FINAL DIAGNOSIS: Castleman's disease, hyaline vascular type
The postero-superior mediastinum is an exceedingly rare location for the Castleman's Disease, hyaline vascular type. It is likely that this mass arose from one of the posterior intercostal lymph nodes, situated in the paravertebral region, however the capsule was not readily seen and the sinuses were not apparent. No etiology was found, there was no autoimmune disease and no immunodeficiency syndrome. She recovered well following the surgery and was well and alive two years later, having resumed her daily activities.
Almost all previous cases of Castleman's Disease, hyaline vascular type were described in the anterior mediastinum. Two cases were reported, at one lateral intercostal space, mimicking a chest wall tumor, and arising from an intercostal lymph node (6,7) (Table 1). Both reports mentioned the encapsulation of the lesion and the lack of involvement of neighboring structures.
|Authors||Age and Sex||Location, Size||Time, Diagnosis/ Surgery||Pathology||Follow-up|
|Matsuda, 1988||69, Male||Left lateral chest wall, 2nd ICS†, 5.5cm||9 years, increase in size||CD, HV with encapsulation||Alive and well at 3 yrs|
|Parrot, 1989||42, Female||Anterior chest wall, 2nd IC‡, 6cm||Immediate removal||CD, HV with encapsulation||None|
|Our Case, 1997||32, Female||Right 3rd IV§ foramen, 3cm||5 yrs Increase in size, discomfort||CD,HV nerve destruction||Alive and well at 2 yrs|
†ICS: Intercostal Space, ‡IC: Intercostal, §IV: Intervertebral, CD,HV: Castleman's Disease, Hyaline Vascular Type
In hyaline vascular Castleman's disease, the adherence by an involved lymph node to the adjacent soft tissue has been described (10), however encapsulation and self-limitation are constant features of hyaline vascular Castleman's disease. Hyaline vascular Castleman's disease usually does not invade and replace neighboring structures. Our case is unique because it exhibits local invasion of adjacent structures and questions the possible aggressiveness of the hyaline vascular type, classically considered a hamartomatous or inflammatory lesion rather than a neoplasm. Surgery (which is curative) is the preferred treatment over close observation, in all cases.
In 1990, Rosai (5) suggested that the onset of Kaposi sarcoma-like neoplasms in hyaline vascular Castleman's disease could be mediated by the production of angiogenic factors by the activated lymphoid cells. In 1993, Frizzera (3) commented that the factors responsible for angiogenesis and the cellular growths that characterize hyaline vascular Castleman's disease remain to be determined. We think that angiogenesis is probably one determining factor in the local invasiveness seen here. More observations are needed to understand the potential behavior of the hyaline vascular type.
The patient is free of recurrence 7 years after the excision. After this case was accepted for this series, there have been two reports of Castleman's Disease in the posterior fossa (11, 12).
Contributed by Pascale Hummel MD, Vallo Benjamin MD, David Zagzag MD, PhD