femur, and clavicles. It was pathologically diagnosed as bone marrow metastasis of splenic angiosarcoma. We believe that the heterogeneous FDG accumulation in the bone marrow, although nonspecific, can be useful for the diagnosis of the bone marrow metastasis in patients with splenic angiosarcoma.

Gastric Cancer Patients with Bone Marrow Metastasis: A Single-Center Experience and Review of the Literature

Objectives: The purpose of this study is to investigate bone marrow metastasis in patients with Gastric cancer. Methods: We retrospectively evaluated patients with gastric cancer who applied to our clinic between 2010-2016. Results: 896 patients with gastric cancer were included in the study. Patients had metastatic bone marrow in 8 patients. When the laboratory results were evaluated; in 5 patients trombocytopenia with anemia were present, 2 patients had only tromboscytopenia, one patient had only anemia. In all patients white blood cell count was within normal range. The median survival of the 8 patients in our study was 72 days. In our chemoteraphy group (6 patients) median survival was 77 days (range, 49 to 145 days), in the non-treatment group was 7,5 days (range, 3 to 12 days). Conclusion: Gastric cancer with bone marrow metastasis is usually seen in younger patients, and is related to poorly differantiated subtypes and is a disease with worse prognosis. Median survival with paliative chemotraphy is under 3 months.

Predictive Value of Clinical and Laboratory Parameters for Overt Bone Marrow Metastasis in Patients with Solid Malignancy

Bone marrow (BM) metastases are known to worsen the outcome in patients with malignancies and alter the choice of the treatment regimen. In an attempt to identify routine parameters for the prediction of BM metastasis we evaluated the clinical and laboratory data of 103 patients with metastatic solid tumors. We also assessed which of these factors appeared to influence survival. Three laboratory abnormalities were found to be predictive of metastasis on BM biopsy: thrombocytopenia < 50 × 109/L OR 14.4; p = 0.02; hypocellular or dry tap aspirate OR 7.0; p = 0.02 and high serum alkaline phosphatase OR 6.5; p = 0.03. Three additional factors were found to be associated with deceased survival. Thrombocytopenia was associated with decreased survival from a median of 0.8 months to 4.1 months, p < 0.0001. Serum LDH levels more than twice the upper limit of normal were also reduced survival from 1.8 months versus 4.7 months, p = 0.03. Finally, the initial diagnosis of malignancy by bone marrow examination was associated with reduced survival from 1.8 months vs. 4.0 months, p = 0.03 in individuals where BM metastases were not the presenting feature of malignancies. Use of these simple clinical parameters may help in the early diagnosis of bone marrow metastases and improve clinical approach.

CT imaging of bone and bone marrow infiltration in malignant melanoma—Challenges and limitations for clinical staging in comparison to 18FDG-PET/CT

Rationale of this study was the evaluation of the diagnostic value of computed tomography (CT) in the detection of bone marrow infiltration in comparison to PET/CT.Fifty patients (age 61±15.12years) with metastatic malignant melanoma underwent 18F-FDG-PET/CT, including contrast-enhanced CT. 2 readers evaluated the CT images in consensus for bone and bone marrow lesions focusing on lesion location, type and size. PET/CT was used as reference standard to estimate sensitivity, specificity, negative and positive predictive value. Moreover, the bone marrow density was estimated in the long bones and the sacral bone. Serum hamoglobin, thrombocyte level and S100 protein were correlated with the presence or absence of bone and bone marrow lesions.According to PET/CT as standard of reference, of 594 bone and medullary lesions 495 were considered malignant. Of these 77.8% were medullary, 20.4% lytic, 1% sclerotic and 0.8% mixed lytic/sclerotic. Contrast-enhanced CT yielded a lesion-based sensitivity of 36.8% and a specificity of 87.9% (PPV 93.8%; NPV 21.8%). Patient-based sensitivity and specificity were 78.8% and 82.4%, respectively. Of the missed lesions, most were medullary (95.8%). A disseminated bone marrow involvement (defined as >10 bone marrow lesions or diffuse infiltration of a whole body segment) was described in 11 cases, in 6 cases the disseminated involvement was underestimated or missed on CT. In cases with disseminated bone marrow involvement the bone marrow density was significantly higher in the humerus (p=0.04), but not in the femur or sacral bone (p=0.06). Multivariate analysis revealed no isolated effect of bone metastases on S100 serum and hemoglobin level, but both were significantly altered in patients with disseminated bone marrow involvement (p<0.05).In conclusion, the diagnostic value of computed tomography for the detection of bone marrow metastases in patients with melanoma, is limited. Especially in cases with disseminated bone marrow involvement about 50% of the cases were missed or underestimated.

