Myocbacterium-avium intracellulare associated inflammatory pseudotumor of the anterior nasal cavity

Mycobacterial Spindle Cell Pseudotumor of the Nasal Cavity

BACKGROUND

Mycobacterial spindle cell pseudotumor (MSCP) represents an uncommon tumor-like proliferation associated with nontuberculous mycobacterial infection, i.e., M. avium intracellulare, affecting primarily the lymph nodes of immunocompromised men in their 5th decade. Involvement of the nasal cavity by MSCP is exceedingly rare with only 3 well-documented examples in the literature.

METHODS

A 74-year-old, HIV-negative, man presented with a 0.5-cm nodule of the left nasal cavity clinically presenting as a "nasal polyp." His medical history was significant for colonic adenocarcinoma, cutaneous basal cell carcinoma, and chronic lymphocytic leukemia (CLL) transforming to B-cell prolymphocytic leukemia, responsive to chemotherapy. The patient was diagnosed with prostatic adenocarcinoma treated with radiotherapy two months before the nasal lesion was detected. No lymph node enlargement, pulmonary involvement or hepatosplenomegaly were noticed. The nasal nodule was surgically excised and histopathologically examined to rule out metastatic disease or CLL relapse.

RESULTS

Microscopically, the lesion comprised a well-circumscribed, monotonous, spindle cell population in a vaguely storiform arrangement mixed with a heavy infiltrate of neutrophils and sparse lymphocytes. The spindle cells featured finely granular rich eosinophilic cytoplasm with rounded, oval to epithelioid, or elongated nuclei with vesicular chromatin and one or two distinct nucleoli. The lesional cells lacked overt cytologic atypia and showed occasional regular mitoses. The surface epithelium was intact or focally ulcerated. By immunohistochemistry, the spindle cell population stained strongly and diffusely for CD68 and was negative for AE1/AE3, SMA, CD34, and PSA. CD3 highlighted scattered lymphocytes. Ziehl-Neelsen stain disclosed numerous intracytoplasmic acid-fast bacilli. A diagnosis of MSCP was rendered. No recurrences were observed during a 24-month follow-up period.

CONCLUSION

Although exceptionally rare, MSCP should be considered in the differential diagnosis of nodular lesions of the nasal cavity that are characterized microscopically by marked spindle cell proliferation in a vague storiform pattern, admixed with a lymphocytic or mixed inflammatory infiltrate. A negative medical history for HIV infection and medication-induced immunosuppression should not preclude a diagnosis of MSCP, particularly in extranodal sites. Once the diagnosis is established, prognosis appears to be excellent for nasal MSCP following conservative surgical excision.

Algorithmic Approach to Fibroinflammatory Sinonasal Tract Lesions

Fibroinflammatory lesions of the sinonasal tract are one of the most common head and neck lesions submitted to surgical pathology. When the fibroinflammatory pattern represents the lesion (i.e., not surface reactive ulceration), an algorithmic approach can be useful. Separated into reactive, infectious, and neoplastic, and then further divided based on common to rare, this logical progression through a series of differential considerations allows for many of these lesions to be correctly diagnosed. The reactive lesions include chronic rhinosinusitis and polyps, granulomatosis with polyangiitis, and eosinophilic angiocentric fibrosis. Infectious etiologies include acute invasive fungal rhinosinusitis, rhinoscleroma, and mycobacterial infections. The neoplastic category includes lobular capillary hemangioma, inflammatory myofibroblastic tumor, and NK/T-cell lymphoma, nasal type. Utilizing patterns of growth, dominant cell types, and additional histologic features, selected ancillary studies help to confirm the diagnosis, guiding further clinical management.

Inflammatory Pseudotumor in the Nasal Cavity and Sinuses: A Case Report and Associated Literature Review

Inflammatory pseudotumor (IP) is a clinically aggressive but histologically benign condition of unknown cause. It rarely appears in the nasal cavity and sinuses. Here, we describe a 24-year-old female with the main symptom of right nasal obstruction. Examinations showed dilation in the right maxillary sinus and a pale neoplasm in the nasal cavity. The neoplasm was completely excised under endoscope. Postoperative pathology showed significant proliferation of plasma cells and lymphocytes, indicating the presence of IP. No recurrence was found during 20 months of follow-up. Only 28 cases (10 males and 18 females, average 41.04 years) have been reported on Pubmed. The main clinical manifestations were nasal obstruction, epistaxis, facial swelling and pain, eyeball protrusion, diplopia, and other ocular symptoms. Inflammatory pseudotumor always erodes the surrounding bone and requires active treatments. Surgery is the optimal option with a good prognosis.

