Author of

• 12769

  +

  P3.18 - Poster Session 3 - Pathology (ID 177)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Pathology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 12778

    +

    P3.18-009 - Clinicopathological characteristics of primary lung mucinous adenocarcinoma in surgically resected cases (ID 1850)

    09:30 - 09:30  |  Author(s): H. Ichinokawa
    • Abstract

    Background
    Primary mucinous adenocarcinomas (MA) are relatively rare, and the clinicopathological characterisics have remained unclear. The aim of this study was to clarify the clinicopathological characteristics of MA.

    Methods
    We selected MA from 1450 cases of surgically resected primary lungWe selected MA from 1450 cases of surgically resected primary lung adenocarcinoma. The clinicopathological characteristics of MA (30 cases) were analyzed.

    Results
    MA showed a high rate (22/30, 73%) of tumor location in the lower lobe. Vascular invasion was observed in 6 cases (20%). Pulmonary metastasis was observed in 5 cases (17%). Lymphatic permeation was present in 1 case (3%). Pleural invasion was observed in no cases. Lymph node metastasis was present in 1 case (tumor size: 75mm, 3%). MA showed a significantly higher rate of cases aged 65 and over, tumor location in the lower lobe and pathological N0 stage cases, when compared with the other of adenocarcinoma. Furthemore, MA displayed a lower frequency of plural invasion, lymphatic permeation, and vascular invasion, and a high frequency of pulmonary metastasis. We compared the frequency of invasive cases in the two groups with respect to their size (tumor size; TS). In MA, the frequency of invasive cases in TS ≦ 3cm, 3cm < TS ≦ 5cm and TS > 5cm was 11% (2/18), 50% (2/4), 62% (5/8), respectively. In the other types of adenocarcinoma, the frequency of invasive cases in TS ≦ 3cm, 3cm < TS ≦ 5cm and TS > 5cm was 89% (918/1027), 98% (274/281), 100% (112/112), respectively. Therefore, even as TS became bigger, MA displayed lower invasive capacity. We compared the frequency of recurrence cases in the two groups.MA showed local recurrence in 3 of 30 cases (10%), no incidents of distant metastasis. The tumor size of all 3 cases showed more than 5 cm. Pulmonary metastasis showed 1 case (3%) in same side, 2 cases (7%) in the both side. MA showed a significantly lower rate of pulmonary metastasis and distant metastasis (P < 0.05), when compared with the other of adenocarcinoma.

    Conclusion
    The pathogenesis of MA might differ from that of lung adenocarcinoma without MA based on higher rate of tumor location in the lower lobe and recurrence of pulmonary metastasis. MA less than 5cm may be treated as a local disease and could omit mediastinum lymph node dissection.