Interobserver agreement and diagnostic challenges of Congo red staining for amyloid detection on fat pad aspiration biopsies.

INTRODUCTION: Congo red staining of fat pad fine needle aspiration specimens is a method utilized for evaluation of amyloid deposition. However, these specimens can pose diagnostic challenges for cytopathologists. As part of ongoing internal quality improvement measures, the objective of this study was to evaluate the intradepartmental interobserver agreement of these specimens and to identify factors that affect the variability of the interpretations. MATERIALS AND METHODS: There were 7 participants, which included 3 trainees, 3 cytopathologists, and 1 cytotechnologist. Each participant reviewed 50 Congo red stained fat pad fine needle aspiration slides. The interpretations were categorized into 3 groups: negative, indeterminate/suspicious, and positive. The participants also noted any interpretation challenges they encountered for each case. RESULTS: There was only slight interobserver agreement among all participants (κ = 0.133). Stratified by participant group, the interobserver agreement among the trainees was slight bordering on poor (κ = 0.028) and among cytopathologists was fair (κ = 0.249). The highest agreement between 2 observers was between 2 cytopathologists and the level of agreement was moderate bordering on fair (κ = 0.426). There were only 3 cases (6.0%) with full agreement among observers, while in 25 cases (50.0%), there were 2 category differences in interpretations. The primary diagnostic challenge reported by participants was when weak or focal birefringence was encountered as well as cases complicated by poor stain quality and overstaining. CONCLUSIONS: We found only slight interobserver agreement among all study participants. A major area of challenge was cases with weak birefringence resulting in high variance of interpretation among participants.

A case of AA amyloidosis complicated by proliferating pilomatricoma and a review of the literature.

Although AA amyloidosis is primarily caused by inflammatory conditions, associations between AA amyloidosis and solid cancers have occasionally been described. Herein, we report the case of a 48-year-old man in whom resection of a proliferating pilomatricoma with deposition of AA amyloid resulted in remission of concomitant AA gastrointestinal amyloidosis. A rapidly growing, giant, reddish, ulcerated tumor measuring 16 × 13 cm in size was identified on the upper left arm on a visit to our hospital. Gastrointestinal AA amyloidosis was diagnosed from colorectal mucosal biopsy at the same time, and weight loss and profuse diarrhea were clinically evident. As treatment, the tumor was resected with a 10-mm surgical margin. Histologically, the tumor predominantly comprised a lobular proliferation of basophilic cells peripherally, filled with eosinophilic, cornified material and shadow cells with mitoses observed in basophilic cells. Specimens revealed eosinophilic, homogeneous deposits around tumor nests, which were confirmed as amyloid deposits by positive staining with Congo red stain. These deposits were immunohistochemically positive on staining with anti-serum amyloid A antibody. Collectively, proliferating pilomatricoma with AA amyloidosis was diagnosed. After tumor resection, chronic diarrhea resolved and no amyloid deposition was apparent in colorectal biopsy. It is important to remember that if amyloid deposition is present in a tumor, aggressive tumor excision may alleviate systemic amyloidosis.

Evaluation of abdominal fat pad aspiration highlighting challenges to interpretation.

INTRODUCTION: Fine-needle aspiration (FNA) of abdominal fibroadipose tissue is a commonly utilized method for the detection of amyloidosis. While generally regarded as an accurate and specific detection method, the sensitivity is variable. The objective of this study was to investigate the performance of fat pad FNAs in detecting amyloidosis relative to other tissue biopsies. MATERIALS AND METHODS: Fat pad FNA results from January 1, 2014, to December 31, 2022, were catalogued. Clinical data including FNA indication were ascertained for each case. The results of any subsequent tissue biopsy/biopsies evaluated for amyloidosis by Congo red staining were also assessed. Challenges to diagnostic interpretation were explored. RESULTS: A total of 334 fat pad FNAs were identified. The most common indications were peripheral neuropathy (29.3%), cardiomyopathy/heart failure (28.1%), monoclonal gammopathy (27.8%), and multiple myeloma/lymphoplasmacytic lymphoma (21.0%). Cytologic interpretations were: 7 (2.1%) nondiagnostic, 284 (85.0%) negative, 18 (5.4%) indeterminate, 16 (4.8%) suspicious, and 9 (2.7%) positive for amyloid deposition. In our sample, 103 (30.8%) patients had Congo red testing performed on a subsequent surgical specimen(s) including: 3 of 7 of nondiagnostic cases, none which were positive on the subsequent surgical; 70 of 284 negative cases, 27 which were positive on the subsequent surgical; 11 of 18 indeterminate cases, 7 which were positive on the subsequent surgical; 13 of 16 suspicious cases, 2 which were positive on the subsequent surgical; and 6 of 9 positive cases, 3 which were positive on the subsequent surgical. Challenges to FNA interpretation included scant cellularity, focal staining/birefringence, and overstaining. CONCLUSIONS: It is best to view fat pad aspiration versus other tissue biopsy results as complimentary diagnostic tests that should be interpreted in the context of the clinical setting and overall clinical suspicion for amyloidosis.

