ALK-positive histiocytosis: an expanded clinicopathologic spectrum and frequent presence of KIF5B-ALK fusion.

In 2008, we presented three cases of ALK-positive histiocytosis as a novel systemic histiocytic proliferation of early infancy with hepatosplenomegaly and dramatic hematological disturbances. This series of 10 cases (including the original three cases) describes an expanded clinicopathological spectrum and the molecular findings of this histiocytic proliferation. Six patients had disseminated disease: five presented in early infancy with eventual disease resolution, and the sixth presented at 2 years of age and died of intestinal, bone marrow, and brain involvement. The other four patients had localized disease involving nasal skin, foot, breast, and intracranial cavernous sinus - the first three had no recurrence after surgical resection, while the cavernous sinus lesion showed complete resolution with crizotinib therapy. The lesional histiocytes were very large, with irregularly folded nuclei, fine chromatin, and abundant eosinophilic cytoplasm, sometimes with emperipolesis. There could be an increase in foamy histiocytes and Touton giant cells with time, resembling juvenile xanthogranuloma. Immunostaining showed that the histiocytes were positive for ALK, histiocytic markers (CD68, CD163) and variably S100, while being negative for CD1a, CD207, and BRAF-V600E. Next-generation sequencing-based anchored multiplex PCR (Archer® FusionPlex®) performed in six cases identified KIF5B-ALK gene fusion in five and COL1A2-ALK fusion in one. There was no correlation of gene fusion type with disease localization or dissemination. The clinicopathological spectrum of ALK-positive histiocytosis is broader than originally described, and this entity is characterized by frequent presence of KIF5B-ALK gene fusion. We recommend that every unusual histiocytic proliferative disorder, especially disseminated lesions, be tested for ALK expression because of the potential efficacy of ALK inhibitor therapy in unresectable or disseminated disease.

Polymerase chain reaction for detection of Mycobacterium tuberculosis in papanicolaou-stained fine needle aspirated smears for diagnosis of cervical tuberculous lymphadenitis.

A polymerase chain reaction (PCR) protocol for detecting IS6110 repetitive insertion sequence of Mycobacterium tuberculosis (MTB) was tested on archival Papanicolaou (Pap)-stained fine needle aspirated (FNA) smears from 24 patients with cervical tuberculous lymphadenopathy and 30 negative controls. The protocol involved protease digestion or phenolchloroform extraction, and simple or nested PCR, with PCR amplification of human beta-globin gene for internal control of DNA quality. Sensitivity of 50% and specificity of 100% were obtained. Sensitivity in smears showing necrosis without granuloma was 70% (7/10), whereas it was 36% (5/14) in smears with presence of granuloma. On the other hand, sensitivity of 18% (4/22) was obtained using FNA acid-fast stain, 25% (1/4) for acid-fast stain in histological section, 50% (2/4) for culture, and 100% (8/8) for PCR of fresh specimens. PCR for MTB detection in Papanicolaou-stained slides is a practical and valuable method when no fresh specimen but only Pap-stained smear is available.

Bronchiolitis obliterans organizing pneumonia caused by capsule-deficient cryptococcosis.

A 67-year-old diabetic man presented with progressive multifocal myeloradiculopathy for 6 months, with no pulmonary symptoms. A chest x-ray and CT scan of the lungs revealed bilateral multiple nodular infiltrates in the right upper lobe and the lower lobes bilaterally, mimicking metastases. A thoracoscopic lung biopsy demonstrated bronchiolitis obliterans organizing pneumonia caused by capsule-deficient cryptococcosis.

Histopathologic characteristics of pulmonary adenocarcinomas with and without EGFR mutation.