Pulmonary Mycobacterium Spindle Cell Pseudotumor in Patient With Liver Transplant

We report a case of liver transplant patient who presented with lung masses, found to be Mycobacterium spindle cell pseudotumors. The masses demonstrated hypermetabolic activities on positron emission tomography. Core biopsy revealed sheets of spindle histiocytic cells with abundant acid-fast bacilli identified as Mycobacterium avium-intracellulare complex. This finding is a rare presentation of Mycobacterium infection, mainly nontuberculous Mycobaterium. It is characterized by a benign, spindle cell mass-forming reaction. Most of the reported cases had acquired immune deficiency syndrome or organ transplant. Histopathology illustrating the proliferation of spindle cell shaped histiocytes containing numerous acid-fast bacilli is the gold standard for diagnosis. The standard treatment has not been well established; previously reported cases followed the standard treatment for Mycobacterium based on organ involvement. Our case is the first case to our knowledge that reports pulmonary Mycobacterium spindle cell pseudotumors in a liver transplant recipient.

Mycobacterium Spindle Cell Pseudotumor Caused by Mycobacterium xenopi: A First Described Association of a Rare Entity Presenting in the Lung

Mycobacterial spindle cell pseudotumor (MSP) is a rare benign lesion characterized by a proliferation of bland spindle-shaped histiocytes with vague granulomatous formation, positive for acid-fast bacilli staining. This lesion is usually reported in the lymph nodes and skin of immunocompromised patients; only 6 cases primary in the lung have been reported in the English literature to this date. In this article, we present the case of a 42-year-old female status post failed kidney-pancreas transplant with subsequent multiple kidney transplants, on chronic immunosuppression, who developed a mass in the left lower lobe consistent with MSP. Mycobacterium xenopi was identified in lung tissue culture, an association never previously described in literature. This case report alerts for the possible association of this rare form of non-tuberculous mycobacteria in the pathogenesis of MSP and highlights the importance of this differential diagnosis in lung masses of immunocompromised patients.

Granulomatous Rhinitis in a Horse due to Mycobacterium intracellulare Infection

Mycobacterial infections in horses are uncommon, but are caused most frequently by Mycobacterium bovis of the Mycobacterium tuberculosis complex or Mycobacterium avium of the M. avium complex. Disease caused by Mycobacterium intracellulare, the second most common species within the M. avium complex, has not been reported in horses to date. Mycobacteriosis in horses most often presents as enteric, pulmonary or, rarely, systemic disease. Here we report a case of M. intracellulare infection in a horse presenting as a granulomatous nasal mass.

Laryngeal Inflammatory Pseudotumour Secondary to Mycobacterium kansasii

BACKGROUND

Inflammatory pseudotumours (IPT) are rare benign tumours characterised by spindle-shaped histiocyte proliferation often mimicking a soft tissue sarcoma. They can occur in different parts of the body and various aetiological factors have been proposed. To our knowledge this is the first case report of IPT of the larynx caused by mycobacterial disease.

CASE REPORT

We report a case of IPT of the larynx in an immunocompromised 81-year-old lady presenting with stridor and dysphagia with known disseminated Mycobacterium kansasii of the lungs.

CONCLUSION

This case demonstrates both the clinical and histological difficulties in making the diagnosis of IPT. A high index of suspicion is needed, and the importance of a multidisciplinary approach in the work-up, diagnosis, and management is highlighted.

Mycobacterial spindle cell pseudotumour: epidemiology and clinical outcomes

INTRODUCTION

Mycobacterial spindle cell pseudotumour (MSP) is a rare disease characterised by tumour-like local proliferation of spindle-shaped histiocytes containing acid-fast positive mycobacteria. The aim of this literature review is to describe the clinical parameters and treatment outcomes of patients with MSP.

METHODS

A literature search was conducted using the search terms related to mycobacteria and spindle cell tumours. A previously unreported stem cell transplant recipient from our institution diagnosed with MSP was also included. Demographics, comorbidities, site of infection, treatment and clinical outcomes were analysed.

RESULTS

Fifty-one patients were analysed. Twenty-six (51%) had HIV infection. Mycobacterium avium complex was the most frequent organism isolated in 24 (47.1%) followed by Mycobacterium tuberculosis complex in eight (16%) cases. Lymph nodes were the most common site of infection (45.1%). Twenty (39.2%) patients received antimycobacterial agents, 12 (23.5%) underwent surgical resection and six (11.8%) received antimycobacterial agents plus surgery. Treatment was successful in 24 (47.1%) patients and failed in 15 (29.4%); 13 of these 15 patients died. Antimycobacterial therapy was significantly associated with successful outcome compared with surgical resection or no treatment (P<0.001).

CONCLUSION

MSP is a rare condition associated primarily with immunodeficiencies. Antimycobacterial therapy is significantly associated with successful outcome.