Hepatic Involvement as the Sole Presentation of Systemic Amyloid Light Chain (AL) Amyloidosis: A Diagnostic Challenge.

Primary systemic amyloidosis is generally a systemic condition and only a few of systemic amyloidosis cases manifest with signs of single-organ involvement. The occurrence of symptoms and signs of hepatic involvement alone in primary systemic amyloidosis is rare, presenting a diagnostic challenge. In this case, a 55-year-old lady presented with nonspecific symptoms such as weight loss and loss of appetite. She was found to have mildly deranged liver function tests with a cholestatic pattern, and there were no apparent risk factors for liver disease. Clinical features of involvement in other organs were notably absent. After ruling out common causes of cholestatic liver disease, we considered the possibility of infiltrative liver disease and arranged for a liver biopsy, which revealed the diagnosis of amyloidosis. In summary, while hepatic deposition is a relatively common consequence of systemic amyloidosis, it is exceptionally rare for a patient to present with clinical features of liver involvement alone. This rarity presents a significant diagnostic challenge. Given the infrequency of this presentation, a diagnosis of amyloidosis should be considered only after diligently excluding other more common causes of hepatomegaly, whether associated with abnormal liver function tests or not.

Amyloidosis in the nasopharynx and larynx: a case report.

Amyloidosis is a disease caused by amyloid deposition in tissues or organs. According to the extent of the lesion, it can be divided into systemic amyloidosis and localized amyloidosis. Amyloidosis originating in the larynx accounts for approximately 0.5% to 1.0% of benign lesions of the larynx; such lesions are relatively rare and mostly localized. Nasopharyngeal amyloidosis combined with laryngeal amyloidosis is even rarer. We herein present a case involving a patient with amyloidosis in the nasopharynx and larynx who presented with a foreign body sensation and hoarseness in the pharynx. Electronic fiber laryngoscopy revealed a smooth neoplasm in the left nasopharynx and left vocal cord. The patient underwent surgical treatment, and the postoperative pathologic examination results suggested amyloidosis. Special staining performed using Congo red and crystal violet was positive, confirming amyloidosis. The patient recovered after surgery, and no recurrence was present at the 3- and 6-month follow-ups.

A rare case of isolated laryngotracheal amyloidosis with airway narrowing and vocal fold involvement.

Primary amyloidosis is a rare condition with 6-10 cases in a million, with focal involvement representing 9%-15% of those cases [1,2]. Isolated tracheobronchial amyloidosis is extremely rare and when present, can result in focal or diffuse thickening of the glottis, trachea and bronchi, leading to hoarseness, shortness of breath, and dysphonia. Computed tomography (CT) usually shows circumferential thickening of trachea and bronchi with or without calcifications and associated airway narrowing of affected segments. MRI demonstrates intermediate to low signal on T1, low signal on T2 and variable heterogeneous enhancement. Multiple conditions can result in thickening of the airway including but not limited to inflammatory, infectious, and neoplastic etiologies. Biopsy with histologic correlation provides a definitive diagnosis. Biopsied tissue demonstrates characteristic apple-green birefringence with Congo red stain. There is no cure for amyloidosis and the prognosis is quite variable depending on the extent of airway involvement. Current treatments are aimed at alleviating symptoms and include bronchoscopic debridement, laser therapy, and balloon dilation with adjuvant radiation therapy. Here, we present a rare case of a 47-year-old male with isolated laryngotracheal amyloidosis with marked airway narrowing and vocal fold involvement.

Oral amyloidosis: A case report and diagnostic algorithm.

