Incidental Histologic Finding Research Articles

Mammary Schistosomiasis: Malignancy Mimicker or More?

Abstract Introduction/Objective Schistosomiasis is a neglected tropical disease (NTD) which affects more than 200 million people worldwide, with approximately 85% of cases occurring in sub-Saharan Africa. It serves both as an important etiologic agent in the development of carcinomas of many organ systems, as well as a common incidental histological finding in various organs, including the prostate, lung, spine, and liver. Detection of Schistosoma ova in the breast is rare. Here, we present a case of schistosomiasis of the breast in a patient concurrently diagnosed with breast carcinoma of the contralateral breast. Methods/Case Report A 48-year-old Mozambican female presented with a right breast mass, with suspicious microcalcifications detected in the contralateral breast on mammography. Biopsy confirmed invasive ductal carcinoma of no special type (NST) in the right breast and identified Schistosoma ova in the left, notably lacking an associated inflammatory response. A Ziehl-Neelsen special histochemical stain was negative, favoring schistosoma Hematobium species. Results (if a Case Study enter NA) NA Conclusion Our case marks the first in English literature where schistosomiasis was identified in the context of contralateral breast carcinoma, posing the question as to whether there is an association between schistosomiasis and breast carcinoma in our patient. One possible theory suggests hyperestrogenism secondary to Schistosoma infection in the liver. Breast schistosomiasis presenting as microcalcifications poses a diagnostic challenge, as it may clinically and radiologically resemble malignant breast disease. Histopathological diagnosis is crucial to confirm the diagnosis and prevent unnecessary procedures. Contrary to other organ systems, our case highlighted that schistosomiasis in the breast may not be accompanied by any inflammatory response. Definitive conclusions regarding the exact species of schistosomiasis cannot be drawn histologically based solely on H&E findings due to the plane of sectioning; therefore, performing a Ziehl-Neelsen stain is beneficial. As screening mammography increases in endemic areas, a high index of suspicion and further research is warranted.

Langerhans Cell Histiocytosis Associated With Renal Cell Carcinoma Is a Neoplastic Process: Clinicopathologic and Molecular Study of 7 Cases.

Langerhans cell histiocytosis (LCH) is a rare histiocytic disorder composed of Langerhans cells admixed with reactive mononuclear and granulocytic cells, associated with prominent eosinophils. LCH is considered a neoplasm, driven in most cases by oncogenic RAS/RAF/MEK/ERK pathway mutations. The disease predominantly affects children. Urinary system involvement has rarely been reported in a multisystem disease setting. We describe 7 patients who presented with LCH occurring within (6 cases) or after (1 case) a resected clear cell (n=6) or clear cell papillary (n=1) renal cell carcinoma (RCC), identified prospectively in our routine and consultation files (2012 to 2019). The patients included 5 women and 2 men, with a median age of 54 years (range, 39 to 73 y), none with a history of LCH or LCH manifestations before the time of RCC diagnosis. The median size of the RCC was 3.5 cm (range, 1.8 to 8.3 cm). Treatment included partial (5 cases), or radical (2 cases) nephrectomy. All RCCs on gross examination showed at least focal cystic changes and were low grade (World Health Organization [WHO]/International Society of Urologic Pathologists [ISUP] grade 1 to 2). The LCH foci were detected as incidental histological finding within the resected RCC in all six cases and they were limited to few high-power fields (<2 mm) in 5 of 6 cases, but in the sixth case, they occupied almost the entire clear cell papillary RCC (2 cm nodule). No LCH manifestations were detected in the normal kidney or in perinephric fat. The seventh patient developed LCH within inguinal deep soft tissue followed by systemic manifestations 6 years after clear cell RCC. Langerhans cell immunophenotype was supported by the reactivity for S-100, CD1a, and langerin and by the negative pankeratin. Successful pyrosequencing of microdissected LCH DNA revealed the V600E BRAF mutation in all 6 cases of LCH within RCC. To our knowledge, only 3 similar cases were published since 1980; the only case tested for BRAF mutation showed wild-type BRAF. This is the first study analyzing the morphologic and genetic features of a cohort of LCH associated with RCC. In our experience, these cases may be underrecognized in practice, or may erroneously be diagnosed as RCC dedifferentiation or high-grade sarcomatoid transformation. Finally, the detection of BRAF mutation further confirms that LCH in this setting is indeed a neoplasm, rather than a reactive lesion.

