Studies have shown that the lepidic
component of lung adenocarcinoma was correlated with the ground glass appearance on CT, while the invasive adenocarcinoma component was correlated with the solid parts of part-solid nodules (4).
Among the cases with adenocarcinoma (AC) showing PD-L1 expression, a solid pattern was predominant in 5 and a lepidic
pattern was predominant in 2 cases.
Spectral subclassification of ADC into lepidic
, acinar, papillary, micropapillary, and solid subtypes was also performed.
Pulmonary adenocarcinoma are histologically heterogeneous, presenting a wide range of histologic features including solid growth with mucin production, acinar, papillary, lepidic
, enteric within the current WHO adenocarcinoma classification (2-10).
Bronchoalveolar studies have been reported to be very useful in diagnosis of adenocarcinoma and tumours with lymphangitic or lepidic
Exon 21 point mutations were more common in patients with the lepidic
predominant invasive adenocarcinoma (IAC) subtype (P = 0.022).
In lung adenocarcinoma, nuclear maspin was shown to be a typical feature of the lepidic
growth pattern, whereas increased and combined nuclear and cytoplasmic maspin followed by the loss of maspin characterized the invasive phenotype .
If there are persistent infiltrations, bronchioalveolar carcinoma, now known as lepidic
type of adenocarcinoma, should be included in the differential diagnosis.
In addition, bronchorrhea and the unusual pattern of lepidic
growth of the bronchoalveolar carcinoma can worsen hypoxaemia by impairing diffusion capacity of oxygen.
A discontinuous lepidic
pattern can be seen at the periphery of the lesion, and adjacent alveolar spaces may contain mucin.
For IAC, there are five predominant growth patterns (lepidic
, acinar, papillary, solid, and micropapillary) and four variants (invasive mucinous, colloid, foetal, and enteric) .