Squamous cell carcinoma of buccal mucosa metastasizing to bone marrow: a case report and review of the literature

Bone marrow metastasis in patients with oral squamous cell carcinoma is a very rare phenomenon. A 38-year-old male patient presented with carcinoma of the buccal mucosa postoperatively. The histopathological diagnosis was that of a moderately differentiated squamous cell carcinoma. Biochemical, fine-needle aspiration findings, and PET scan suggested distant spread. The bone marrow showed involvement by squamous cell carcinoma, which was confirmed immunohistochemically. Clinical, biochemical, hematological, and radiological findings are essential for detecting early bone marrow metastasis in head and neck cancer patients, especially squamous cell carcinoma, and timely detection of bone marrow infiltration prevents unwarranted radical surgery.

Development and validation of a prognostic score to predict the survival in adult patients with solid tumors and bone marrow metastases.

e17730 Background: Bone marrow metastases in patients with solid cancers represent an advanced and dismal malignant disease. There are limited reports regard their clinical features and outcomes. W...

The prognostic significance of bone marrow metastases: evaluation of 58 cases.

Bone marrow biopsy is widely used method for diagnosis, follow-up and staging of hemato-oncologic diseases. This procedure is also used for determining the bone marrow metastasis in patients with solid tumors. In this study, clinical, hematological, and pathological features of 58 patients with bone marrow metastases diagnosed by bone marrow biopsies were examined retrospectively Among 3345 bone marrow biopsies performed in our hospital between January 2006 and August 2013, 58 cases with solid tumor metastasized to bone marrow were included in this study. Among 58 cases with solid organ carcinoma metastasis in bone marrow, mean age was 59.9. Thirty-nine cases were found to have a known primary tumor focus. The most common tumors metastasized to bone marrow were breast carcinomas (23 patients, 59%), gastric carcinomas (6 patients, 15.3%), prostate carcinomas (4 patients, 10,2%), and lung carcinomas (3 patients, 7.7%), respectively. Nineteen patients were firstly diagnosed from bone marrow biopsies as metastatic carcinomas. The median overall survival after bone marrow metastasis was 28 days (95% confidence interval: 7.5-48.4). The median overall survival difference was not statistically significant between patients with primary known and unknown tumor (P = 0.973). Statistically significant difference was observed between the survival of breast cancer and gastric cancer (P = 0.028). The most common hematologic symptom was the coexistence of anemia and thrombocytopenia (31%), thrombocytopenia (27.6%) and anemia (20.7%) alone. The median overall survival difference was statistically significant between patients who have anemia and thrombocytopenia (P < 0.005). Bone marrow biopsy is an easily accessible, easily applied, a useful procedure for diagnosing metastatic diseases in patients with hematologic symptoms such as anemia and thrombocytopenia besides being an uncomfortable procedure for patients. Furthermore, it is useful in predicting the prognosis and short survey after diagnosing bone marrow metastasis.

Predictive value of clinical and laboratory findings for overt bone marrow metastasis in patients with solid tumor.

e19529 Background: Bone marrow (BM) involvement is not a rare finding in advanced stages of solid tumors, it may have a profound influence on prognosis and affect a treatment approach. Methods: 103 patients (pts) with an advanced metastatic solid tumor were included in retrospective study. BM metastasis were diagnosed in 72 cases according to Bone marrow biopsy (BMB) ; 31 other metastatic pts. didn't have a marrow spread. We analyzed a basic demographic characteristics, localization of primary tumors and metastasis, laboratory tests, blood smears, BM aspirates (BMA) and biopsies reports.Results: Pts in both groups had comparable median age, gender distribution, pattern of primary tumor and metastatic spread. Hematological parameters' strong correlated with marrow metastasis were: anemia 83% vs. 61% p=0.015 ,thrombocytopenia 55% vs.16% p&lt;0.001 with higher MPV p=0.01, hypocellular/ dry tap marrow aspirate 58% vs.14% p=0.001 and leukoerythroblastic blood smear 82% vs.0% p&lt;0.0001. Leukoerythroblastosis(LEB) in 92% reflected hypocellular aspirate was not included in final analysis because of low rate recorder blood smears. Analysis of biochemical finding showed higher increase by 2 upper limits (&gt;2ULN) of LDH and ALP in the metastatic BM cohort: 50% vs. 16% and 35% vs. 9%, p=0.002 and p=0.007 respectively. Factors predicted metastatic BM by multivariate analysis were: thrombocytopenia &lt;50x109/L OR 14.4 95%CI (1.6-128), hypocellular BMA OR 7.0 95%CI (1.82-21.2) and alkaline phosphatase &gt;2ULN levels OR 6.5 95%CI ( 1.2-35.3). Causes which influenced the survival of pts with BM metastasis: thrombocytopenia &lt; 50X109/ L median survival 0.8 month 95% CI (0.1-1.5) vs. 4.1m 95%CI( 2.0-6.1), LDH level &gt;2ULN 1.8m 95%CI(0.5-3.0) vs.4.7m 95%CI(3.0-6.3) and tumor presenting with BM metastasis vs. previously recognized carcinoma with BM involvement 1.8m 95% CI(0.3-3.0) vs.4.0 m.95%CI(1.3-6.7).Conclusions: Our study demonstrated that thrombocytopenia , alkaline phosphatase level&gt;2ULN and probably LEB reflect hypoplastic BM predict BM metastasis in cancer patients; furthermore, thrombocytopenia, LDH&gt;2ULN and BM metastasis in a clinical presentation affect their survival.

