Fibrohistiocytic Variant of Hepatic Pseudotumor: An Antibiotic Responsive Tumefactive Lesion.

Inflammatory pseudotumor is a term used to designate inflammation-rich tumefactive lesions. Following the exclusion of specific entities such as IgG4-related disease and other neoplastic entities previously included in this entity, the majority of hepatic pseudotumors show a prominent fibrohistiocytic inflammatory reaction and have been previously categorized as fibrohistiocytic variant of hepatic pseudotumor (FHVHPT). The goal of this study was to examine the clinical, radiologic, histologic, and etiologic aspects of this entity. After excluding neoplastic diseases, we identified 30 patients with FHVHPT from 3 institutions between 2009 and 2019. We extracted demographic and clinical data, liver function tests as well as culture results and radiologic information. Hematoxylin and eosin-stained slides were reviewed for pattern of inflammation as well as its cellular composition. Immunohistochemistry for IgG4 and IgG was performed in all cases. The mean age of the 30 lesions characterized as FHVHPT was 56 years (range: 23 to 79 y). Nineteen patients showed solitary lesions; 11 were multiple. The mean size of the lesion was 3.8 cm (range: 1 to 7.5 cm). On imaging, a neoplastic process or metastasis was the leading diagnostic consideration (n=15, 50%). The most common symptom was abdominal pain (n=14/30); 8 patients presented with symptoms compatible with an infectious process, including fever. The inflammatory infiltrate was dominated by lymphocytes and plasma cells, and in most cases, a prominent histiocytic infiltrate (22/30). Neutrophils were identified in 12 cases, with microabscess noted in 8. Storiform pattern of fibrosis was seen in 14/30 cases; obliterative phlebitis was not identified. Culture identified a microorganism in 4 of 9 cases evaluated. The mean IgG4 count was 9.3 per HPF (range: 0 to 51) with 9 of the 26 (35%) biopsies showing >10 IgG4 positive plasma cells per HPF. The mean IgG4 to IgG ratio was 8% (range: 8% to 46%). A hepatectomy was performed in 4 cases. On broad spectrum antibiotics (n=14) the lesions either resolved or decreased in size. Eight patients did not receive specific therapy, nevertheless, the lesion(s) resolved spontaneously in 6 cases, remained stable or decreased in size in 2 cases. Notably, none of these patients showed evidence of a hepatic recurrence. FHVHPT, a tumefactive lesion that mimics hepatic neoplasia, is histologically characterized by a fibrohistiocytic infiltrate. In the majority of patients FHVHPT represents the organizing phase of hepatic abscess and can be successfully managed with antibiotic therapy.

Diagnosis of cutaneous mycobacterial spindle cell pseudotumor in the absence of typical inflammatory cells: A case report.

Mycobacterial spindle cell pseudotumor (MSP) is a non-neoplastic condition that is characterized by spindle-shaped histiocytes colonized by mycobacteria. MSP is most commonly diagnosed in the immunocompromised and, while MSP can occur throughout the body, the most common sites of MSP involvement are the lymph nodes and the skin. To diagnose MSP, histopathological analysis typically demonstrates the presence of inflammatory cells, in addition to spindle cells and the unequivocal mycobacteria, which guides the diagnosis away from potential neoplasms. If properly diagnosed and treated with appropriate antibiotic therapy, patients tend to experience almost complete resolution of their symptoms. MSP is a rare condition; to our knowledge, there have only been 11 documented cases of cutaneous MSP, including the one introduced in this report. Here, we present a unique case of a 50-year-old female on chronic immunosuppressive therapy diagnosed with cutaneous MSP in the absence of inflammatory cells on pathology.

[Tuberculous pseudotumour, a challenging diagnosis]. / La tuberculose pseudotumorale, un diagnostic difficile.

INTRODUCTION: The pseudotumorous form of tuberculosis is a rare entity. Whatever its location, it can simulate neoplasia by its radiological and/or endoscopic appearances. We highlight the diagnostic difficulties associated with this type of presentation. METHODS: We performed a retrospective study of inpatient records from 2003 to 2016 in the pneumology department of La Rabta Hospital to identify cases of thoracic tuberculous pseudo-tumor. RESULTS: Seventeen patients were identified. The median age was 41 years and their symptomatology was dominated by cough and general debility. All had abnormal radiology with 10 cases of suspect lesions. Fibre-optic bronchoscopy revealed endobronchial abnormalities in 11 cases. The median overall diagnostic delay was 97 days. The diagnosis was confirmed bacteriologically in five cases, histologically in 14 cases and based on clinical presumption in one case. The progression was favourable: 13 patients have been declared cured and four patients are still undergoing treatment. CONCLUSION: Making a positive diagnosis of thoracic tuberculous pseudotumour can be difficult, as bacteriological samples are often negative. This can lead to a significant delay in diagnosis and treatment.

