Ann Thorac Surg 2009;87:950-952. doi:10.1016/j.athoracsur.2008.07.063
© 2009 The Society of Thoracic Surgeons
Case Reports
Placental Transmogrification of the Lung Presenting as a Small Solitary Nodule
Yuichi Saito, MDa,*,
Tomohiko Ikeya, MD, PhDa,
Eishin Hoshi, MD, PhDa,
Nobumasa Takahashi, MD, PhDa,
Katsumi Murai, MD, PhDa,
Yoshinori Kawabata, MD, PhDb,
Thomas V. Colby, MD, PhDc
a Department of Thoracic Surgery, Saitama Cardiovascular and Respiratory Center, Saitama, Japan
b Department of Pathology, Saitama Cardiovascular and Respiratory Center, Saitama, Japan
c Department of Pathology and Laboratory Medicine, Mayo Clinic Scottsdale, Scottsdale, Arizona
Accepted for publication July 9, 2008.
* Address correspondence to Dr Saito, Department of Thoracic Surgery, Saitama Cardiovascular and Respiratory Center, 1696, Itai, Kumagaya, Saitama, 360-0105, Japan (Email: k3699004{at}pref.saitama.lg.jp).
 |
Abstract
|
|---|
Placental transmogrification of the lung is a rare cystic lesion of the lung, which has some histologic resembling to placental tissue. Placental transmogrification of the lung has been considered a variant of unilateral bullous emphysema, but in our case, the patient was a 47-year-old man who had no coexisting emphysema of the lung. Histologically our case showed an interstitial proliferation of clear cells with cystic change interpreted as secondary; we also agree with our colleagues that this proliferation may be the primary event pathogenetically. Surgical resection of this lesion seems to be curative.
|
Introduction
|
|---|
Placental transmogrification of the lung (PTL) is a rare cystic lesion of the lung, first described in 1979 by McChesney [1]. Placental transmogrification of the lung has been reported as an unusual lesion resembling placental tissue histologically, but it also considered a histologic variant of unilateral bullous emphysema. However, the pathogenesis of the lesion is not completely understood. We report a case of PTL in a 47-year-old man who presented with a small nodule, and we discuss the pathogenesis of this lesion.
A 47-year-old man had been suffering from a cough for 6 months. At a neighborhood clinic in May 2005, a chest roentgenogram showed no abnormality, but a computed tomographic scan revealed a 10-mm nodule at the right lower lobe. Nine years previously he had been operated on in another hospital for penile carcinoma, so the possibility of solitary lung metastasis was under consideration.
He was referred to the Saitama Cardiovascular and Respiratory Center in December 2005, at which time his cough had diminished. A thin section computed tomographic scan showed a nodule containing several round spaces filled with air (Fig 1). Although he was a current smoker with a 27 pack-year history of cigarette smoking, emphysema was not observed on computed tomographic scan. It was difficult to perform a biopsy with a bronchoscope or computed tomographic guidance because of the location and size of the nodule.
View larger version (86K):
[in this window]
[in a new window]
|
Fig 1. High-resolution computed tomographic scan shows an only 10-mm nodule containing several round-shaped air spaces like footballs without bullous emphysema in the right lower lobe.
|
|
Surgical excision of the nodule was performed thoracoscopically in December 2005. Histology showed a cystic lesion containing multiple villous structures resembling placental chorionic villi (Fig 2A). The villous structures were composed of cellular and fibrous core, containing a proliferation of benign-looking clear cells. The surface of the core was lined by cuboidal cells (Fig 2B). In the core, dilated vascular spaces lined by flat cells and fatty tissues were also noted. At the periphery of the villous structures, the cellular cores containing clear cells showed continuity with the surrounding normal lung tissue (Fig 3A).
View larger version (155K):
[in this window]
[in a new window]
|
Fig 2. (A) Histologic examination shows villous structure resembling placental chorionic villi with destruction of the lung. The core is various from cellular to fibrous (Hematoxylin and eosin; x2.) (B) The cellular core of villous structure is mainly composed of clear cells (Hematoxylin and eosin; x40.)
|
|
View larger version (123K):
[in this window]
[in a new window]
|
Fig 3. (A) At the border of the villous structure, the cellular core containing clear cells continues to normal lung tissue. (Hematoxylin and eosin; x40.) (B) Immunohistochemistry; epithelial membrane antigen is expressed by type 2 cells (Hematoxylin and eosin; x40.) (C) Clear cells are positive for CD10 (Hematoxylin and eosin; x40.) (D) Flat cells on the vascular space are positive for D2-40 (Hematoxylin and eosin; x40.)