Isolation of disseminated neuroblastoma cells from bone marrow aspirates for pretreatment risk assessment by array comparative genomic hybridization

In neuroblastoma, tumor biopsies are used for prognostic evaluation and risk assessment by molecular genetic analyses such as fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (array CGH). Analysis of primary tumors by array CGH can be hampered by the lack of sufficient tumor cells due to small biopsy size or availability of invaded bone marrow only. Given the importance of accurate assessment of genetic alterations in the diagnostic work-up of patients with neuroblastoma, we evaluated the possibility to analyze bone marrow metastases in patients with disseminated disease. Disseminated neuroblastoma cells were isolated from bone marrow aspirates by using either laser capture microdissection (LCM) or magnetic activated cell sorting (MACS). The array CGH profiles of these isolated metastases were compared to array CGH profiles and/or FISH data of the corresponding primary tumor. Here, we show that the major recurrent DNA copy number alterations detected in primary neuroblastoma tumors (i.e., 1p, 3p and 11q deletion, 17q gain and MYCN amplification) can be detected, with high sensitivity and specificity, in the disseminated neuroblastoma cells isolated from the bone marrow aspirates, using an array platform with high coverage for these regions. Moreover, we demonstrate that for archived material, for example, for retrospective studies, LCM is the method of choice, while for fresh bone marrow aspirates, acquired at the time of diagnosis, MACS is superior.

Platelet size has diagnostic predictive value for bone marrow metastasis in patients with solid tumors

Though not very common, solid tumor involvement of the bone marrow (BM) may have serious consequences. Recent studies have shown that mean platelet volume (MPV) is a good indicator for BM disease in the differential diagnosis of thrombocytopenia. We investigated the significance of MPV in the diagnosis of BM metastasis in patients with solid tumors. Patients with histologically-verified solid tumors for whom BM biopsy specimens were available (n = 121) and healthy controls (n = 62) were included in this retrospective study. A total of 183 individuals were analyzed. Of the patients, 61 had a diagnosis of BM metastasis (Group A), 60 did not have BM metastasis (Group B). Group B and C (healthy controls) constituted the control group without BM metastasis (n = 122). The mean MPV was 7.0 +/- 0.8 fl in patients with BM metastasis and 8.4 fl in the control group (P < 0.001). A cut-off point of <7.4 fl was found to have significant predictive value according to receiver-operating characteristics curve analysis. This cut-off point had 85% positive predictive value and 90% negative predictive value in the diagnosis of BM metastasis (odds ratio: 53; 95% confidence interval: 20-135), and a sensitivity of 82.7% and specificity of 89.6%. MPV can be used as a reliable marker to guide the clinician as to the likely presence or absence of BM metastasis in patients with solid tumors.

In vitro detection of occult bone marrow metastases in patients with colorectal cancer hepatic metastases.

The purpose of this study was to assess the immunocytochemical status of bone marrow aspirates from patients with clinically isolated hepatic metastases to test the hypothesis that such findings would allow improved patient selection for liver-directed treatment. All patients had biopsy-proven or presumed colorectal cancer metastatic to the liver and were scheduled for an operative procedure for hepatic resection or for hepatic artery catheter and chemotherapy pump implant. Immunocytochemical analysis of bone marrow aspirate smears was performed with a panel of monoclonal antibodies directed toward cytokeratins, Lewis Y antigen and A-33 colorectal epitopes. Data from 80 patients indicated that bone marrow reactivity was present in 9.5 percent of those with resectable hepatic metastases and in 34 percent of those not resected (P = 0.03). No single monoclonal antibody or combination produced better discrimination. Presence or absence of presumed occult colorectal cancer cells in the bone marrow of patients with isolated hepatic metastases is biologically interesting, but not useful in selecting or altering patient management.

Non-specifically labelled cells that simulate bone marrow metastases in patients with non-metastatic breast cancer.

AIMS: To determine whether the presence of disseminated bone marrow tumour cells at diagnosis is a prognostic factor for breast cancer patients at high risk of recurrence or bone metastasis,...

Detection of occult micrometastases in the bone marrow of patients with prostate carcinoma.

