Correct!
5. More than one of the above
The right apical nodule in this patient shows features consistent with either benign or malignant etiologies and is therefore the nodule is truly indeterminate. Features favoring a benign etiology for this lesion include the patient’s relatively young age, her lack of a history of malignancy, her lack of a smoking history, and the presence of calcium within the lesion. Features suggesting the possibility of malignancy for this nodule include the presence of a significant component of non-calcified soft tissue in the lesion, the upper lobe location, the presence of spiculation, and the presence of a pleural tail [this latter feature is relatively minor and equivocal]. A number of on-line calculators can be used to assess the likelihood of malignancy when nodules such as this one are encountered. For example, the Mayo Clinic Malignancy Risk Prediction Model (https://www.mdcalc.com/solitary-pulmonary-nodule-spn-malignancy-risk-score-mayo-clinic-model) estimates the probability of malignancy for this 2 cm nodule to be 31.8%, whereas the Brock University calculator (https://www.uptodate.com/contents/calculator-solitary-pulmonary-nodule-malignancy-risk-in-adults-brock-university-cancer-prediction-equation) suggests a likelihood of malignancy of 41.4% for this nodule. The Mayo Clinic Malignancy Risk Prediction Model indicates that serial evaluation for stability is appropriate for nodules with ˂2% probability of malignancy, percutaneous tissue sampling with “lower” probabilities for malignancy (2-20%), and surgery when the probability of malignancy within a solitary pulmonary nodule exceeds 70%. Therefore, serial evaluation of this nodule to detect growth is not an optimal choice. Both percutaneous transthoracic lung biopsy and 18FDG-PET scan are reasonable choices for further evaluation of this patient’s nodule. While surgical lung biopsy could be considered by some to be needlessly invasive for the evaluation of this nodule, it could also be argued that there are enough features that predict that this nodule is malignant that the lack of malignant features at percutaneous transthoracic needle biopsy may not reliably exclude malignancy, and therefore complete surgical excisional biopsy is required to definitively exclude a cancerous etiology for this nodule.
The patient underwent 18FDG-PET scan (Figure 5).
Figure 5. Axial 18FDG-PET scan shows mildly increased tracer accumulation within the peripheral right upper lobe partially calcified pulmonary nodule (arrow). Elevated tracer utilization within the immediately adjacent pleura (arrowheads) is also noted.
Which of the following statements regarding the chest CT is most accurate? (Click on the correct answer to be directed to the tenth of thirteen pages)