Background: Amyloidosis is a distressing and infrequent condition caused by accumulation of abnormally folded proteins as aggregates in the extracellular tissue spaces of the body, leading to destruction of organ structure and function. Presentation of Oral Amyloidosis is generally a rare phenomenon, tongue being the most common site to manifest the disease process. Accurate recognition of the amyloid protein and its sub typing is absolutely critical for clinical management and to assess prognosis such as to avoid misdiagnosis and unwanted, potentially harmful treatment. Case Report: We report a case of 84 year old male patient with an enlarged tongue, who presented with burning sensation and a facial violaceous papules with no other known systemic findings. Incisional biopsy revealed amorphous deposits confirmed for amyloid by congo red stain and Immunohistochemistry. Conclusion: The suspicion of Amyloidosis should always be kept in mind whenever a solitary enlargement of the tongue is noticed. Close follow-up and an entire panel of investigations is mandatory, both to manage recurrences and to monitor the possible advancement of the disease into a full blown systemic form.

Updates in processing of anterior fat pad aspirate for amyloid (with video and sketches).

Fat pad aspiration is a commonly used method for detecting amyloid in tissue. Amyloid is detected in the small blood vessels of the aspirated adipose tissue. Optimum evaluation of amyloid with electron microscopy requires at least 15 blood vessels in the fat pad aspirate. The presence of a significant proportion of adipocytes in the aspirate dilutes the fibrovascular portion. This may compromise the evaluation for amyloid with electron microscopy and in FFPE with proteomic studies by mass spectroscopy for confirmation of the amyloid subtype. This video article describes the updated protocol for processing the anterior fat pad aspirate. It demonstrates how to remove the interference of blood and fatty component in the fat pad aspirate performed by the previously reported procedure.

Vitreous amyloidosis as primary manifestation of disease: case report. / Amiloidosis vítrea como manifestación primaria de enfermedad: reporte de caso.

A 35-year-old woman with progressive decrease of vision in both eyes and with no other associated symptoms, manifested as the only antecedent, the death of her brother due to amyloidosis. The visual acuity was counting fingers at 30 centimetres in the right eye and 20/70 in the left eye. In ophthalmoscopy of the right eye, a white, homogeneous vitreous, that was difficult to assess in detail, was observed, and in the left eye a whitish vitreous with band-like opacities in the cortical region. Vitrectomy was performed in the right eye, and a study with specific stains showed positive for amyloid material. A case is reported of amyloidosis diagnosed with specific stains in a vitreous sample for which the initial and only manifestation was the presence of vitreous opacities. The processing of these samples should be considered in patients with family history, early vitreous opacities, negative results of systemic biopsy, or atypical course of the disease.

Eosinophils: An imperative histopathological prognostic indicator for oral squamous cell carcinoma.

BACKGROUND: Inflammation in tumor microenvironment assists in both promotion and growth of tumor. Tumor-associated tissue eosinophilia (TATE) is the term used when eosinophils are observed in a tumor tissue with inflammatory infiltrate. Although carcinogenesis with inflammation is one of the important hallmarks, the exact role of eosinophils remains unclear. Various studies on oral squamous cell carcinoma (OSCC) that focused on eosinophils reported both favorable and unfavorable prognosis in cancer tissue, because of which the exact function of eosinophils still remains uncertain. AIMS AND OBJECTIVES: The present study aims at identifying the role of TATE in OSCC and in malignant transformation of oral epithelial dysplasia (OED). MATERIALS AND METHODS: The study includes 70 samples that divided into two groups, of which 50 histopathologically proven cases of different grades of OSCC and 20 cases of OED (oral leukoplakia). Congo red stain was used to stain the tissue sections. Each slide was viewed under high power in 10 consecutive microscopic fields for counting of eosinophils. RESULTS: Statistical analysis of values obtained was done using ANOVA, unpaired t-test and Mann-Whitney test. The results were statistically significant (P < 0.05) with a mean total eosinophil count of 2.12 in OED and 4.31 in OSCC. CONCLUSION: The present study showed higher eosinophil counts in OSCC when compared to dysplasia which should prompt for a thorough evaluation of tumor front for invasiveness. Therefore, tissue eosinophil count may be used as an adjunct to predict the malignant transformation of dysplastic lesions to OSCC.

Pindborg tumor: Pathology with special stains.

