Clinical History
No previous medical history, complained of a painless, left-supramammary swelling of progressive onset.
Sonography (not shown) reveals a non-homogeneous mass of the upper chest wall.
She was referred for a contrast enhanced CT scan of the chest wall.
Thereafter the lesion was surgically resected.
Imaging Findings
The patient without previous medical history complained of a painless, left-supramammary swelling of progressive onset.
Sonography (not shown) reveals a non-homogeneous mass of the upper chest wall.
She was referred for a contrast enhanced CT scan of the chest wall.
Thereafter the lesion was surgically resected.
Contrast enhanced CT scan of the chest wall shows a rounded, well delineated, encapsulated mass of eight centimeters diameter, located between the left pectoralis minor muscle and the ribs. There is no bone involvement, there are no signs of intralesional necrosis.
There is a pronounced and heterogeneous enhancement after IV injection of iodinated contrast material.
Microscopic examination after complete surgical resection of the mass with on the right side of the figure magnification of the inset (black arrow ) demonstrates lymphoid tissue with highly vascularized hyalin stroma and hyperplastic follicles. There is a stromal plasma cell accumulation and at higher magnification arterioles with thick hyalin wall entering the follicle centre are seen (double arrow).
These findings are highly suggestive of Castleman's disease of hyalin vascular (HV) and plasma cell-rich (PC) subtype. Final diagnosis is giant lymph node hyperplasia or angiofollicular lymph node hyperplasia or Castleman disease of the mixed subtype.
Discussion
The disease was first described by Castleman et al. in 1956 while studying histological presentation of 13 isolated and asymptomatic mediastinal masses. The disease was then classified as prelymphomatous. Actual classification distinguishes localized and multicentric forms of Castleman's disease.
Localized form includes HV subtype (90%), PC subtype and mixed subtype. Prinicipal location is the mediastinum (60-75%), followed by the neck. Clinical presentation is frequently that of an isolated and asymptomatic mass of incidental discovering in a young adult. Symptoms are related to local tumefaction. Systemic symptoms such as asthenia, fever, loss of weight have been described in two thirds of PC subtype, and 3 to 10% of HV subtype. In some PC subtype cases, one can see a polyclonal peak on electrophoresis.
Surgery is curative but local recurrence occurs.
Multicentric form is defined by a peripheral polyadenopathy and multivisceral involvement. This form may present with four histological subtypes: plasmocytic (80-90%), proliferative, accumulative and fibrosed. Onset is around the 6th decade, and systemic signs are more frequent than in localized forms. A monoclonal immunohistochemical protein may be present. Various pathologic conditions have been associated with this form of Castleman's disease: auto-immune diseases, lymphomas, carcinomas, sarcomas such as Kaposi's, acquired or congenital immunodeficiencies.
Viral infections by EBV and KSHV (or HHV8) and dysregulation of the IL-6 secretion are possible causal factors but physiopathological pathways of this disease remain uncertain.
Actual treatment is chemotherapy; the prognosis is poor, with a medical survival of 30 months.
CT findings of Castleman disease consist of well circumscribed, encapsulated, and hypervascular masses with or without focal necrosis or intralesional calcification. Since most of the masses are intrathoracic, US is of less value. Recent studies have shown high signal intensity on T2-weighted MR scans, with a strong enhancement after gadolinium injection making of MR imaging a valuable alternative to computed tomography.
Differential Diagnosis List
Giant lymph node hyperplasia
Final Diagnosis
Giant lymph node hyperplasia
