Pulmonary placental transmogrification: a difficult pattern in differential diagnosis of pulmonary hamartomas from a tertiary care hospital in Turkey

Abstract

Objective: Pulmonary placental transmogrification (PT) is a benign lesion curable by resection, represented by an unusual peculiar morphological variation including placentoid bullous change in the pulmonary hamartoma. In this retrospective study, we aimed to examine the histopathological features of pulmonary hamartomas in lung, to evaluate the different histological components, especially PT, and to investigate importance of PT pattern and its relationship with other clinicopathological features.

Methods: Thirty-five cases of pulmonary hamartomas were recruited from the records between 2001 and 2021, divided into two groups according to presence of PT, as PT (-) and PT (+) in pathological examination.

Results: 77.1% of all patients were male. There was no significant difference between the two groups in terms of age, sex, comorbidity, presence of symptoms, tumor localization, and radiological findings (P > 0.05). Pulmonary hamartomas were resected totally from 28 patients (80%). Five of these patients (17.9%) had PT components in resection materials with varying degree between 5 and 80%, and all were from male patients. Examination with frozen sections were performed in 15 PT (-) and 5 PT (+) patients but diagnosis with frozen sections was not achieved in any of PT (+) patients. Most of materials included chondroid components (52.22 ± 29.7%) in both groups (P < 0.05).

Conclusion: The placental papillary projections are available patterns associated with a pulmonary hamartoma and these projections observed especially in frozen sections are very crucial to recognize PT pattern in hamartomas, as they can result in confusions in differential diagnosis of malignities.

Keywords: Placental transmogrification; Placentoid bullous; Pulmonary hamartoma.

Fig. 1

Morphological features of placental transmogrification in pulmonary hamartoma. (A) Myxoid and edematous stroma (H&E, x40). (B) Magnified micrograph of A (H&E, x100)

Fig. 2

A. Papillary projections with adjacent area of a lymphoid aggregate (H&E, x40). B. Magnified micrograph of A (H&E, x100). C. Villus-like projections with cartilage and lymphoid aggregates (H&E, x40). D. Magnified micrograph of C (H&E, x100)

Fig. 3

A. The stroma of pulmonary hamartomas with PT contained fibroadipose tissue, blood vessels and many inflammatory cells including the lymphocytes and macrophage, all diffusely dispersed (H&E, x100). B. Prominent epithelial foldings formed the papillary projections and myxoid stroma with vessels in villus-like structure (H&E, x100). C. Epithelial and chondroid components with dense lymphocytic inflammation (H&E, x100). D. Non-ciliated and ciliated columnar epithelial lining of immature placental villi (H&E, x200)