Odontogenic tumors constitute a wide spectrum of lesions ranging from malignant and benign neoplasms to dental hamartomas, all derived from the epithelial and ectomesenchymal remnants of the tooth forming apparatus. Calcifying epithelial odontogenic tumor (CEOT) is an uncommon, benign epithelial odontogenic tumor first described by Pindborg in 1956. It is a universally accepted eponym for this neoplasm. Pindborg tumor or CEOT is a locally aggressive neoplasm that accounts for 1% of the total odontogenic tumors, with recurrence in 14% of cases. The etiology of this tumor remains an enigma to the clinician. Pindborg suggested that the tumor arises from the remnants of reduced enamel epithelium of an unerupted tooth. Recent studies in literature report that the tumor arises from stratum intermedium. We report a case of Pindborg tumor in a 22-year-old male patient in the left mandibular posterior region. Radiographically, a well-defined radiolucency was associated with unerupted mandibular second molar which was displaced to the inferior border of the mandible. Along with routine haematoxylin and eosin stains, this case reports histopathological findings using Congo red stain and modified Gallegos stain.

Incomplete ileus and hemafecia as the presenting features of multi-organ involved primary systemic AL amyloidosis: a rare case report.

BACKGROUND: AL Amyloidosis is known to be a systemic disease affecting multiple organs and tissue while it's rare that patients present with gastrointestinal symptoms at first and later develop multiple-organ dysfuction. Clinical signs are not specific and the diagnosis is rarely given before performing immunofixation and endoscopy with multiple biopsies. We would like to emphasize the value of precise diagnostic process of AL amyloidosis. CASE PRESENTATION: In this case report, we describe a 56-year-old man who presented with recurrent periumbilical pain for 4 months and gradually worsened over a month. After a series of tests, he was finally diagnosed with primary systemic AL amyloidosis. He was treated with a chemotherapy regimen (Melphalan, dexamethasone and thalidomide) achieving a good clinical response. CONCLUSION: On account of the high misdiagnosis rate, establishing the most precise diagnosis in first time with typing amyloidogenic protein becomes increasingly vital. Although the presenting feature is usually nonspecific, AL amyloidosis ought to be considered when multiple organs are involved in a short period.

Pulmonary arterial hypertension in primary amyloidosis.

Amyloidosis involves extravascular deposition of fibrillar proteins within tissues and organs. Primary light chain amyloidosis represents the most common form of systemic amyloidosis involving deposition of monoclonal immunoglobulin light chains. Although pulmonary amyloid deposition is common in primary amyloidosis, clinically significant pulmonary amyloidosis is uncommon, and elevated pulmonary artery pressures are rarely observed in the absence of other underlying etiologies for pulmonary hypertension, such as elevated filling pressures secondary to cardiac amyloid. In this case report, we present a patient with primary light chain amyloidosis and pulmonary arterial hypertension in the setting of pulmonary vascular and right ventricular myocardial amyloid deposition.

Tumor Associated Tissue Eosinophilia in Oral Squamous Cell Carcinoma: A Histo-Chemical Analysis.

BACKGROUND: Tumor associated tissue eosinophilia (TATE) is believed to play a significant role in biological behavior of the carcinoma. Eosinophils are involved in immune reaction. Various studies have been carried out regarding their role in tumor progression or regulation. In oral squamous cell carcinoma (OSCC), eosinophils are associated with favourable or unfavourable prognosis and hence their role is yet unclear. To compare the tissue eosinophils in OSCC and normal tissue and to correlate the expression of TATE in different grades of OSCC. METHOD: Study comprised 30 cases, 6 normal and 24 histopathologically diagnosed with OSCC. 4 micron thick sections were stained using 1% congo red solution. The sections were examined under high power (×40) and 10 consecutive microscopic fields were studied. The average number of eosinophils were statistically analysed. RESULTS: The tabulated results showed that the median value of tissue eosinophils, increased in OSCC compared to normal mucosa. Analysis on different grades of carcinoma showed a higher TATE in Well differentiated squamous cell carcinoma as compared to other grades. CONCLUSION: The higher eosinophil count in OSCC compare to normal tissue might have a role in stromal invasion and infiltration. TATE can be used as an indicator of favourable prognosis in OSCC.

An evaluation of Congo red fluorescence for the diagnosis of amyloidosis.