|
|
Immunohistochemical staining showed the surface cells of the villous structure were diffusely positive for epithelial membrane antigen, keratin, and focally positive for thyroid transcription factor-1 (TTF-1), showing type 2 cells (Fig 3B). The clear cells were positive for vimentin and CD10, but negative for CD34, HMB-45, and the above epithelial markers (Fig 3C). Flat cells in the vascular spaces in the core were either positive for CD34 or D2-40, showing that the cores had numerous capillaries and lymphatics (Fig 3D). The histologic diagnosis was PTL.
|
Comment
|
|---|
Placental transmogrification of the lung is a very rare lesion that was first reported by McChesney [1] in 1979, as a peculiar localized bullous emphysematous lesion. From then, only 18 reports of PTL have been published to our knowledge. In 1995, Fidler and colleagues [2] suggested that PTL was a histologic variant of giant bullous emphysema and an unusual locally destructive lesion in the lung related to emphysematous bullae, whereas Mark and colleagues [3] in the same year stated that it is unknown whether this lesion is malformation or a peculiar devolution of localized bullous emphysema [3]. Hochholzer and colleagues [4] noted adipose tissue in villous structures in one case and suggested a relation of PTL to hamartoma of the lung. Xu and colleagues [5] showed that the epithelial invagination of pulmonary hamartoma may develop immature placental villi-like structures, as seen in PTL.
In 2004, Cavazza and colleagues [6] documented for the first time an interstitial clear cell proliferation in PTL and suggested this probably represents the primary event in PTL, and the emphysema-like cystic change is a secondary phenomenon. In their immunohistochemical study, the interstitial clear cells were positive diffusely for CD-10 and focally for vimentin. These findings are similar to those in our case. Most of the reported cases of PTL have been large unilateral bullous lesions that may involve an entire lobe. Small PTLs are distinctly unusual. Ferretti and colleagues [7] described a case of PTL presenting as a 25-mm pulmonary nodule without associated bullous emphysema. Our case is similar, with a 10-mm nodule and no associated emphysema. Histology showed many clear cells in the cellular core as the main feature of PTL, as Cavazza and colleagues [6] stated.
In 2004, Pileri and colleagues [8] reported two cases with pulmonary cysts and micro-nodules, presenting a peculiar interstitial proliferation of both HMB-45 and CD34 positive clear cells. Their cases may be potential differential diagnosis pathologically; however, our case was negative for the above markers.
In conclusion, we report a case of PTL 10 mm in diameter, the smallest case reported to date, and agree with the concept that this lesion is not a variant of emphysema but is caused by a primary benign proliferation of peculiar interstitial clear cells that results in secondary cystic changes.
|
References
|
|---|
- McChesney T. Placental transmogrification of the lung: a unique case with remarkable histopathologic feature Lab Invest 1979;40:245-246.
- Fidler ME, Koomen M, Sebek B, Greco MA, Rizk CC, Askin FB. Placental transmogrification of the lung, a histologic variant of giant bullous emphysema. Clinicopathological study of three further cases. Am J Surg Pathol 1995;19:563-570.[Medline]
- Mark EJ, Muller KM, McChesney T, Dong-Hwan S, Honiq C, Mark MA. Placentoid bullous lesion of the lung Hum Pathol 1995;26:74-79.[Medline]
- Hochholzer L, Moran CA, Koss MN. Pulmonary lipomatosis: a variant of placental transmogrification Mod Pathol 1997;10:846-849.[Medline]
- Xu R, Murray M, Jagirdar J, Delgado Y, Melamed J. Placental transmogrification of the lung is a histologic pattern frequently associated with pulmonary fibrochondromatous hamartoma Arch Pathol Lab Med 2002;126:562-566.[Medline]
- Cavazza A, Lantuejoul S, Sartori G, et al. Placental transmogrification of the lung: clinicopathologic, immunohistochemical and molecular study of two cases, with particular emphasis on the interstitial clear cells Hum Pathol 2004;35:517-521.[Medline]
- Ferretti GR, Kocier M, Moro-Sibilot D, Brichon PY, Lantuejoul S. Placental transmogrification of the lung: CT-pathologic correlation or a rare pulmonary nodule AJR Am J Roentgenol 2004;183:99-101.[Free Full Text]
- Pileri SA, Cavazza A, Schiavina M, et al. Clear-cell proliferation of the lung with lymphangioleiomyomatosis-like change Histopathology 2004;44:156-163.[Medline]
Top
Abstract
Introduction
