Page 28 - Delaware Medical Journal - November/December 2020

follow-up and research analysis. It is very likely that there are AIS tumors in Group 1 (5-7mm). If so, it’s somewhat surprising that the five-year recurrence rate was 27%.4
Seventeen of Kattepogu’s 45 patients underwent mediastinal lymph
node dissection. It is difficult to interpret the “5-yr Survival by Nodal Sampling” graph without knowing
the adenocarcinoma subtypes and the imaging features of the tumors.4 This is important, as lymph node spread is not seen with Noguchi A and B tumors.
NODULE FOLLOW-UP
There is currently no consensus on the appropriate timing of follow-
up imaging of patients presenting with small CT-detected pulmonary nodules.5 Two schools of thought have strategies that I call aggressive vs. non-aggressive, hasty intervention vs. surveillance. Most investigators also now realize that different follow-up regimens are needed for pure ground-
glass tumors and part-solid ground- glass lesions, reflecting the expected likelihood of malignancy and tumor doubling time.
Several principles guide decision making in evaluating GGOs. All
pure ground-glass tumors are not malignant, and short-term follow-up (three to six months) will often answer whether a lesion is an inflammatory process. And, a rapidly growing GGO is most often an inflammatory or granulomatous lesion; that is just not the natural history if malignant.
Most troublesome is a persistent GGO less than 10mm. Fang is of the opinion that surgery for these lesions that
are unchanged on follow-up may be overtreatment.5 Malignancy for GGOs less than 10mm is 1.3%; for those 10- 19mm, it is 6%.6 Kobayashi concluded that GGOs should be followed for three years, as any growth will appear within that time.7 Others suggest a five-year or beyond follow-up for pure ground-glass tumors. Nakao reported several cases of recurrent tumors five years after
resection.8 However, he was unable to determine whether they were cut-end recurrences or metachronous primary tumors.
The Multicenter Italian Lung Detection (MILD) trial is of most interest, as
the investigators had a wait-and-see (surveillance) approach.9 Seventy-six GGOs were observed with a mean follow-up of 50 months. Forty-eight
of the pure GGOs either resolved or remained stable, but eight progressed. Of the lesions with a solid component smaller than 5mm, 12 of 26 tumors progressed. Four adenocarcinomas were eventually resected, but only
one arose from a part-solid GGO. The authors conclude: progression is very slow for these types of lesions, and this supports a surveillance stratagem.
Ground-glass opacities with a nodular component are of much more concern, particularly if the nodule is 5mm or more. The likelihood of malignancy increases with the size of the lesions and the size of the nodular component. Closer follow-up is advised.7 The
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Del Med J | November/December 2020 | Vol. 92 | No. 6