UNLABELLED: EGFR mutation played crucial role for responsiveness of non-small cell lung cancers to EGFR tyrosine kinase inhibitors. Almost the mutations were present in adenocarcinomas. Few had studied on histopathologic correlation with EGFR mutation in pulmonary adenocarcinomas. To obtain better view on pathobiology of pulmonary adenocarcinomas, we correlated exons 19 and 21 mutations with various histopathologic features by dissecting particular histological patterns from 60 surgically resected adenocarcinomas. RESULTS: Gland-forming pattern, including bronchiloloalveolar carcinoma (BAC), well-formed acinar, and poorly-formed acinar patterns more frequently contains EGFR mutations than solid pattern (72.7% vs. 23.1%, p = 0.002). EGFR mutations of each within the gland-forming pattern are not significantly different. Micropapillary pattern revealed less exon 19 mutations than the gland-forming pattern (12.5% vs. 66.7%, p = 0.018), but tended to have more Exon 21 mutations than the others (33.3% vs. 11.9%, p = 0.10). Tumors predominated by BAC pattern more commonly had exon 19 mutations than non-BAC predominated tumors (68.8% vs. 39.5%, p = 0.046). EGFR-mutated tumors comprised less proportion of papillary pattern than tumors without mutation (mean = 1.5% vs. 11.2%, p = 0.049). Terminal respiratory unit (TRU) histology was associated with more EGFR mutations (72.4% vs. 42.1%, p = 0.036). Tumors smaller than 3.5 cm had more EGFR mutations than larger tumors (73.1% vs. 41.9%, p = 0.018). CONCLUSION: High frequency of the mutation does not present only in BAC pattern, but also in well-formed and poorly-formed acinar patterns, suggesting them as usual spectrum of EGFR mutated adenocarcinomas. Other characteristics of EGFR-mutated adenocarcinomas include TRU-type histology, smaller size, and less solid phenotype.

Sudden, unexpected death in cardiac transplant recipients: an autopsy study.

BACKGROUND: Clinical studies indicate that sudden death (SD) is common after heart transplantation. Autopsy reports of such patients are sparse. METHODS: We performed a retrospective study of clinical and pathologic findings on all autopsied patients who underwent heart transplantation at our institution from January 1984 to July 2002. RESULTS: There were 74 patients who survived >2 months. Of these, 28 (37.8%) died suddenly. The major causes of sudden death (SD) included acute cellular rejection (ACR) (n = 11, 39.3%) and graft coronary artery disease (GCAD) (n = 11, 39.3%). In 9 patients (32.1%), there was no anatomic cause of death. These deaths, assumed to be primary arrhythmic death (PAD), occurred 5 to 36 months post-transplantation. Pre-transplant diagnosis of idiopathic dilated cardiomyopathy (IDCM) was more common in SD (13 of 28, 46.4% vs 9 of 46, 19.6%; p = 0.014). Hypertrophy was not statistically different in SD vs non-SD (79.4% vs 88.4%; p = 0.38). Coronary thrombosis was also not statistically different in sudden GCAD deaths vs non-sudden GCAD deaths (3 of 11, 27.3% vs 8 of 13, 61.5%; p = 0.09). ACR SD patients had fewer episodes of ACR in biopsies than ACR non-SD patients (93 of 190, 48.9% vs 99 of 159, 63.3%; p = 0.01). Biopsies with Quilty lesions (QL) were more frequent in patients with SD (206 of 461, 44.7% vs 243 of 710, 34.2%; p < 0.001). QL were more common in patients with GCAD (44.4%) and ACR (39.6%) than in patients who died of infection (25.7%; P < 0.001 and p < 0.01, respectively). CONCLUSIONS: SD after cardiac transplantation is common (37.8% of all deaths). ACR, in the first year, and GCAD, afterwards, are associated with SD. PAD occurred in 32.1% of SD cases, 5 to 36 months after transplantation. Pre-transplant diagnoses of IDCM and QL are more common in SD. Surprisingly, cardiac hypertrophy is not increased and coronary thrombosis is not more frequent in patients who died suddenly.

Immunoperoxidase staining for C4d on paraffin-embedded tissue in cardiac allograft endomyocardial biopsies: comparison to frozen tissue immunofluorescence.