Congo red stain apple-green birefringence under polarized light is the most popular method for detecting amyloid; however, it has limitations. The goal of this study was to evaluate if examination of Congo red stain by fluorescent microscopy (FM) significantly enhances the diagnostic yield. Congo red-stained tissue sections were retrospectively and prospectively examined by light microscopy (LM) with and without polarizer and by FM using the Texas red filter and results by each method compared. Congo red-stained amyloid recognized by LM was unequivocally and easily identified by FM in each of 48 cases. In 22 of them, FM either confirmed the presence of a small amount of amyloid or lead to a definitive diagnosis, which was otherwise missed. Eight cases with Congo red-negative by LM were also negative by FM. In 8 cases with a false-positive Congo red stain, FM still detected the signal in 5, but it was absent in 3 cases. In conclusion, Congo red fluorescence improves the diagnostic yield of LM for both positive and negative cases.

Primary systemic amyloidosis as a real diagnostic challenge - case study.

Primary amyloidosis (AL) is a rare variety of plasma cell dyscrasia, the diagnosis of which is often difficult to establish. Pathogenesis of amyloidosis involves extracellular deposition of insoluble protein fibrils in tissues, leading to insufficiency of affected organs. According to various sources, mean survival rate of patients with primary amyloidosis ranges from 12 to 24 months, making primary amyloidosis a disease with a very poor prognosis. Survival rate is significantly lowered in case of cardiac manifestation of amyloidosis (about 6 months survival in untreated patients). In recent years a considerable progress in AL treatment has been observed. Nowadays we are able not only to delay progression of amyloidosis, but also to improve the function of the affected organs. Unfortunately as first signs and symptoms of AL are usually nonspecific, the diagnosis of AL is often delayed, resulting in late introduction of optimal therapy. There are many diagnostic tests which can be used in diagnostic process of amyloidosis, i.e. electrophoresis, serum and urine immunofixation or affected organs and bone marrow biopsy. On establishing the diagnosis in a patient with suspected amyloidosis it should be remembered that particular diagnostic methods vary considerably in sensitivity. The aim of this paper is to present a case report of a 27-year-old patient with primary amyloidosis focusing on diagnostic aspect of this condition. On the basis of this case, the authors would like to emphasize the value of precise diagnostic process, with immunological techniques playing undoubtedly a crucial role.

Diagnosis and typing of systemic amyloidosis: The role of abdominal fat pad fine needle aspiration biopsy.

INTRODUCTION: Systemic amyloidosis (SA) has a broad nonspecific clinical presentation. Its diagnosis depends on identifying amyloid in tissues. Abdominal fat pad fine needle aspiration (FPFNA) has been suggested as a sensitive and specific test for diagnosing SA. MATERIALS AND METHODS: Thirty-nine FPFNA from 38 patients (16 women and 20 men, age range 40-88 years) during a 15-year period were reviewed. Smears and cell blocks were stained with Congo red (CR). A panel of antibodies (serum amyloid protein, serum amyloid A, albumin, transthyretin, kappa light chain and lambda light chain) was used on six cell blocks from five patients. The FNA findings were correlated with clinical and histological follow-up. RESULTS: FPFNAs were positive, confirmed by CR in 5/39 (13%), suspicious in 1/39 (3%), negative in 28/39 (72%), and insufficient for diagnosis in 5/39 (13%) of cases. In all the positive cases, SA was confirmed within 2-16 weeks. Among the 28 negative cases, SA was diagnosed in 21, the rest were lost to follow-up. Among the insufficient cases, SA was diagnosed in four and one was lost to follow-up. Specificity was 100%, whereas sensitivity was 19%. SA typing using cell block sections was successful in three, un-interpretable in one, and negative in two cases. CONCLUSION: FPFNA for SA is not as good as previously reported. This may be due to different practice setting, level of experience, diagnostic technique, or absence of abdominal soft tissue involvement. A negative result of FPFNA does not exclude SA. Immune phenotyping of amyloid is possible on cell block.

Unusual presentation of generalized macular amyloidosis in a young adult.

Macular amyloidosis is a common problem seen dermatology out-patient department. Generalized macular amyloidosis presenting with a poikilodermatous appearance is rare. In our case, an 18-year-old male presented with generalized hypopigmented macules with a poikilodermatous appearance of 10-year duration. His developmental milestones were normal with negative family history of similar complaints. Histopathology of hyperpigmented lesions revealed hyperkeratosis and acanthosis of epidermis and hypopigmented lesion showing only hyperkeratosis. Both lesions were showing the deposition of amorphous, hazy material in the tips of papillary dermis with perivascular inflammatory infiltrate. Congo red staining of the amorphous material was positive for amyloid.