Mucinous Adenomyomatous Pulmonary Hamartoma Clinicopathologic, Immunohistochemical, and Molecular Features of 6 Cases

Giulio Rossi, Alberto Cavazza, Camilla Comin, Genny Jocollé, Agita Jukna, Matteo Rotellini, Fabio Davoli (Coresponding Author), Thomas Colby

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Pulmonary hamartoma (PH) may show various combinations of mesenchymal tissues with entrapment of respiratory epithelium. An uncommon variant of PH prevalently consisting of smooth muscle with mucinous proliferation has been reported in literature under several definitions as sporadic reports. We collected a series of 6 leiomyomatous PH associated with mucinous growth from consultation files (3 cases) and multicentric revision of archival files among 128 consecutive surgically resected PH. The lesions have a prevalence for male gender (5:1) and lower lobes (5:1), with a mean age at diagnosis of 61 years. All cases were incidentally disclosed in asymptomatic patients and had an indolent behavior. At histology, 2 cases consisted uniquely of smooth muscle and 4 also showed mature adipose tissue. The mucinous proliferation consisted of a monotonous growth of columnar cells lacking p63-positive basal cells and expressing pan-CKs, MUC5A, and CK7, but negative with TTF-1, napsin, MUC1, MUC2, MUC6, CK20, and CDX2. Smooth muscle was negative with hormonal receptors. Molecular analysis using a multiplex gene panel did not reveal gene mutations, while ALK, BRAF, and ROS1 were negative. In conclusion, we describe a small series of uncommon PH with prevalent leiomyomatous mesenchymal component associated with a mucinous growth (mucinous adenomyomatous hamartoma). Despite the lack of basal cells coating mucinous proliferation and irregular architecture, the favorable outcome and lack of molecular alterations most likely lay for a benign/low-grade tumor. Pathologists should be aware of this unusual occurrence to prevent a diagnosis of overt malignancy, particularly in frozen section, small biopsy, and cytology.

Original languageEnglish
Pages (from-to)273–280
Number of pages8
JournalInternational Journal of Surgical Pathology
Issue number3
Publication statusPublished - May 2021


  • adenomyomatous
  • lung
  • mucinous
  • pulmonary hamartoma
  • surgery

Field of Science*

  • 3.2 Clinical medicine
  • 3.1 Basic medicine

Publication Type*

  • 1.1. Scientific article indexed in Web of Science and/or Scopus database


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