Isolated eosinophilic myometritis –A rare histological finding

Isolated eosinophilic myometritis –A rare histological finding - JDPO- Print ISSN No: - 2581-3714 Online ISSN No:- 2581-3706 Article DOI No:- 10.18231/j.jdpo.2019.047, IP Journal of Diagnostic Pathology and Oncology-IP J Diagn Pathol Oncol

Incidental splenic findings in pancreatosplenectomy specimens resected for primary pancreatic lesions.

Little has been written on the frequency and nature of incidental splenic lesions diagnosed on histopathological examination of pancreatosplenectomy specimens. For 191 such specimens, incidental histological findings after haematopathologist re-review were tabulated. Cases suspicious for lymphoid malignancy underwent molecular analysis for immunoglobulin heavy and kappa light chain rearrangement. Follow-up was obtained on selected cases. In five cases (3%), the spleen was sampled but not mentioned in the original microscopic report; all were normal on re-review. Otherwise, most (171 of 186, 92%) were initially diagnosed as normal, with 160 (94%) remaining so on re-review. Findings on re-review not initially described (n=11, 6%) included four cases with splenic morphology suspicious for possible leukaemia/lymphoma involvement. Additional findings included abscess formation, foamy macrophages, necrotising granulomas and simple cysts. Fifteen spleens were initially diagnosed as abnormal; the histopathological process was confirmed in all, including non-necrotising granulomas, cysts, Gamna-Gandy bodies, foamy macrophages, involvement by pancreatic neoplasm and involvement by known chronic lymphocytic leukaemia (CLL). Molecular analysis was performed on the five cases of known/suspected lymphoma and two were positive for monoclonal gene rearrangement, including the known CLL and a previously undiagnosed case with similar immunophenotype. Incidental splenic findings are not uncommon in pancreatosplenectomy specimens. While most are of limited clinical significance, low-grade lymphoproliferative disorders may go undetected if the spleen is overlooked. We recommend careful observation of splenic findings in these specimens, with a low threshold for haematopathological consultation when in doubt.

Prevalence of Histologically Proven Acute Appendicitis and Incidental Carcinoid Tumour in the Practice of Surgical Pathology at BPKIHS

Background: Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. &#x0D; Objectives: To determine the relative prevalence of histologically proven acute appendicitis in surgically resected specimens with clinical diagnosis of acute appendicitis and to find out the rate of occurrence of carcinoid tumour as an incidental histologic finding. &#x0D; Methods: &#x0D; Type of study- descriptive study &#x0D; Study unit- all gross specimens received in the department of pathology over a period of twenty months (1.1.2006 to 31.8.2007) &#x0D; Study sample- Histologic data on 515 appendicectomy samples (clinically diagnosed as appendicitis) of the total 7295 specimens received over a period of twenty months were retrieved from the archives of department of pathology, B. P. Koirala Institute of Health Sciences (BPKIHS). &#x0D; Exclusion criteria- appendectomy incidental to another surgical procedure. &#x0D; Results: Appendectomy specimens constituted 7.0% (n= 515; M:F 1.1:1) of all surgical pathologic specimens (n= 7295) at BPKIHS. Following is the breakup of histologic diagnosis: acute appendicitis with or without periappendicitis and gangrenous change (93.6%, n= 482), receding appendicitis (5.4%, n= 28), normal histology (1.0%, n= 5). Carcinoid tumours were detected incidentally in three cases (0.58%) out of the total number of 515 appendectomy specimens. &#x0D; Conclusion: Analysis of data revealed &#x0D; &#x0D; A relatively higher prevalence (6.99%) of histologically proven acute appendicitis in this Tertiary health care set up compared to similar data reported in the literature. &#x0D; Rate of occurrence (0.58%) of carcinoid tumour as incidental finding is similar to that reported in the literature.&#x0D;

Abstract P1-01-10: Pleomorphic lobular carcinoma in situ (PLCIS)-presentation, associated lesions and outcome

