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CASE REPORT Table of Contents   
Year : 2010  |  Volume : 53  |  Issue : 4  |  Page : 805-807
Coexistent Kaposi's sarcoma and atypical mycobacterial infection involving lymph node: A case report and review of literature

1 Texas Tech University Health Sciences Center, Lubbock, TX, USA
2 Lubbock Surgical Associates, Lubbock, TX, USA
3 Ameripath, Lubbock, TX, USA

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Date of Web Publication27-Oct-2010


Patients infected with human immunodeficiency virus frequently manifest with rare infections as well as neoplasms. We report an unusual and interesting case of an intranodal Kaposi's sarcoma (KS) with coexistent/concurrent granulomatous lymphadenitis secondary to atypical mycobacteria in a groin lymph node. "Mycobacterium pseudotumor" is a nonneoplastic condition and should be distinguished from true KS as these 2 entities differ in their prognosis and treatment. In this article, we discuss the diagnosis and differential diagnosis of this exceptional clinical and pathologic manifestation.

Keywords: Atypical mycobacteria, granulomatous lymphadenitis, HIV, Kaposi′s sarcoma, pseudotumor

How to cite this article:
Bodhireddy H, Rivas S, Seshadri T. Coexistent Kaposi's sarcoma and atypical mycobacterial infection involving lymph node: A case report and review of literature. Indian J Pathol Microbiol 2010;53:805-7

How to cite this URL:
Bodhireddy H, Rivas S, Seshadri T. Coexistent Kaposi's sarcoma and atypical mycobacterial infection involving lymph node: A case report and review of literature. Indian J Pathol Microbiol [serial online] 2010 [cited 2021 Sep 26];53:805-7. Available from: https://www.ijpmonline.org/text.asp?2010/53/4/805/72101

   Introduction Top

Kaposi's sarcoma (KS) is a rare "malignant spindle cell lesion" often presenting in human immunodeficiency virus (HIV)-infected or otherwise immunocompromised patients. It frequently manifests as a skin lesion. Occasionally, it presents in deep organs, including larynx, lung, stomach, and lymph nodes. Primary lymph node involvement by KS is rare. Due to the immunocompromised state of these patients, concurrent uncommon infections are often seen, particularly atypical mycobacterial infection (AMI). We present a curious case of coexistent KS and AMI in the same lymph node. We could find only one other similar case report in the English language literature.

   Case Report Top

Clinical Information

A 34-year-old man sought medical attention from his primary care physician for an enlarged groin lymph node of 5-6 weeks duration associated with chills and rigors. He was treated with antibiotics with partial response. A computer-assisted tomography scan was negative for other lymphadenopathy in the inguinal region. Due to persistent swelling, an excisional biopsy was performed to exclude lymphoproliferative disorders. Subsequent to the biopsy report, the patient tested positive for HIV. Following this, the CD4 count was 49/μL, the reference range being 410-1590/μL. The patient, a sexually active white male, had no other symptoms at the time of presentation and has been relatively symptom free at approximately 5 months following the lymph node biopsy. The central nervous system status in this patient has also been intact to date. Additionally, the lymph node cultures grew atypical mycobacteria while tests for rapid plasma reagin, viral hepatitis, and toxoplasmosis were negative.


A 3.0 × 3.0 × 2.0 cm lymph node was received fresh in the pathology laboratory that showed areas of hemorrhage on cut section. Multiple sections were taken for formalin fixation and tissue was saved in RPMI (Roswell Park Memorial Park) fluid for flow analysis, following submission for microbiologic cultures under sterile precautions. Hematoxylin and eosin (H & E) sections of the formalin-fixed paraffin blocks showed multiple granulomatous foci consisting of histiocytes admixed with neutrophils and rare multinucleated giant cells. Of note was the presence of solid/nodular areas of spindle cell proliferation within the same lymph node [Figure 1]. These spindle cells exhibited marked cytologic atypia with frequent mitoses. Slit-like spaces with many extravasated red cells and cytoplasmic hyaline globules were also identified. The solid areas were distinctly separate from the granulomas and a working diagnosis of KS and granulomatous lymphadenitis was made. Subsequent work-up, including immunostains against CD34, CD68 showed strong positivity of the spindle cells with CD34 and negative reaction with antibody against CD68 confirming the morphologic impression of KS. The histiocytes in the granulomas were confirmed with positive staining for CD68 [Figure 2]. The histiocytes also demonstrated numerous intracellular fascicles of bacilli by a Ziehl-Neelsen stain for acid-fast bacilli [Figure 3] as well as by a Gomori methenamine silver stain, confirming presence of AMI. Based on H & E morphology and special studies, a diagnosis of coexistent/concurrent KS and granulomatous lymphadenitis secondary to AMI was made.
Figure 1 :Kaposi's sarcoma (KS), upper left; and granulomas of atypical mycobacterial infection, lower right (H and E, ×200); Inset: KS demonstrating spindle cell proliferation, slit-like spaces, and extravasated erythrocytes (H and E, ×400)