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.

Huge Hepatic Fungal Inflammatory Pseudotumor Misdiagnosed as Primary Hepatocellular Carcinoma.

Fungal inflammatory pseudotumor (FIPT) of the liver is a rare disease that may be mistaken for a malignant tumor. It is difficult to diagnose because of its nonspecific clinical and imaging features. We report the case of a 46-year-old Asian man who presented with a mass in the right upper quadrant of the abdomen. The patient had undergone transcatheter arterial chemoembolization therapy at another institution 6 months earlier, but the mass had continued to enlarge. He had no history of chronic hepatitis B, and the serum α-fetoprotein was negative. Contrast-enhanced ultrasonography and computed tomography images were suggestive of hepatocellular carcinoma. However, ultrasound-guided biopsy revealed features of chronic inflammation. The mass was resected and found to be an FIPT. We discuss the details of the case and review related articles.

Pseudotumoral form of soft-tissue tuberculosis of the wrist.

Tuberculosis is a major public health problem in developing countries. Hand and wrist is a rare localization for extra-pulmonary tuberculosis, a pseudotumoral form of soft tissue tuberculosis of the wrist is exceptional. We report the case of a 45-year-old male presenting with a painful swelling of the dorsal aspect of the right wrist evolving for six months. Clinical study was evoking a ganglion cyst of the wrist. Intraoperatively a pseudotumoral mass with rice bodies was found, suggesting tuberculous tenosynovitis. The histopathological study revealed caseating giant cell granulomas with epithelioid cells. Cultures on Löwenstein-Jensen medium detected Mycobacterium tuberculosis. Synovectomy with removal of all the rice bodies followed by anti-tuberculous chemotherapy provided uneventful recovery.

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.

Pericoronary pseudotumor caused by helicobacter cinaedi.

Cardiac tumors and tumor-like lesions are uncommon; most are true neoplasms. We here report a case of a pericoronary tumor-like lesion surrounding the right coronary artery in a 39-year-old man who presented with fever and chest pain. Although clarithromycin was administered for 1 week, his fever persisted. Helicobacter cinaedi (H. cinaedi) was isolated from blood cultures and found to be sensitive to ceftriaxone. A computed tomography scan showed a tumor-like lesion with no (18)F-fl uorodeoxyglucose uptake surrounding the right coronary artery. After administration of ceftriaxone, the tumor-like lesion diminished in size according to meticulous computed tomography examinations. We therefore concluded that it was caused by H. cinaedi infection. The patient has been followed up closely for 1 year and remains asymptomatic.

Neonatal tuberculosis and cardiac inflammatory myofibroblastic tumor.

A 1-month-old neonate was admitted in respiratory distress. Two-dimensional echocardiography and computed tomography scan showed a mass anterior to the left ventricle and right ventricular outflow tract. A biopsy revealed an inflammatory myofibroblastic tumor. A tuberculin test showed an 18-mm diameter induration. Three of the 6 household contacts were also positive for pulmonary tuberculosis. Antituberculosis medication was started. After 1 year, echocardiography and computed tomography scan showed complete resolution of the mass.

Infectious pseudotumors: red herrings in head and neck pathology.

Infectious pseudotumors are tumor-like growths caused by specific microbial organisms. Proliferating histiocytes in these lesions may show atypical cytology with nuclear pleomorphism and increased mitotic activity, erroneously suggestive of malignancies including carcinoma, sarcoma, and lymphoma. Specific and nonspecific immunohistochemical staining profiles may lead to the consideration of a wide range of benign and malignant neoplastic processes. Two such cases are reported. The first is an obstructive endotracheal mass in an AIDS patient caused by Rhodococcus equi infection. The proliferating histiocyes were cytologically atypical with deeply eosinophlic granular cytoplasm leading to the consideration of oncocytic carcinoma, Hurthle cell carcinoma, and pleomorphic rhabdomyosarcoma. The second case is a nasal mass with a microscopic and immunohistochemical profile suggestive of chordoma and paraganglioma. Special microbial stains revealed intracellular bacilli consistent with Klebsiella rhinoscleromatis. In both cases, microbial virulence factors affecting phagocytosis prolonged their intracellular survival and resulted in active histiocytic proliferation. It is of importance that the surgical pathologist be conscious that some infectious processes can clinically and microscopically mimic malignant neoplasms. Accurately identifying these lesions and the specific causative agent is of particular significance since they can be successfully treated with antibiotics.