Abstract Pleomorphic lobular carcinoma in situ (PLCIS) is an uncommon lesion characterised by dyscohesive lobular cells showing high grade nuclei. It is commonly associated with comedo necrosis and luminal calcifications and hence diagnosed on mammographic screening. Data on the presentation, focality, associated lesions, optimal treatment and outcome of PLCIS is patchy. Methods Cases diagnosed as PLCIS between 2005 and 2015 were identified from the imaging and pathology databases of two UK large breast screening units. Cases diagnosed on diagnostic core biopsy/VAB or surgical excisions were included. Comprehensive data was collected on age, mode of presentation (screening vs symptomatic), imaging (mammography, ultrasound and MRI), surgical management, histological features on core biopsy and excision including type, grade and immunohistochemical profile of associated ductal carcinoma in situ (DCIS) and invasive carcinoma. Results 86 cases with the diagnosis of PLCIS (confirmed by review and e-cadherin negativity) were identified. The mean patient age at diagnosis was 61.04 years, range: 39-84 years. 32 cases were treated with wide local excision with/without axillary procedure. A total of 38 patients were screen detected &amp; 36 cases were diagnosed in the symptomatic setting. Others presented as incidental calcifications on family history screening, incidental histological findings in breast reductions and risk reducing mastectomy. On mammography, 6 patients presented with an asymmetrical density, with or without calcifications, 25 with calcifications, 44 as a mass and 2 as stromal deformity. No mammographic abnormality was found in 9 cases. PLCIS was multifocal in 19.7% of cases, diffuse in 9.9%, focal in 69% and multi-centric in 1.4% on imaging. Histologically, PLCIS was the most advanced lesion on core biopsy without associated DCIS or invasive disease (pure PLCIS) in 23 patients. Of these, surgical excision revealed an invasive carcinoma in 7 cases (upgrade rate =30.4%). Six more patients presented as DCIS and PLCIS on core biopsy; three of whom (50%) had invasive disease on excision. Classical LCIS was associated with PLCIS in 27/86 cases (31.3%). The most common type of associated invasive carcinoma on surgical excision was invasive classical lobular carcinoma (ILC, 40 cases), followed by invasive pleomorphic lobular carcinoma (IPLC, 27 cases). Ductal no special type carcinoma, solid papillary and tubulo-lobular carcinoma were also identified. The size of PLCIS on excision ranged from 1-80mm. DCIS was associated in 26.7% of cases. The majority of invasive cancers were of grade 2 (53.5%) and 3 (19%). The tumors were ER positive (53 cases), PR positive (43 cases) and HER2 negative (52 cases). Conclusion PLCIS is an uncommon in situ carcinoma presenting via mammographic and also in the symptomatic setting. Unlike classical LCIS, PLCIS is a disease of postmenopausal women. It is multifocal in approximately one fifth of the cases. PLCIS is commonly associated with classical LCIS and both ILC and IPLC. When identified in core biopsy, the upgrade rate in this series was 30.4% which increased to 50% if the lesion co-existed with DCIS. The associated cancers are often ER positive, HER2 negative. These findings support managing those lesions surgically as per DCIS. Citation Format: Shaaban AM, Smith S, Bradley S, McMahon M, Sharma N. Pleomorphic lobular carcinoma in situ (PLCIS)-presentation, associated lesions and outcome. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-01-10.

Low-grade adenosquamous carcinoma of the breast: A diagnostic and clinical challenge

Adenosquamous carcinoma of the breast (ASBC) is a rare variant of metaplastic breast cancer with both glandular as well as squamous differentiation. Their lack of distinct imaging characteristics, sometimes subtle histological characteristics and overlapping features with other benign lesions pose a diagnostic challenge. Unlike other forms of metaplastic breast cancer, low-grade adenosquamous carcinoma (LGAC) tends to follow an indolent course with favourable prognosis. We reviewed eight cases of LGAC in our institution from June 2005 to March 2014. In six cases, LGAC was only found after excisional biopsy. In our patients, LGAC frequently co-existed with other forms of breast pathology. Two patients had incidental findings of LGAC alongside their primary malignant tumour (adenoid cystic carcinoma and invasive ductal carcinoma in one, four foci between 0.5 and 4.0 mm within a radial sclerosing lesion adjacent to a malignant phyllodes tumour in the other). A further four patients had LGAC within a complex sclerosing lesion. One patient had a focus of LGAC within a fibroadenoma. One had a focus of LGAC within a benign phyllodes tumour. None of the patients had evidence of nodal involvement. A high degree of suspicion is recommended as such lesions tend to be incidental histological findings within benign tumours or within complex sclerosing lesions. Although the risk of nodal and distant metastasis is low, the potential for local recurrence necessitates aggressive local excision with margin clearance. The role of axillary dissection has yet to be defined and routine sentinel node biopsy and axillary clearance may not be necessary in view of rarity of nodal metastasis in literature. Benefit from adjuvant radiotherapy or chemotherapy is not clearly defined. All eight patients in our study have shown no evidence of recurrence after definitive surgery but longer periods of surveillance is required.