C4d deposition in microvasculature is a marker for humoral rejection. The authors compared a recently developed C4d immunoperoxidase (IP) method for paraffin-embedded tissue to immunofluorescence (IF) of frozen tissue. Of 315 frozen endomyocardial biopsies with IF staining for C4d, 280 were negative and 35 were positive. Negative controls were 17 negative biopsies and 11 biopsies with myocyte necrosis. The extent of IP and IF staining was graded as 0 to 3+. Staining intensity and the number and type of positive vessels were recorded. Staining patterns in Quilty lesions (QL) and foci of acute cellular rejection (ACR) were also evaluated. In 34 biopsies with sufficient tissue, IP criteria of 2+/3+, or more than 10 to 20 positive vessels per 10 high-power fields detected 25.0% (1/4), 18.2% (2/11), and 84.2% (16/19) of 1+, 2+, and 3+ IF-positive biopsies, respectively, without false positives. Considering C4d IF 3+ as positive resulted in 84.2% (16/19) sensitivity and 93.0% specificity (40/43). Intensely stained capillaries predominated in six of seven biopsies when more than 100 capillaries per 10 high-power fields were positive. Seventy percent (7/10) of IP 2+ and 3+ biopsies showed positive capillaries in QLs, while 36.4% (4/11) of IP 1+ and negative biopsies did. All eight IP 2+/3+ biopsies showed positive capillaries in ACR foci, while 25.0% (1/4) of IP-negative biopsies did. Capillary staining in QLs and areas of ACR reflects overall C4d deposition. In conclusion, IP staining of 2+/3+ is highly sensitive and specific for C4d positivity. The authors recommend considering 2+ and 3+ as positive staining when using the IP technique.

Metastatic potentiality of micropapillary and conventional histological patterns: a comparative study of 82 pulmonary adenocarcinomas.

BACKGROUND: The recently described micropapillary pattern (MPP) is potentially a strong unfavorable prognostic marker for adenocarcinoma of the lung. None of the previous studies compared the association to nodal metastasis between conventional histological patterns and MPP. METHOD: Histological patterns (1=solid, 2=poorly formed acinar 3=well formed acinar, 4=papillary, 5=bronchioloalveolar), and MPP were semiquantitatively evaluated in 82 pulmonary adenocarcinomas and correlated with nodal status. RESULTS: Mean percentages of pattern 1 and 2 are higher in node positive (N+) group (33.9% vs 19.3%, p=0.046; and 20.8% vs 13.4%, p=0.19, respectively). Analysis of the combined amount of pattern 1 and 2 revealed increased statistical significance (54.6% vs 32.5%, p=0.007). Mean percentages of pattern 3, 4 and 5 tended to be lower in N+ group (22.8% vs 29.4%, p=0.24; 2.8% vs 6.2%, p=0.33; and 17.9% vs 31.2%, p=0.053, respectively). Analysis of the combined amount of pattern 3, 4 and 5 showed increased statistical significance (43.3% vs 66.8%, p=0.005). Mean percentage of MPP was higher in N+ group (28.3% vs 11.3%, p=0.0007) after excluding the cases with more than 80% percent of pattern 1 and 2. The criterion of MPP > or = 20% or combined pattern 1 and 2 > 50% of tumor is strongly associated with nodal metastasis (p=0.0015). Pattern 1 has the highest rate of correspondence of having a similar pattern in metastases (18/26, 69.2%), followed by MPP (10/19, 52.6%), and pattern 2 (12/23, 52.2%). CONCLUSION: MPP has comparable metastatic impact to the solid and the poorly formed acinar patterns and it is prognostically informative to document the presence or absence of the solid plus poorly formed glandular pattern > 50% and MPP > or = 20% when histological subtype is evaluated.

A comparative study of diagnostic tests for tuberculous lymphadenitis: polymerase chain reaction vs histopathology and clinical diagnosis.