Cutaneous mycobacterial spindle cell pseudotumor: a potential mimic of soft tissue neoplasms.

A 55-year-old man with scleroderma treated with prednisone and etanercept presented with enlarging sporotrichoid nodules on the forearm. Microscopically, there were large circumscribed dermal and subcutaneous nodules of spindled and epithelioid cells, resembling a spindle cell neoplasm. Small foci of neutrophils were also present, and a subsequent Ziehl-Neelsen stain highlighted beaded acid-fast bacilli in the interstitium. Tissue culture demonstrated Mycobacterium chelonae. Cutaneous mycobacterial spindle cell pseudotumor is an exceedingly rare lesion, with only 6 previously reported cases. Although these included patients with autoimmune disease receiving immunosuppressive therapy, this is the first case reported in association with a tumor necrosis factor alpha inhibitor, etanercept. Furthermore, this represents the first mycobacterial spindle cell pseudotumor described in association with M. chelonae. Mycobacterial spindle cell pseudotumor should be considered in the differential diagnosis of cutaneous spindle cell proliferations, especially in immunocompromised patients.

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

In this case report, we describe an unusual case of mycobacterial associated inflammatory pseudotumor that occurred in a patient with a previous history of cocaine abuse. We discuss inflammatory pseudotumor (IPT) in general and emphasize the rare entity where an associated mycobacterial infection is seen. The histogenesis is not yet completely understood. The lesion can pose challenges for practicing pathologists and a misdiagnosis of malignancy can occur at multiple facets. A discussion about the differential diagnosis and clues to make the distinction is presented. In addition to spindle cell proliferation, the presence of a background of mixed inflammatory cell infiltrate and foamy macrophages are clues to make the diagnosis. In the case of mycobacteria associated IPT, Acid Fast Bacilli (AFB) stains will easily highlight the organisms confirming the diagnosis.

Pseudotumoral hepatic tuberculosis with pericardial abscess.

We report the postmortem findings in a 28-year-old immunocompetent male patient, a rare case of tuberculous liver abscesses with concomitant pericardial abscess in the absence of pleuropulmonary or splenic involvement, who continued to be a diagnostic dilemma. This case report illustrates the difficulty in reaching the correct diagnosis in case of hepatic masses, which are most often confused with carcinoma of the liver, primary or metastatic and, hence, have been aptly referred to as pseudotumoral hepatic tuberculosis in the past.

Rare pediatric cardiac tumor presentation.

A case of cardiac inflammatory pseudotumor with a unique presentation is reported. This especially rare case belongs to a subset of pseudotumor caused by an infectious etiology. Furthermore, it is unique in that the patient experienced unexplained sinus tachycardia, which resolved with resection of the tumor. This report also emphasizes the importance of multiple imaging methods combined with the usefulness of surgery for treatment and diagnosis.

Nodal inflammatory pseudotumor caused by luetic infection.

Inflammatory pseudotumor of lymph nodes (IPT-LN) represents an unusual cause of lymphadenitis of unknown etiology. Upon the observation of a case of IPT-LN associated with Treponema pallidum (Tp) infection, we analyzed a series of 9 IPT-LN and 9 extranodal IPT (spleen, 4 cases; lung, orbit, gut, skin, and liver) for the presence of Tp, using a polyclonal antibody anti-Tp. At the time of biopsy, none of the patients was suspected for luetic infection, nor specific serologic tests were available. IPT-LN areas extensively involved the nodal parenchyma in 4 cases, whereas they were focal in the remaining 5 cases. Capsular thickening and inflammation (6/9), venulitis (3/9), small granulomas (3/9), and follicular hyperplasia (7/9) were observed in the associated lymphoid parenchyma. Tp were detected in 4/9 cases of LN-IPT and in none of the extranodal IPT. Tp were extremely abundant within the IPT areas and in the perivascular tissues in the surrounding parenchyma, whereas they were scattered within the capsule. In Tp+ cases, marked follicular hyperplasia was the single distinctively associated feature. Double immunostains revealed that Tp were predominantly contained in the cytoplasm of CD11c+ CD163+ macrophages, some of which co-expressed HLA-DR. In addition, scattered S100+ interdigitating dendritic cells also showed intracytoplasmic Tp. This study shows that a significant number of IPT-LN is associated with Tp infection. A spirochetal etiology can be suspected in cases of IPT-LN, independently from the extension of the lesions, especially when pronounced follicular hyperplasia is found. Infection by Tp of macrophages and dendritic cells are in keeping with in vitro data and indicate that immune mediated mechanisms may be involved in the pathogenesis of the lesions.