Coal Miners Pneumoconiosis:
Clinical:
This disorder is due to coal dust inhalation and the inhaled carbon is the offending agent (not silica). The "coal macule" is the histologic lesion. Macrophages are not destroyed upon carbon ingestion, but the lesion develops due to back-up of the clearing mechanism. Many of these patients may have a mixed disease (ie: concurrent silicosis) due to heavy exposure to silica in coal mines. The disorder generally requires a period of at least 10 years exposure and it is radiographically indistinguishable from silicosis. The disease extent directly relates to the amount of exposure and the disease does not progress once exposure has been stopped. Many of these patients have a mixed disease, however, due to concurrent silica exposure. As with silicosis, the risk for tuberculosis is increased in patients with coal workers pneumoconiosis [2]. Types of disease include:
1- Simple form: Characterized by small nodular opacities with an upper lobe predominance, which less commonly calcify than in silicosis. Pulmonary function tests remain within normal limits and the disorder is arrested upon discontinuation of exposure.
2- Complicated form: Characterized by large opacities (>1cm) which are radiographically indistinguishable from the conglomerate masses of silicosis. This complicated form is also referred to as "progressive massive fibrosis" and emphysematous changes. FEV1, FVC, and diffusing capacity are all decreased.
3- Caplan's Syndrome: This syndrome is characterized by rheumatoid arthritis with pulmonary rheumatic nodules in coal workers. The nodules typically measure between 0.5 to 5 cm in size and may cavitate. Patients are rheumatoid factor (+). The nodules often develop concomitantly with joint disease, but they may precede the onset of arthritis by months or years.
X-ray:
Computed tomography: On CXR, there are small round nodular opacities and occasionally reticular or reticulaonodular opacities [2]. The nodules are usually 1-5 mm in size and tend to be less well defined compared to those found in silicosis [2]. Calcification of the nodules is seen in 10-20% of patients on CXR- often as a central dot [2]. On CT, small nodules are seen diffusely throughout the lungs, but with an upper lung zone predominance [2]. Calcification of the nodules is found in 30% of patients [2]. Lymph node enlargement is seen in 30% of patients [2]. Egg-shell calcification is uncommon (only 1.3% of patients) [2]. In addition, centrilobular emphysematous changes are common in patients with CWP.
Progressive massive fibrosis with development of conglomerate masses is seen in complicated CWP [2].
REFERENCES:
(1) Radiol Clin North Am 1991 Sep;29(5):931-941
(2) Radiographics 2006; Chong S, et al. Pneumoconiosis: comparison of imaging and pathologic findings. 26: 59-77
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&fit=crop&h=100&q=70&w=100)
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