Tubercular Mycobacterial Spindle Cell Pseudotumour: A Case Report

Pseudotumour is a benign inflammatory lesion. Mycobacterial spindle cell pseudotumour (MSP) is a rare pseudotumour. It is a benign proliferation of spindle-shaped histiocytes containing acid-fast mycobacterium, commonly reported in immunocompromised patients. MSP is usually associated with mycobacterium avium complex (MAC). Here, we present the case of a 38-year-old gentleman with acquired immune deficiency syndrome (AIDS) who presented with low-grade fever for 1-month duration. Clinically, he had generalised lymphadenopathy. Chest X-ray showed miliary infiltration in bilateral lung fields. Lymph nodal biopsy showed spindle-shaped histiocytes filled with acid-fast bacilli on Ziehl-Neelsen (ZN) stain, suggestive of MSP. Immunohistochemical (IHC) stains were positive for CD68, S-100 and negative for CD31, which are consistent with MSP. Polymerase chain reaction (PCR) of the biopsy tissue was positive for MTB. Highly active antiretroviral therapy (HAART) was continued and anti-tubercular therapy (ATT) was started. The fever resolved within two weeks and there was a resolution of lymph nodal swelling by 6 weeks. The diagnosis of MSP associated with mycobacterium tuberculosis (MTB) makes our case interesting. It is of utmost importance to differentiate MSP from Kaposi's sarcoma (KS) and other pseudotumours and to know whether it is of tubercular or non-tubercular origin, as the treatment is entirely different.

Mycobacterium avium Infection of Nasal Septum in a Diabetic Adult: A Case Report

Mycobacterium avium complex (MAC) is primarily a pulmonary pathogen that affects individuals who are immune deficient or immunocompromised. In this report, we describe a very rare case of MAC infection clinically presenting as a nasal polyp in a patient with type 2 diabetes mellitus. This case illustrates an atypical anatomic location for MAC, the anterior nasal septum in nasal cavity, as well as often overlooked cause of immune compromise, diabetes mellitus. We present the laboratory findings that lead to the diagnosis as well as a brief review of MAC infections.

Mucocutaneous Inflammatory Pseudotumours in Simultaneous Mycobacterium avium subsp. avium and Mycobacterium avium subsp. hominissuis Infection in a Cat

Mycobacterial spindle cell 'pseudotumour' has been described only once in cats. This unique proliferation of spindle-shaped histiocytes containing Mycobacterium avium is associated with extensive subcutaneous lesions. We report mycobacterial pseudotumour with invasion of muscular and subcutaneous tissues in a 1-year-old female domestic longhair cat. Lesions involved the facial muscles and nasal cavity, making surgical excision impossible. Necropsy examination revealed additional nodules in the subcutis and muscles of the trunk and submandibular lymph nodes. Genotyping of organisms within these lesions revealed simultaneous infection with Mycobacterium avium subsp. avium and Mycobacterium avium subsp. hominissuis. The microscopical appearance of the granulomas was identical, regardless of the strain of bacterium or anatomical location.

Pulmonary mycobacterial spindle cell pseudotumor in a lung transplant patient: progression without therapy and response to therapy

Mycobacterial spindle cell pseudotumor (MSP) represents a rare, non-malignant, mass-forming reaction to various mycobacterial infections, typically occurring in immunocompromised patients. It is characterized by the proliferation of spindle-shaped fibrohistiocytic cells without the formation of epithelioid granulomas. Without staining for acid-fast bacilli, histological distinction from other spindle cell lesions, including malignancy, can be difficult. Most of the MSP cases reported in the literature have involved lymph nodes, skin, spleen, or bone marrow, but rarely involve the lung. MSP predominately occurs in patients who are immunosuppressed. We present a patient with MSP of the transplanted lung caused by non-tuberculous mycobacteria, in whom both the natural course of the untreated pseudotumor as well as the response to antimycobacterial treatments were observed.

Nontuberculous mycobacteria-associated spindle cell pseudotumor of the nasal cavity: a case report

Mycobacterial spindle cell pseudotumor (MSP) is a rare mass-forming lesion caused by mycobacterial infection, mostly in immunocompromised patients. Since it is composed of a proliferation of spindle-shaped fibrohistiocytic cells without forming epithelioid cell granulomas, histological distinction from other spindle cell lesions is often difficult and its pathophysiology is poorly understood. MSP arising in the nasal cavity is extremely rare, and only two cases have been reported previously. Here we report a case of MSP of the nasal cavity in an 83-year-old man with no evidence of immunodeficient state. The resected tumor consisted of spindle cells, which contained numerous acid-fast bacilli in the cytoplasm. By polymerase chain reaction and sequencing using DNA extracted from the paraffin sections, the bacilli were identified as Mycobacterium intracellulare. Immunohistochemistry revealed that the spindle cells were positive for CD68, CD11c and S100 protein, confirming the histiocytic nature of these cells. They were also positive for CD163 and CD204, suggesting that they showed a phenotype similar to alternatively activated (M2) macrophages and the phenotype might contribute to the maintenance of mycobacterial infection despite apparent immunocompetence of the host.

Mycobacterial spindle cell pseudotumor of the lung

Mycobacterial spindle cell pseudotumor (MSP) is a rare benign lesion characterized by local proliferation of spindle-shaped histiocytes containing acid-fast mycobacteria. Most reported cases of MSP occur in the lymph nodes, skin, spleen, and brain in patients who are immunocompromised, particularly following solid organ transplant and in those with AIDS. This is a case report of a patient with AIDS who presented with cough, generalized weakness, and fatigue, who was found to have multilobar lung masses that were MSP, which to our knowledge has not yet been reported in the literature.