|Year : 2019 | Volume
| Issue : 6 | Page : 544-546
Giant pulmonary hamartoma with foci of placental transmogrification of the lung
Komal Sawaimul, Namrata Patro, Charusheela Gore, Archana Chirag Buch
Dr. D.Y. Patil Medical College Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth, Pune, Maharashtra, India
|Date of Submission||29-Nov-2018|
|Date of Acceptance||27-Feb-2019|
|Date of Web Publication||17-Oct-2019|
B-49, Old Girls Hostel, Dr. D.Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune - 411 018, Maharashtra
Source of Support: None, Conflict of Interest: None
Pulmonary hamartoma is the most common benign tumor of lung which is composed of mesenchymal tissues and entrapped respiratory epithelium. The size usually varies between 1 and 5 cm, and it commonly occurs in the sixth and seventh decade, with only 6% of cases seen under the age of 30 years with male preponderance. These lesions are indicative of an abnormal proliferation and mixing of the normal components present in the lung tissue. “Placental transmogrification of the lung” is an extremely rare disease entity, with only <30 cases documented till date. The etiology and pathogenesis still remain unclear. Placental transmogrification is a condition where the alveoli resemble the chorionic villi of placenta. This case is presented to highlight the unusual large size (21.5 cm × 18 cm × 11 cm) of pulmonary hamartoma in a young female (32 years) showing areas of placental transmogrification on microscopy. Awareness of this rare entity will help in making definitive diagnosis.
Keywords: Hamartoma, lung pathology, placental transmogrification
|How to cite this article:|
Sawaimul K, Patro N, Gore C, Buch AC. Giant pulmonary hamartoma with foci of placental transmogrification of the lung. Med J DY Patil Vidyapeeth 2019;12:544-6
|How to cite this URL:|
Sawaimul K, Patro N, Gore C, Buch AC. Giant pulmonary hamartoma with foci of placental transmogrification of the lung. Med J DY Patil Vidyapeeth [serial online] 2019 [cited 2021 Jan 23];12:544-6. Available from: https://www.mjdrdypv.org/text.asp?2019/12/6/544/269427
| Introduction|| |
Pulmonary hamartoma is the most common benign tumor of lung which is composed of mesenchymal tissues and entrapped respiratory epithelium. These lesions are indicative of an abnormal proliferation and mixing of the normal components present in the lung tissue. Incidence of pulmonary hamartoma is 0.25%. It commonly occurs in the sixth decade of life, with only 6% of cases seen under the age of 30 years with a 2–4-year-old male preponderance., The lesions are most often peripheral, and their size is usually <5 cm in diameter. Giant pulmonary hamartomas (>9 cm) are extremely rare, and only <11 cases have been published till date.
The word “placental transmogrification of the lung” was coined by McChesney in 1979. It is known to be a very rare disease entity, with only <30 cases documented till date. The etiology and pathogenesis still remain unclear. Placental transmogrification is a condition where the alveoli resemble the chorionic villi of placenta, although it does not include any biological or biochemical properties of a placenta. Radiologically, placental transmogrification of the lung mainly shows bullous changes and presents very rarely as cysts and nodules. Histology characteristically shows papillary structures similar to placental villi surrounding the pulmonary epithelium.
This case is presented to highlight the unusual large size (21.5 cm) of pulmonary hamartoma in a young female (32 years) showing areas of placental transmogrification on microscopy.
| Case Report|| |
A 32-year-old female patient presented with complaints of breathlessness, intermittent fever, and chest pain radiating to back for 6 months. The patient had no significant history or any previous history suggesting any pulmonary pathology. On examination, there was decreased breathing sounds and significant dullness over the left side of the lung. The right side revealed no abnormality. Laboratory investigations showed reports within normal limits. Radiograph of the chest revealed a well-defined homogeneous opacity in the left hemithorax with obscuration of left diaphragm, cardiophrenic angle, and left mediastinal border likely suggestive of an anterior mediastinal mass [Figure 1]a.
|Figure 1: (a) Radiograph of the chest showing a well-defined homogeneous opacity in the left hemithorax. (b) High-resolution computed tomography thorax showing osteoid formation within the mass lesion. (c) Large encapsulated mass measuring 21.5 cm × 18 cm × 11 cm. (d) Cut section showing multiple whitish calcified nodules|
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Ultrasonography-guided biopsy was done to evaluate the nature of the lung mass lesion. The biopsy report was suggestive of a benign chondroid lesion/hamartoma, and surgical excision was advised for definitive diagnosis. High-resolution computed tomography (CT) thorax showed multiple tiny calcific density foci within the mass lesion, and these foci showed osteoid formation. The possibilities suggested were carcinoid, hamartoma, and sclerosing hemangioma [Figure 1]b. However, the bones and soft tissues of the chest wall were normal.
