Tubercular Mycobacterial Spindle Cell Pseudotumour: A Case Report

Area of Science:

• Pathology
• Infectious Diseases
• Oncology

Background:

• Mycobacterial spindle cell pseudotumour (MSP) is a rare benign inflammatory lesion.
• It typically presents as a proliferation of spindle-shaped histiocytes containing acid-fast mycobacteria.
• MSP is commonly associated with Mycobacterium avium complex (MAC), particularly in immunocompromised individuals.

Observation:

• A 38-year-old gentleman with acquired immune deficiency syndrome (AIDS) presented with persistent low-grade fever and generalized lymphadenopathy.
• Chest X-ray revealed miliary infiltrations in both lung fields.
• Lymph node biopsy demonstrated spindle-shaped histiocytes laden with acid-fast bacilli, consistent with MSP.

Findings:

• Immunohistochemical stains were positive for CD68 and S-100, and negative for CD31, supporting the diagnosis of MSP.
• Polymerase chain reaction (PCR) confirmed the presence of Mycobacterium tuberculosis (MTB) in the biopsy tissue.
• The patient received highly active antiretroviral therapy (HAART) and anti-tubercular therapy (ATT), leading to fever resolution within two weeks and lymph node swelling resolution within six weeks.

Implications:

• This case underscores the importance of identifying the specific mycobacterial species in MSP, as treatment differs significantly between tubercular and non-tubercular origins.
• Accurate differentiation of MSP from other conditions like Kaposi's sarcoma (KS) is crucial for appropriate patient management.
• The findings emphasize the need for considering tuberculosis in immunocompromised patients presenting with pseudotumour-like lesions.