HISTOPATHOLOGY SECTION - CASE REPORT
Year : 2008 | Volume
: 51 | Issue : 1 | Page : 67--69
Inflammatory pseudotumor of lymph nodes presenting as pyrexia of unknown origin
H Gulwani, P Chopra
Department of Histopathology, Sir Ganga Ram Hospital, New Delhi, India
Department of Histopathology, Sir Ganga Ram Hospital, New Delhi 110 060
Inflammatory pseudotumor (IPT) is an uncommon benign disorder characterized by proliferation of spindle cells, inflammatory cells, and small vessels. The IPT of lymph nodes is a rare cause of lymphadenopathy that usually affects one or two nodal groups. We describe a 27-year-old male presenting with generalized lymphadenopathy, hepatosplenomegaly and fever for 1 year. Histologic examination of lymph node revealed few remnant lymphoid aggregates with marked sclerosis and numerous anastomosing blood vessels in lymph node parenchyma. Interspersed in between the fibrotic bands was a polymorphic infiltrate composed of lymphocytes, plasma cells, eosinophils, and immunoblasts. Also, many histiocytes, multinucleated giant cells some being Langhan«SQ»s type and at places forming ill-defined granulomas were observed. The presence of granulomas and Langhan«SQ»s type of giant cells can lead to a misdiagnosis of tuberculosis as was also done in the present case. It is thus not only important to be aware of this rare benign pathologic entity while dealing with a case of lymphadenopathy, but also consider it in the differential diagnosis of granulomatous disease.
|How to cite this article:|
Gulwani H, Chopra P. Inflammatory pseudotumor of lymph nodes presenting as pyrexia of unknown origin.Indian J Pathol Microbiol 2008;51:67-69
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Gulwani H, Chopra P. Inflammatory pseudotumor of lymph nodes presenting as pyrexia of unknown origin. Indian J Pathol Microbiol [serial online] 2008 [cited 2021 Jun 17 ];51:67-69
Available from: https://www.ijpmonline.org/text.asp?2008/51/1/67/40403
Inflammatory pseudotumor (IPT) is an uncommon benign disorder characterized by proliferation of spindle cells, inflammatory cells and small vessels. The IPT was first described in lungs, but has been reported in various other extranodal locations including orbits, head and neck, liver, spleen, heart, and lymph nodes.  The IPT of lymph nodes is a rare benign cause of lymphadenopathy.  We describe such a rare case of nodal pseudotumor in a 27-year-old man presenting with generalized lymphadenopathy, hepatosplenomegaly, and fever for 1 year.
A 27-year-old male presented with recurrent fever off and on, loss of appetite and swelling in neck for 4 months. Fever was low grade (99-101°F), associated with profuse sweating. On examination, he was found to have bilateral cervical, axillary and inguinal lymphadenopathy. Chest X-ray showed enlarged perihilar lymph nodes with fibrotic bands extending up to lower zones. Ultrasonography of the abdomen revealed enlargement of periportal, celiac, paraaortic, aortocaval lymph nodes and hepatosplenomegaly. Patient was seropositive for typhoid 4 months earlier. He also had episodes of recurrent tonsillitis. The main laboratory investigations done at the time of admission revealed elevation of erythrocyte sedimentation rate (115 mm/first hour), hemoglobin 9.5 g/dl, total leucocyte count 21 000/mm 3 , platelet 4 68 000/mm 3 , total bilirubin 0.8 mg/dl, serum glutamic oxaloacetic transaminase (SGOT) 21 IU/l, serum glutamic pyruvic transaminase (SGPT) 17 IU/l, and alkaline phosphatase 197 IU/l and total albumin 2.3 g/dl. Serologic screening for specific antibodies to hepatitis A, B, and C virus, human immunodeficiency virus and salmonella were negative. Autoimmune markers including antinuclear antibody (ANA), anti-double-stranded deoxyribonucleic acid (anti-dsDNA) and anti-neutrophilic cytoplasmic antibody (ANCA) were negative. Renal function tests showed mildly raised serum creatinine (2.2 mg/dl) with moderate pyuria and proteinuria.