Apport de l’histopathologie dans le diagnostic d’une calcinose scrotale: a propos d’un cas

Scrotal calcinosis is a rare, benign condition of uncertain pathogenesis characterized by multiple painless, hard lumps in the scrotum, without any systemic metabolic disorder. We report on the case of a patient aged 57 years who presented with scrotal calcinosis as an incidental histological finding associated with chronic eczema and a left inguinal hernia. We discuss, after reviewing the literature, the pathogenic, clinical, therapeutic, and pathologic aspects of this poorly understood condition.

Predictive factors for incidental gallbladder dysplasia and carcinoma

BackgroundThis study aims to analyze clinical characteristics and demographics of all patients admitted for cholecystectomy in a tertiary referral center to determine predictors of incidental gallbladder dysplasia (IGBD) and incidental gallbladder carcinoma (IGBC). MethodsA retrospective analyses of clinical, demographic, and histologic features of patients undergoing cholecystectomy in a single tertiary institution from 2005–2012 were performed using a logistic regression model to determine the predictors of IGBD and IGBC. ResultsSome 771 (28 conversions to open surgery [3.6%]) and 93 patients (10.7%) underwent laparoscopic and open cholecystectomies for gallstone disease, respectively. At final pathology, IGBD (low-grade [n = 10], high-grade [n = 2], mixed-grade [n = 1], and adenoma-associated [n = 5] dysplasia) was found in 18 patients (2%; median age, 45 y; interquartile range, 42.5–63.5; male-to-female ratio, 1:2; six Caucasian; and 12 Asian). IGBC was found in seven patients (0.8%; median age, 69 y; interquartile range, 69–72; one Afro-Caribbean; four Caucasian; and two Asian). Logistic regression analysis revealed Asian patients to be at a higher risk of IGBD (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.1–8.0; P = 0.02). Only age (OR, 1.12; 95% CI, 1.04–1.2; P < 0.01) and polypoid lesions (OR, 37.4; 95% CI, 2.97–470.6; P = 0.01) were significantly associated with IGBC. Receiver operating characteristic curve analysis demonstrated that age >68 y correlated positively to IGBC. ConclusionsIGBD and IGBC are fairly common incidental histologic finding after cholecystectomy for gallstone disease. When considering cholecystectomy, patients' demographics, in particular age and race, should always be considered as this might help the surgeon and the pathologist to institute the appropriate treatment.

Characteristics of Patients With Advanced Heart Failure Having Eosinophilic Infiltration of the Myocardium in the Recent Era

Eosinophilic infiltration of the myocardium is occasionally observed as an incidental histological finding in endomyocardial biopsy specimens before heart transplantation (HTx) as well as in explanted heart obtained at the time of HTx. However, the indications for HTx in these patients have not yet been fully established. We investigated the pre-HTx characteristics of the recipients with myocardial eosinophilic infiltration in the explanted heart and diagnosed as hypersensitivity myocarditis (HSM) (21 among 761 recipients, 2.8%). Dobutamine, a common cause of HSM, was administered to 12 patients (57%). Ten patients (47.6%) were on milrinone and 4 (19.0%) were on ventricular assist devices. Post-transplant survival of HSM patients was comparable to that of patients transplanted for active myocarditis or other cause of heart failure. In conclusion, myocardial eosinophilic infiltration is associated with multiple medications in patients with advanced heart failure; however, it does not affect the post-transplant prognosis.

Hiperplasia estromal pseudoangiomatosa de la mama (HEPA): estudio clínico, radiológico y patológico de 4 casos

Pseudoangiomatous stromal hyperplasia (PASH) is a rare benign breast lesion, characterized by a benign overgrowth of fibrous connective tissue of the breast, which produces numerous spaces resembling vascular structures. This entity most commonly affects premenopausal women but cases have been described at all ages ranging from 12 to 75 years. PASH is usually an incidental histological finding after surgery for benign or malignant tumors but may also present as a mass or painless nodule mimicking fibroadenoma. Ultrasound-guided percutaneous biopsy allows the type of lesion to be determined and malignancies, such as low-grade angiosarcoma, to be excluded. We report four new cases of PASH with distinct clinical presentations. The first two cases presented as a single painless breast mass, the third as an incidental finding in the surgical specimen from a quadrantectomy performed for an intraductal breast carcinoma, and the fourth case occurred in a man with unilateral gynecomastia.