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Figure 2 :Positive staining for CD68 in histiocytes in atypical mycobacterial infection, left (immunohistochemistry, ×400); and for CD34 in spindle cells in Kaposi's sarcoma, right (immunohistochemistry, ×200)

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Figure 3 :Acid-fast bacilli within the histiocytes (Ziehl-Neelsen stain, oil immersion, ×1000)

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   Discussion Top

Croxon et al[1] in 1983 first described simultaneous involvement of lymph nodes by KS and mycobacteria in a patient with HIV/AIDS. Subsequently, Langani et al [2] in 1999 reported 3 additional cases of coexistent KS and AMI in lymph nodes of patients with HIV. To the best of our knowledge, no other reports have been found in the English language literature since then. KS, although rare, is the most common primary vascular tumor of the lymph nodes seen commonly as a complication of HIV infection in homosexual men. Nodal KS can also occur rarely as a complication of organ transplantation. [3],[4] All forms of KS are associated with KS-associated herpesvirus or human herpesvirus-8 (KSHV/HHV-8). Lymph nodes involved by KS may show complete effacement of the architecture or more commonly as one or several nodules (as seen in the current case) or as a subtle subcapsular involvement, which may be missed if not examined carefully. Uninvolved nodes may exhibit nonspecific reactive hyperplasia or more often Castleman disease-like features. The morphology of KS, irrespective of location, includes atypical spindle cells with slit-like spaces, mitoses, extravasated red cells, and hyaline globules. The main differential diagnosis of KS particularly in lymph nodes includes "mycobacterial pseudotumor." This is a less common "pseudosarcomatous" spindle cell lesion induced by mycobacteria. Unlike the cells in KS, the spindle cells in this lesion exhibit little atypia and mitoses if any are rare. Slit-like spaces and hyaline globules are usually absent. The acid-fast bacilli are found in both spindle cells and epithelioid cells, unlike in coexistent KS and AMI where the acid-fast bacilli are found only in epithelioid histiocytes and not in spindle cells. In difficult cases, immunohistochemistry is most helpful. The spindle cells in KS are strongly positive for CD31 and CD34 and negative for CD68 and S-100. The reverse is true in the pseudotumor.

Another clinical condition that enters the differential diagnosis is bacillary angiomatosis, a reactive proliferation of blood vessels that may involve lymph nodes. It is also a pseudoneoplastic vascular proliferation characterized by either patchy involvement or coalescent nodules of blood vessels. A Warthin-Starry stain shows bacilli of Bartonella species in the areas with eosinophilic granular material often present admixed with blood vessels in these lesions. These lesions are not associated with KSHV/HHV-8.

In conclusion, the rarely seen histologic combination of atypical mycobacterial lymphadenitis and KS is presented. KS in these situations should be distinguished from benign pseudosarcomatous spindle cell proliferation due to mycobacteria. This distinction is critical as KS may be misdiagnosed as pseudotumor and vice versa with resultant errors in clinical management. Also, this case demonstrates the need for thoroughness in surgical pathology. One should not stop upon arriving at the initial diagnosis, but examine the entire specimen and/or slides in order to rule in or exclude additional entities critical for clinical management. This applies especially to immunocompromised patients who become "warehouses" for multiple infections and/or malignancies.

   References Top

1.Croxson TS, Ebanks D, Mildvan D. Atypical mycobacteria and Kaposi's sarcoma in the same biopsy specimens. N Engl J Med 1983;308:1476.  Back to cited text no. 1
2.Logani S, Lucas DR, Cheng JD, Ioachim HL, Adsay NV. Spindle cell tumors associated with mycobacteria in lymph nodes of HIV-positive patients: Kaposi sarcoma with mycobacteria and mycobacterial pseudotumor. Am J Surg Pathol 1999;6:656-61.  Back to cited text no. 2
3.Finkbeiner WE, Egbert BM, Groundwater JR, Sagebiel RW. Kaposi's sarcoma in young homosexual men: A histopathologic study with particular reference to lymph node involvement. Arch Pathol Lab Med 1982;106:261-4.  Back to cited text no. 3
4.Wang AY, Li PK, To KF, Lai FM, Lai KN. Coexistence of Kaposi's sarcoma and tuberculosis in a renal transplant recipient. Transplantation 1998;1:115-8.  Back to cited text no. 4

Correspondence Address:
Hari Bodhireddy
3903 75th Place, Lubbock, TX 79423
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0377-4929.72101

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  [Figure 1], [Figure 2], [Figure 3]

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