Solitary retroperitoneal angiofollicular lymph node hyperplasia.KC Bapat, HM Malde, AA Pandit, BV Mittal, RP Kedar, RD Bapat, RG Relekar
Dept of Pathology, KEM Hospital, Seth GS Medical College, Parel, Bombay, Maharashtra.
The fine needle aspiration cytology (FNAC) and ultrasound radiologic features of a solitary retroperitoneal angiofollicular lymph node hyperplasia (AFLNH), hyaline vascular type are described. Based on a combination of the two, this diagnosis can be suggested in the differential diagnosis of a retroperitoneal mass.
Keywords: Adolescent, Biopsy, Needle, Case Report, Diagnosis, Differential, Giant Lymph Node Hyperplasia, pathology,surgery,ultrasonography,Human, Male, Retroperitoneal Space,
Angiofollicular lymph node hyperplasia (AFLNH) was first described in 1956 by Castleman et al, hence the eponymous title of Castleman's disease amongst the plethora of other names for the condition, viz. giant lymph node hyperplasia, lymph node hamartoma, angiomatous lymphoid hamartoma, follicular lymphoreticuloma and benign giant lymphoma. Histologically, two distinct variants are recognised - the hyaline vascular type (HV) and plasma cell (PC) type. Earlier accounts of AFLNH described the lesions as being solitary and localised to the mediastinum, which is still the most frequent site of involvement.
We report a case of a solitary retroperitoneal AFLNH with FNAC and ultrasound findings.
A sixteen year old poorly nourished Asian Indian male of low socio-economic status, presented to our hospital's surgery clinic with three months duration of pain in right hypochondrium and gradually increasing abdominal distension. A firm 10 x l0 cm immobile lump in the right hypochondrium and a mild splenomegaly were the findings upon a thorough physical examination.
Apart from a blood picture of hypochromic microcytic anaemia with haemoglobin of 9gm/dl, all other investigations were within normal limits.
Ultrasonography (using a 3.5 MHz transducer) revealed a 10x10cm. discrete mass in the right paraduodenal retroperitoneal area, having the same echotexture as that of spleen [Figure - 1] which was mildly enlarged. Remainder of the abdomen and the entire pelvis were within normal limits.
An ultrasound guided fine needle aspiration was performed using a 22 gauge, 3.8 cm long disposable needle, material spread onto five glass slides which were immediately fixed in 95% ethanol and subsequently stained with hematoxylin and eosin (H & E).
FNAC Findings :
H & E stained smears showed a dispersed polymorphous cell population composed of small, round mature lymphocytes, transformed lymphocytes and occasional plasma cells [Figure - 2]. An occasional cluster of benign spindle cell was also noted.
The patient underwent an exploratory laparotomy with excision of the solitary mass from the paraduodenal retroperitoneal area. Retroperitoneal lymph nodes, remainder of the abdomen and pelvis were unremarkable.
The patient remains well two months after surgery.
The lesion was a solitary, oval, well-circumscribed, thinly encapsulated firm gray mass 10x10x8cm. Cut section showed a gray granular surface with focal pitted areas [Figure - 3]
Histologic features were typical of a hyaline vascular type of AFLNK numerous small follicle centers, some with radially penetrating capillaries entering from the perifollicular tissue. These capillaries had thick hyalinized walls. Some follicle centers were surrounded by a concentric layering of small mature lymphocytes. The interfollicular areas showed marked capillary proliferation with hyalinization of their walls [Figure - 4]
To the best of our knowledge, cytomorphology of Castleman's disease has been described on three occasions in 3 the literature,. In the case reported by Hidvegi et al , the aspirate of a solitary abdominal mass revealed not only a polymorphous lymphoid cell population but also numerous capillaries intermingled with lymphoid cells, closely mimicking the histopathologic appearance of HV type of AFLNI-1.
Stanley et al reported on the diagnosis of central nervous system (CNS) involvement, based on cerebrospinal fluid (CSF) cytology, in a previously diagnosed case of multicentric PC variant of AFLNH who had progressed to an atypical lymphoproliferative disorder with CNS symptoms, at the time of CSF examination.
In the third instance cytologic features have been described only briefly.
The sonographic differential in our case rested between an accessory spleen and an enlarged lymph node of lymphoma. However, the large size and location of the lesion ruled out an accessory spleen. FNAC findings of our case would probably be considered similar to the one reported by Hidvegi et al, but differing in that in all our smears, capillaries were conspicuously absent. The few spindle cells that were present may represent endothelial cells or capsular cells and were not considered contributory to the diagnosis. A polymorphous population of lymphoid cells on FNAC also ruled out a lymphomatous process. In the present case, diagnosis of solitary AFLNH was rendered by histopathologic means. On retrospective review we strongly feel that AFLNH could be suggested as the diagnosis of a large solitary retroperitoneal mass when a polymorphous population of lymphoid cells are seen in an aspirate just as would be seen in aspirate from a reactive lymph node. In the PC variant, one would expect to find a large number of plasma cells and immunoblasts in addition to the above. In such cases, the differential diagnosis would be extensive including rheumatoid arthritis, autoimmune disorders, presence of an adjacent neoplasm, luetic lymphadenopathy, angioimmunoblastic lymphadenopathy, peripheral T cell lymphoma, amongst many others. The diagnosis of a PC variant would then be one of exclusion.
The findings of conventional radiologic and newer imaging techniques in Castleman's disease are not diagnostic. Conventional radiographs show a well-defined soft tissue mass. These lesions are highly vascular on angiography and have a distinctive arterial supply with irregular vascular channels spread throughout the tumour, a dense capillary blush, but no tumour vessels or arteriovenous shunting. Computer assisted tomographic scans demonstrate a well defined homogenous mass of soft tissue density with prompt and homogenous enhancement following contrast: this being more marked in HV than PC type,. Magnetic resonance imaging technique shows a low intensity mass on TA weighted images and higher signal intensity on T-2 weighted images. An isoechoichypoechoic homogenous mass - as in our case resembling an enlarged lymph node, are the findings on sonography.
With the advance of fine needle aspiration techniques and ultrasound delineation of intracavitary lesions, it is possible to diagnose this disease accurately by cytologic methods.
We thank the Dean, Seth GS Medical College and King Edward Memorial Hospital for letting us publish this case material.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]