Expression of estrogen and androgen receptors in differentiated thyroid cancer: an additional criterion to assess the patient's risk

Estrogen receptor (ER) and androgen receptor (AR) may be expressed in thyroid tumors, but their prognostic role is controversial. We investigated whether ER and AR expressions could confer a more aggressive phenotype to thyroid tumors. We enrolled 91 patients (13 males and 78 females, mean age 49.3±14.8 years) bearing small (T1 in the 2006 TNM system) differentiated thyroid cancers (DTC). Thirty-eight tumors were incidental histological findings. Using immunohistochemistry, we evaluated ERα, ERβ, and AR expressions in tumors and in its correspondent extra-tumor parenchyma. In tumors, 13 (16.7%) women and one (7.7%) man expressed ERα; 42 (53.8%) women and six (46%) men expressed ERβ; and 16 (20.5%) women and three (23.1%) men expressed AR. In normal thyroid parenchymas, ERβ was expressed in 52 (66.7%) women and nine (69.2%) men, ERα in three (3.8%) women, and AR in 13 (16.7%) women. Compared with normal thyroid parenchyma, tumors gained ERα and lost ERβ expressions. Incidental cancers were more commonly ERα(-) than ERα(+) (47.7 vs 14.3%, P=0.037). Postsurgical serum thyroglobulin was higher in ERα(+) tumors than in the ERα(-) tumors (P=0.04). ERβ(-) tumors showed vascular invasion more frequently than the ERβ(+) tumors (26.2 vs 4.1%, P=0.005). AR(+) tumors showed capsular invasion more frequently than the AR(-) tumors (77.8 vs 46.6%, P=0.014). In conclusion, ERα positivity, ERβ negativity, and AR expressions are associated with a more aggressive phenotype of small T1-DTC. ER and AR expressions may represent an additional criterion in deciding whether to perform radioiodine ablation in these tumors.

Mesenteric paraganglioma with gallbladder paraganglion nest.

We report on an original case of a 64 year old lady diagnosed with an extraadrenal mesenteric paraganglioma associated with an incidental histological finding of a gallbladder paraganglion. Paragangliomas are rare neuroendocrine, neural crest-derived tumours, found in diverse locations and display variable catecholamine secreting behaviour. Malignant potential can be difficult to predict on histology. We review the current literature on these multifarious tumours.

Pseudoangiomatous Stromal Hyperplasia: An Overview

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a benign, proliferative mesenchymal lesion with possible hormonal etiology. It typically affects women in the reproductive age group. Pseudoangiomatous stromal hyperplasia is frequently an incidental histologic finding in breast biopsies performed for other benign or malignant lesions. Rarely, it can present as a firm, painless breast mass, which has been referred to as nodular or tumorous PASH. Grossly, tumorous PASH is a well-circumscribed, firm, rubbery mass with solid, homogenous, gray-white cut surface. On histologic examination, it is characterized by the presence of open slitlike spaces in dense collagenous stroma. The spaces are lined by a discontinuous layer of flat, spindle-shaped myofibroblasts with bland nuclei. The spindle cells express progesterone receptors and are positive for vimentin, actin, and CD34. The most important differential diagnosis on histopathology is angiosarcoma. Pseudoangiomatous stromal hyperplasia discovered incidentally does not require any additional specific treatment. Tumorous PASH is treated by local surgical excision with clear margins and the prognosis is excellent, with minimal risk of recurrence after adequate surgical excision.

Pagetoid dyskeratosis: a frequent pitfall in dermatopathology

Auteur(s) : Jean Kanitakis, Viviana Lora Lab. of Dermatopathology, Ed. Herriot Hospital, 69437 Lyon cedex 03, Lyon, France Pagetoid dyskeratosis (PD) is an incidental histologic finding that can be observed in skin biopsies from various lesions, including acrochordons [1]. PD has been observed in various locations, such as the hand [2], lips [3], prepuce [4] and nipple [5]. PD cells are keratinocytes with a larger size than normal, usually a round shape, a pale cytoplasm and a pycnotic nucleus surrounded [...]

