Epidermal growth factor receptor mutations correlated with adenocarcinoma with bronchioloalveolar pattern, (5,16) terminal respiratory unit adenocarcinoma, (21) papillary and micropapillary adenocarcinoma subtypes, (13) micropapillary pattern and
hobnail cell type of adenocarcinoma, (22) and absence of solid growth pattern.
Correlation between morphology and EGFR mutations in lung adenocarcinomas Significance of the micropapillary pattern and the
hobnail cell type.
(32-34) A micropapillary and
hobnail cell type has also been reported to be associated with EGFR mutations.
Concerning histopathology, a bronchioloalveolar carcinoma (BAC) histologic feature and well-differentiated to moderately differentiated grades were earlier reported to predict responsiveness to the EGFR tyrosine kinase (TK) inhibitor and the presence of EGFR mutations (33,34) The finding that the
hobnail cell type and a micropapillary morphology can predict a higher incidence of EGFR mutations in lung adenocarcinomas has been reported more recently.
Histopathological examination revealed that the cystic structures were locally lined by stratified cuboidal epithelium and locally lined by
hobnail cells (Figure 3).
On histopathologic examination, this tumor shows cells with clear cytoplasm and
hobnail cells, and it must be distinguished from other differential diagnoses.
Hobnail cells with moderate to marked nuclear atypia without pleomorphism are characteristic (Figure 7, D).
Typically vaginal CCC show variable morphologic patterns including solid, tubulocystic, and papillary, with presence of
hobnail cells. CCRCC characteristically shows alveolar, acinar, and nested patterns and papillary architecture is not a feature of CCRCC; in addition, a prominent network of branching small, thin-walled blood vessels is characteristic and diagnostically helpful.
Papillary and tubulocystic patterns should be found with
hobnail cells lining the cysts and mononuclear inflammatory infiltrate.[sup][6] The mucicarmine-negative, PAS-positive glycogen imparting the clarity to cells should also be diastase labile.[sup][2],[6]
Nephrogenic adenoma of the urinary bladder is defined as a metaplastic change in the urinary bladder with papillary or cryptic structures which are composed of small hollow tubules similar to mesonephric tubules, which are usually lined by a single layer of bland cuboidal or
hobnail cells, surrounding eosinophilic or basophilic secretions [7].
The presence of
hobnail cells and extracellular mucin are more typical of clear cell carcinoma of the ovary, while a solid and tubular growth pattern with bland cells and a prominent vascular network raises the possibility of a metastasis of clear cell RCC.
Bizarre glandular elements are lined by high-grade, cuboidal, or
hobnail cells.
