Incidental pulmonary nodule in a smoker: applying Fleischner criteria in a resource-limited setting

Classification and recommendation:

1. Nodule type: solitary, solid, smooth-margined, non-calcified, 9 mm long axis - i.e. a solid indeterminate nodule in a high-risk patient (age >50, 40 pack-years).
2. Fleischner 2017 guidance for a solitary solid nodule ≥8 mm in a high-risk patient offers three acceptable options: (a) follow-up CT at 3 months, (b) PET-CT, or (c) tissue sampling. The choice depends on clinical context, patient preference, and local resources.
3. In this patient, the nodule is at the lower end of the ≥8 mm category, smooth and solitary, with no suspicious features (no spiculation, no growth documented, no lymphadenopathy). The pre-test probability of malignancy is moderate but not high. A 3-month follow-up CT is the most appropriate first step: it is low-risk, avoids radiation from PET-CT, and will demonstrate growth if the nodule is malignant. PET-CT has limited sensitivity for nodules <8–10 mm and for slow-growing or mucinous tumours, and a negative PET does not exclude malignancy.
4. PET-CT is not the best first test here because: (i) the nodule is small (9 mm), where PET sensitivity is reduced; (ii) there is a 6-week wait and shared scanner capacity with oncology; (iii) a negative result would not allow discharge and would still require follow-up. PET-CT is more useful for characterising a larger nodule or for staging if malignancy is confirmed.
5. Tissue sampling (CT-guided biopsy or surgical resection) is not warranted at this size without growth or suspicious morphology; it carries procedural risk and may be non-diagnostic.
6. Smoking cessation should be addressed at every contact, and the patient should be counselled that the nodule is indeterminate and that follow-up is the safe path.

Counselling:

1. Explain that most small nodules like his are benign (granulomas, scars, intrapulmonary lymph nodes), but that a small proportion are early lung cancers, and that the purpose of follow-up is to detect growth early enough for curative treatment.
2. Explain the rationale for a 3-month interval: it is long enough for a malignant nodule to show measurable growth but short enough to allow prompt action if it does. A shorter interval (e.g. 4 weeks) is unlikely to show change and would add radiation and anxiety without benefit.
3. Explain why PET-CT is not the best first test: it can miss small cancers, and a negative scan would not allow him to be discharged; it would also use scarce scanner time.
4. Discuss the option of the hospital's low-dose CT screening pathway, but note the 4-month wait - this is longer than the recommended 3-month interval and is not a substitute for the recommended follow-up. If the screening pathway can accommodate him sooner, that is acceptable; otherwise, a dedicated 3-month follow-up CT should be arranged.
5. Address smoking cessation explicitly, with referral to a cessation service; this is the single most effective intervention for his long-term risk.

Limitations of the 3-month approach:

1. Interval growth may be missed if measurement is imprecise; use the same reconstruction algorithm, slice thickness, and measurement method (e.g. electronic callipers, volume if available) and compare side by side.
2. Some cancers are slow-growing (e.g. adenocarcinoma in situ, carcinoid) and may not change measurably in 3 months; a stable 3-month scan does not exclude malignancy, and further follow-up (e.g. at 6–12 months, or per Fleischner) is needed.
3. Some cancers are fast-growing and may metastasise within the interval; this is uncommon for a 9 mm nodule but is a reason to ensure the patient knows to return earlier if symptoms develop.
4. Patient anxiety and loss to follow-up are real risks; a robust recall system and clear written information are essential.
5. Radiation dose from repeat CT should be minimised using low-dose technique where appropriate.

Next step:

1. This is now a suspicious nodule (growth from 9 to 12 mm over 3 months, new spiculation). The probability of malignancy is high, and the patient should be discussed at a multidisciplinary team (MDT) meeting.
2. Staging: contrast-enhanced CT of the chest, abdomen, and pelvis (including adrenal glands and liver) to assess for distant metastases; PET-CT for staging if the CT suggests locally advanced disease or if there is suspicion of nodal or distant spread. Brain MRI (or contrast CT if MRI unavailable) if there are neurological symptoms or if the tumour is at high risk of brain metastasis (e.g. small cell, adenocarcinoma).
3. Tissue diagnosis: CT-guided percutaneous biopsy if the nodule is accessible and the result would change management; or surgical resection (e.g. video-assisted thoracoscopic surgery) for both diagnosis and treatment if the nodule is peripheral and the patient is fit. A positive biopsy is not always required before resection of a highly suspicious solitary nodule in a fit patient.
4. Physiological assessment: spirometry and cardiopulmonary exercise testing to assess fitness for surgery; smoking cessation support.
5. MDT discussion should include thoracic surgery, oncology, respiratory medicine, radiology, and pathology.

Staging framework:

• T stage based on size and local invasion (T1a ≤1 cm, T1b 1–2 cm, T1c 2–3 cm, T2a 3–4 cm, etc., per current TNM).
• N stage based on nodal involvement (hilar, mediastinal, supraclavicular).
• M stage based on distant metastases (contralateral lung, pleural, extrapulmonary).
• PET-CT is the standard for detecting occult nodal and distant disease; EBUS-TBNA or mediastinoscopy for nodal sampling if PET is positive.
• Document the staging and MDT recommendation clearly, and communicate the plan to the patient with appropriate support.