UNLABELLED: To compare diagnostic tests for tuberculous lymphadenitis by polymerase chain reaction (PCR) with histopathology and clinical diagnosis in sensitivity, specificity and predictive value. This retrospective analytic, single blind study was done at King Chulalongkorn Memorial Hospital. Paraffin-embedded specimens were classified into 2 groups. The study group contained 30 proved AFB positive paraffin-embedded specimens from patients who also had clinical diagnosis of tuberculosis and improved by antituberculous treatment. The control group contained 30 formalin-fixed, paraffin-embedded specimens of lymph node hyperplasia proved by histopathological and clinical review. All 60 specimens were slided, and systematically labeled and sent to PCR lab. Polymerase Chain Reaction method had sensitivity = 43.33 per cent, specificity = 100 per cent, positive predictive value = 100 per cent and negative predictive value = 63.83 per cent. The present findings revealed that the PCR results were related to the age of the paraffin-embedded tissues. No positive results were obtained from tissues kept since 1996. Positive results were obtained in 3/7 cases (42.86%), 2/3 (66.67%) and 8/10 cases (80%) from tissue of 1997, 1998 and 1999 respectively. CONCLUSION: Polymerase chain reaction has sufficient reliability best as a confirmatory diagnostic test for tuberculous lymphadenitis; however, it is not appropriate as a screening test.

Noncrystallized form of immunoglobulin-storing histiocytosis as a cause of chronic lung infiltration in multiple myeloma.

A 52-year-old man, with a known case of multiple myeloma, developed chronic bilateral pulmonary infiltration. Open lung biopsy displayed desquamated interstitial pneumonia-like pattern characterized by diffused patchy intra-alveolar accumulation of unusual macrophages containing abundant round intracytoplasmic eosinophilic globular structures 1-7 microm in size. The globules were stained positively with restriction for kappa light chain by immunoperoxidase study. Electron microscopic examination revealed amorphous substances without a crystalline shape or fine ultrastructure of lattice or linear parallel configuration, indicating storage of noncrystallized immunoglobulin. The current report documented, for the first time, the noncrystallized form of immunoglobulin-storing histiocytosis, causing an unusual pulmonary pathology in a patient with multiple myeloma.

Systemic form of juvenile xanthogranuloma: report of a case with liver and bone marrow involvement.

Systemic form of juvenile xanthogranuloma with involvement of liver and bone marrow is reported in a 2-month-old female infant who presented with hepatosplenomegaly, severe anemia, and thrombocytopenia. There was no skin lesion, nor bone lesion. The enlarged liver has generalized yellowish spots. The diagnosis of juvenile xanthogranuloma was made by pathologic findings of marrow and portal tract infiltration by S-100 negative, CD1a negative, CD68 positive, and Factor XIIIa positive large pale to foamy histiocytes with Touton giant cells, and lack of Langerhans cell granule by electron microscopic examination. The patient was treated with Vinblastine and Etoposide, and experienced slow and gradual disease regression in one year. To the best of knowledge, this is the first documented case of bone marrow involvement in systemic juvenile xanthogranuloma.

Alveolar septal deposition of immunoglobulin and complement parallels pulmonary hemorrhage in a guinea pig model of severe pulmonary leptospirosis.

Human patients suffering from leptospirosis present with a diverse array of clinical manifestations, including the more severe and often fatal pulmonary form of the disease. The etiology of pulmonary hemorrhage is unclear. Isolates of Leptospira acquired from patients suffering from pulmonary hemorrhage were used to develop a guinea pig model of pulmonary hemorrhage. Gross findings post-infection confirmed extensive hemorrhage in the lungs and on peritoneal surfaces as the likely cause of death. Immunohistochemistry confirmed the presence of large numbers of leptospires in kidney, liver, intestinal tissues, and spleen, but few inflammatory cells were seen. In marked contrast, few leptospires were detected in infected hemorrhagic lung tissue. Blood chemistries and hematology did not reveal the etiology of the hemorrhage observed. There was no chemical or microscopic evidence for disseminated intravascular coagulation. To ascertain an immunopathologic role during disease, immunofluorescence was performed on infected lung tissues and confirmed the presence of IgM, IgG, IgA, and C3 along the alveolar basement membrane. This suggests that an autoimmune process may be the etiology of fatal pulmonary hemorrhage in leptospirosis.