A panel of three monoclonal antibodies that recognize membrane and cytoskeletal antigens expressed by epithelial cells (T16, C26, and AE-1) was used in a sensitive immunohistochemical assay to detect tumor cells in bone marrow aspirates from 20 patients with prostate cancer. Bone marrow aspirates from 2/9 (22%) patients with localized prostate cancer (stage B, 0/5; Stage C, 2/4), and 4/11 (36%) patients with metastatic prostate cancer (Stage D1, 0/7 patients; Stage D2, 4/4 patients) had antigen-positive cells in their bone marrow. The patients with localized disease had conventional examinations for metastases, including radioisotope bone scans and examination of bone marrow cytology, which were negative. The serum prostatic specific antigen (PSA) level appeared to correlate with the presence of micrometastases. Those patients with localized disease and antigen-positive cells in the bone marrow had an average serum PSA level of 26.6 ng/ml, while the average serum PSA level in patients without antigen-positive cells was 12.3 ng/ml. In addition, the number of antigen-positive cells detected appeared to correlate with the stage of disease; patients with Stage C prostate cancer had an average of 10 antigen-positive cells per one million bone marrow elements, while patients with Stage D2 disease had an average of 25 antigen-positive cells per one million bone marrow elements. We have demonstrated that immunohistochemical staining of bone marrow aspirates can detect occult bone marrow metastases in patients with apparently localized prostate cancer. Further follow-up of these and a larger number of patients will be require to determine the potential clinical significance of this finding.

Detection of bone marrow involvement in breast cancer with magnetic resonance imaging.

To evaluate the value of magnetic resonance imaging (MRI) in detecting bone marrow metastases in patients with breast cancer. Twenty-three patients with breast cancer in various stages (stage IV, 11; stage III, five; stage II, seven) were evaluated for bone marrow involvement. MRIs of marrow from lumbar spine, pelvis, and proximal femora were obtained with a 1.5-Tesla unit. All patients underwent bilateral bone marrow aspirations and biopsies for histologic evaluation and immunostaining with monoclonal antibody (MoAB) against low-molecular weight cytokeratin (CAM 5.2). Marrow MRI findings were compared with technetium 99m bone scans. Patients with stage II or III disease were monitored for clinical outcome. Possible correlation of MRI findings with serum alkaline phosphatase level was explored. Fourteen of 23 patients showed MRI abnormalities suggestive of metastatic marrow disease (stage IV, nine; stage III, two; stage II, three). In six patients with abnormal MRIs, histology and MoAB immunostaining confirmed marrow involvement (stage IV, five; stage III, zero; stage II, one). In the other eight patients with MRI abnormalities, neither of these methods confirmed the presence of marrow metastasis. Four of five operable breast cancer (stage II-III) patients with an abnormal initial MRI showed additional abnormalities on follow-up examination and developed metastatic disease within 5 to 18 months demonstrable by conventional clinical methods. Conversely, none of the operable patients with negative MRIs developed recurrent disease at 3 to 16 months (Student's t test, P = .01). Nine patients with a normal MRI had no evidence of marrow involvement with histologic or MoAB immunostaining (stage IV, two; stage III, two; stage II, five). Of 14 patients with abnormal MRIs, bone scans were normal in seven and failed to show corresponding abnormalities in six. Elevated serum alkaline phosphatase levels showed a direct relationship with abnormal bone scans indicating extensive bony involvement, but failed to correlate with positive marrow MRIs. MRI is a promising new technique to detect occult marrow involvement in breast cancer patients. There is a good correlation between abnormal marrow MRI and early development of clinical metastatic disease in patients with stage II to III disease.

Immunocytological analysis detects bone marrow metastases in patients with neuroblastoma

Immunocytological analysis detects bone marrow metastases in patients with neuroblastoma

Bone Marrow Biopsy in the Staging of Small Cell Lung Cancer

From April 1982 to December 1987, 71 patients with small cell lung cancer entered a randomized clinical trial, and underwent bone marrow biopsy (BMB) as part of staging procedures. We identified 8 patients (11%) with bone marrow metastases, 6 with extensive disease independently of BMB, and 2 with extensive disease on the basis of the BMB only. BMB determined a change in the stage in only 3% (2/71) of the cases. No differences were found in the hematological parameters of the patients with or without bone marrow metastases. The median survival of the patients with bone marrow involvement was the same (41 weeks) as those with extensive disease but without bone marrow involvement. We conclude that unilateral BMB without aspiration detects a substantial proportion of bone marrow metastases in patients with extensive disease. This fact does not worsen the prognosis. A small proportion of patients with apparently limited disease has bone marrow involvement. The technique therefore contributes, to a small extent, to the definition of the clinical stage of the disease. However, bone marrow involvement is an important data of natural history, and therefore new methods to better assess this peculiar site of the disease are needed.

Immunocytochemistry in the detection of bone marrow metastases in patients with primary lung cancer.

Immunocytochemistry in the detection of bone marrow metastases in patients with primary lung cancer