The lung mass was excised and sent for histopathological examination. On gross examination, the mass was 21.5 cm × 18 cm × 11 cm and weighed approximately 1700 g [Figure 1]c. The cut section showed multiple whitish calcified nodular areas which were firm to hard in consistency [Figure 1]d. At places, gelatinous material was seen, and few tiny cysts were noted which were separated by fibrous septae. The mass was well encapsulated.
Microscopy sections showed a variable mixture of mature hyaline cartilage, fat, and smooth muscle [Figure 2]a. Few entrapped clefts were lined by respiratory epithelium. Few foci of papillary projections with predominant vascular areas were also seen resembling immature placental villi [Figure 2]b. These features were suggestive of placental transmogrification of the lung mass. Immunohistochemical stains showed focal positivity for thyroid transcription factor 1 and were negative for CD 10, S100, and vimentin [Figure 2]c and [Figure 2]d. Thus, the possibility of an epithelial origin of these villous structures was suggested. Histopathological examination of the surgical specimen was reported as a giant pulmonary hamartoma with foci of placental transmogrification. Two months' postsurgery, the patient has been on scheduled visits for follow-up, and there has been no evidence of any recurrence.
|Figure 2: (a) Photomicrograph showing a variable mixture of mature hyaline cartilage, fat, and smooth muscle. (H and E, ×100) (b) Foci of papillary projections with predominant vascular areas resembling immature placental villi. (H and E, ×100) (c) Immunohistochemical stains showing focal positivity for thyroid transcription factor 1 (×400). (d) Immunohistochemical stains showing negativity for vimentin (×100)|
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| Discussion|| |
The term hamartoma was introduced by Albrecht in 1904 to describe a tumor-like growth, which was considered to be arising from a developmental anomaly. Now, they are considered as true neoplasms rather than developmental anomalies. Hamartomas are composed of an admixture of mesenchymal and epithelial elements such as cartilage, bone, and fibrous tissue. The incidence lies between 0.25% and 0.32%. It usually occurs between the sixth and seventh decade of life with a male preponderance., Our case is unusual as it was found in a 32-year-old young female patient. Most of the hamartomas are parenchymal lesions, with endobronchial lesions making up only 10%. They usually present as an incidental radiological finding or may sometimes be associated with hemoptysis and obstructive pneumonia.
The size of hamartoma varies from 1 to 5 cm, and the tumor in our case was around four times larger in size. Hamartomas constitute approximately 8% of all “coin” lesions in the chest radiographs which appear as a solitary, round nodules sometimes associated with punctate or popcorn calcification. CT scans depicting specific popcorn calcification is almost pathognomic. Histopathological examination usually shows a predominant chondroid differentiation (80%), with remaining as fibroblastic (12%), fatty (5%), and osseous (3%) differentiation. Pulmonary hamartomas are mostly asymptomatic and show slow growth. Based on the varying histological components of the tumor, hamartomas have been subdivided into chondromatous, leiomyomatous, lymphangiomyomatous, adenofibromatous, and fibroleiomyomatous. Chondromatous hamartoma is the most common subtype which has been shown to be very rarely associated with placental transmogrification as was seen in our case.
Placental transmogrification is a rare and unique lesion of the lung that shows two clinical presentations. It is frequently accompanied by pulmonary cystic lesions., However, rarely it may occur in conjunction with noncystic lesions such as fibrochondromatous hamartoma and pulmonary lipomatosis. Our case is thus rare as these foci of placental transmogrification were present in a case of chondroid hamartoma unlike in other bullous lesions that it commonly associates with. Pulmonary placental transmogrification needs to be clinically differentiated from overexpansion from segmental bronchial atresia, air trapping by a partially obstructing intrabronchial mass, idiopathic giant bullous emphysema, and cystic adenomatoid malformations, especially in the younger patients., Hamartomas are quite difficult to distinguish from malignant neoplasms by nonsurgical techniques; thus, surgical excision is almost always indicated. Definitive diagnosis can, therefore, be made by histopathological examination only.
| Conclusion|| |
This unique case of pulmonary hamartoma is presented to highlight its large size, clinical presentation in a young female, and microscopic association with placental transmogrification. Placental transmogrification being an extremely rare phenomenon; more research is essentially required to discover in detail its etiology and pathogenesis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]