A cervical lymph node and bone marrow biopsy were done to rule out the possibility of any infectious or malignant etiology. Bone marrow biopsy was normocelluar with mature hemopoietic elements. Lymph node was reported to have large collections of epithelioid cells along with occasional Langhan's giant cells in sinuses and an ill-defined granuloma. The possibility of tuberculosis was suggested. The patient received a full course of antitubercular treatment with rifampicin, isoniazid, pyrazinamide and ethambutol. Despite the completion of treatment, patient did not improve and persistently complained of fever and enlarged lymph nodes.
With a clinical suspicion of sarcoidosis/low-grade lymphoma another lymph node biopsy was planned. The lymph node measured 2 x 1.2 cm 2 . Cut surface was smooth and grayish pink. Microscopically, architecture of lymph node was completely effaced. Only few remnant lymphoid aggregates were observed. No well-preserved lymphoid follicles with germinal centers were seen. There was marked sclerosis/hyalinization of the lymph node parenchyma. In foci, the fibrotic bands were seen in flowing bundles with prominent concentric arrangement and whorling/storiform pattern at places [Figure 1]. Reticulin and Masson's trichrome stains demonstrated abundant fibers around blood vessels and in the parenchyma. Numerous blood vessels were present as a network and as anastomising cords throughout the node. Some of these were surrounded by concentric fibrous tissue [Figure 1], inset. Several vessels were lined by plump endothelial cells. Periodic acid Schiff (PAS) stain highlighted the prominent vascularity. Interspersed in between the fibrotic bands, a polymorphic infiltrate composed of lymphocytes, occasional eosinophils, immunoblasts, and numerous plasma cells with Russell bodies was observed. Another frequent cell type was histiocytes with numerous multinucleated giant cells, some being Langhan's type [Figure 2]. Occasional ill-formed granulomas were also present. However, Ziehl-Neelsen stain for acid fast bacilli was negative. Lymph node biopsy done earlier was reviewed and showed similar findings.
Immunohistochemistry was performed using a standard avidin-biotin-peroxidase complex technique. Primary antibodies used included CD3, CD20, CD68, vimentin, and smooth muscle actin (SMA). Immunostaining for CD3 and CD20 revealed only tiny remnants of lymphocytes throughout the lymph node. The reticulin fibers stained positive with SMA and vimentin. CD68 showed positive staining reaction of histiocytes and giant cells present diffusely in lymph node.
The IPT of the lymph nodes is an uncommon benign self-limiting cause of lymphadenopathy characterized by involvement of one or more nodal groups. Abnormalities are mostly confined to one or two nodal areas.  According to Perrone et al. ,  there are two main patterns of IPT of lymph nodes; the first group includes asymptomatic patients with localized lymphadenopathy and the second group comprises of symptomatic patients with several laboratory abnormalities such as elevated ESR, polyclonal hypergammaglobulinemia, mild anemia, elevated lactate dehydrogenase (LDH), and evidence of one or more enlarged lymph nodes.  The present case had clinical findings similar to second group but was unusual in that the patient had generalized lymphadenopathy along with hepatosplenomegaly. Our patient responded very well to steroids and considerable regression in lymphadenopathy was noted within 1 month of treatment.
Histologically, IPT of lymph nodes is characterized by marked morphological heterogeneity. Moran et al.  have described three stages of evolution depending on extent of fibrosis and inflammatory response. With large areas of fibrosis, the present case fits best in stage III. The unusual morphological feature in this case was presence of numerous multinucleated giant cells, some being Langhan's type along with few ill-defined granulomas. These findings lead to a misdiagnosis of tuberculosis. In developing countries where tuberculosis is an endemic disease, the presence of Langhan's giant cells and granulomas can easily be misconstrued as tuberculous in nature. It is interesting to note that New et al.  have described four cases of IPT of lymph nodes, one of which had small giant cell granulomas and another one had few multinucleated giant cells.
To conclude, this present case describes an unusual case of IPT of lymph nodes morphologically showing abundant giant cells and few ill-defined granulomas mimicking tuberculosis. It is thus not only important to be aware of this rare benign pathologic entity while dealing with a case of lymphadenopathy, but also consider it in the differential diagnosis of granulomatous disease. The histopathological features that help in making the diagnosis of IPT are presence of large areas of fibrosis, vascular proliferation admixed with inflammatory cells especially plasma cells.
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