Placental Transmogrification



Placental Transmogrification











This portion of lung shows placental transmogrification. Note the grotesque appearance of the lung parenchyma.






High-power view shows some of the “placentoid” structures image typical of placental transmogrification of the lung. Note the presence of the different sizes and the edematous internal composition.


TERMINOLOGY


Synonyms



  • Placentoid bullous lesion, giant bullous emphysema, pulmonary lipomatosis


Definitions



  • Benign unusual condition characterized by bizarre changes in shape of normal lung parenchyma


ETIOLOGY/PATHOGENESIS


Environmental Exposure



  • Some cases have been associated with tobacco use


Infectious Agents



  • Some cases have been associated with pneumonic process


CLINICAL ISSUES


Epidemiology



  • Incidence



    • This process can be seen in the elderly or young adults


Presentation



  • Cough


  • Fever


  • Pneumonia


Treatment



  • Surgical approaches



    • Complete surgical resection


Prognosis



  • Good


MACROSCOPIC FEATURES


General Features



  • Ill-defined process with complete degeneration of normal lung parenchyma



    • Cystic changes


    • Grape-like structures


    • Soft consistency and yellowish color


Size



  • Ill-defined; may involve entire lobe or lobe segment


MICROSCOPIC PATHOLOGY


Histologic Features



  • Papillary features without cellular atypia or mitotic activity


  • Papillary component may show



    • Myxoid changes


    • Lipomatous changes


    • Edematous changes


    • Minimal inflammatory changes


  • Placental-like pattern


  • In focal areas, residual alveolated tissue may be present


  • In focal areas, residual airway may be seen


  • Lack of pulmonary fibrosis


  • Focal calcifications may be seen


Predominant Pattern/Injury Type



  • Ill-defined


Predominant Cell/Compartment Type



  • Foamy


DIFFERENTIAL DIAGNOSIS


Pneumonia



  • Show areas of acute and chronic inflammation that are usually absent in placental transmogrification



  • Macroscopic features of pneumonia do not resemble the bizarre features of transmogrification


  • Highly unusual for pneumonic process to show presence of adipose tissue


Emphysema



  • Presence of papillary structures with myxoid or lipomatous changes would be unusual for emphysema


  • Entire lung parenchyma is destroyed in transmogrification



    • Leaves little residual alveoli


Papillary Carcinoma

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Placental Transmogrification

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