Paget's Disease of the Nipple

Paget's disease of the nipple is an unusual epidermal presentation of underlying breast cancer. It presents as eczematous change or erythematous ulceration, but may also be an incidental histological finding in a mastectomy specimen. Approximately half of the underlying cancers are invasive, the remainder being ductal carcinoma in situ, and only rarely is there no associated malignancy. Routine clinical and mammographic assessment may significantly underestimate the extent of disease, but MRI may increase the sensitivity in detecting occult malignancy. Mastectomy maximizes local control; however, selected cases can be treated by nipple conisation with radiotherapy. Sentinel node biopsy is the standard of care for axillary staging in the clinically and ultrasonically node-negative case. Almost all invasive cases overexpress human EGF receptor-2 and, therefore, are likely to benefit from adjuvant chemotherapy and herceptin.

Ectopic decidual reaction mimicking peritoneal tubercles: A report of three cases

Ectopic decidual reaction is commonly seen in the ovary and cervix; however, peritoneal localization is rare. Peritoneal deciduosis is usually an incidental histological finding. It may present a diagnostic dilemma by mimicking grossly peritoneal carcinomatosis or tubercles and deciduoid mesothelioma, microscopically. We report three cases of ectopic decidual reaction discovered incidentally during caesarian sections, as whitish yellow nodules resembling tubercles. Histology revealed extensive decidualisation. To the best of our knowledge, this is the first report of ectopic decidua mimicking peritoneal tubercles.

Routine surgical pathology in general surgery

Although pathological analysis provides the definitive diagnosis for most resection specimens, recent evidence suggests that such analysis may be omitted for certain routine samples. This was a retrospective analysis of the value of routine histopathological examination performed in daily general surgical practice. All specimens from routine appendicectomies, cholecystectomies, haemorrhoidectomies and inguinal hernia repairs performed between 1993 and 2002 were included. The analysis included a comparison of histological and macroscopic diagnoses, review of preoperative and peroperative findings, and an evaluation of the consequences of routine histopathological assessment on patient management and costs. With the exception of hernia specimens, the rate of submission for routine pathological evaluation was 100 per cent. No hernia sac specimen from more than 2000 interventions revealed aberrant histological findings. Of 311 haemorrhoidectomy specimens three showed malignancy, all of which had a suspicious macroscopic appearance. Of 1465 appendices, only one (0.1 per cent) had a potentially relevant histological diagnosis that was not suspected macroscopically. Among 1523 cholecystectomy specimens, all adenomas (0.6 per cent) and carcinomas (0.4 per cent) were suspected macroscopically or developed in association with a known disease. The rarity of incidental histological findings relevant to patient management, especially in the absence of macroscopic abnormalities, suggests that routine histological examination of certain specimens may be omitted. A more elementary role for macroscopic examination of the specimen by the surgeon and the pathologist is proposed.

A Review of Respiratory Bronchiolitis and Respiratory Bronchiolitis-Associated Interstitial Lung Disease

In Brief Respiratory bronchiolitis (RB) and respiratory bronchiolitis–associated interstitial lung disease (RB-ILD) are 2 processes that lie along the continuum of probable smoking related lung diseases. The separation of the 2 is difficult and sometimes contentious; however, the combination of clinical symptoms and suggestive pathologic findings usually allows for a distinction and the subsequent diagnosis. RB in an asymptomatic smoker is considered an incidental histologic finding consistent with prior tobacco history. RB-ILD, although histopathologically similar to RB, is characterized by more extensive pulmonary parenchymal involvement and clinical expression as defined by dyspnea or other respiratory complaints. On pulmonary function testing, RB-ILD patients often demonstrate a mixed picture of obstructive or restrictive physiology, in combination with a reduced carbon monoxide diffusion capacity. Plain chest radiography is of limited utility and can be normal in many RB-ILD patients. High-resolution computer-assisted tomography scanning in the setting of RB-ILD correlates with the extent of bronchiolitis on pathologic analysis and offers a potential role for assessing response to therapy. Thus far, bronchoscopy has demonstrated a relatively limited capacity in diagnosing RB-ILD, necessitating surgical lung biopsy to arrive at a definitive diagnosis. Treatment of RB-ILD hinges upon smoking cessation maneuvers and consideration of immunosuppressive agents in recalcitrant cases. Respiratory bronchiolitis and respiratory bronchiolitis–associated interstitial lung disease are two processes that lie along the continuum of probable tobacco smoking–imparted changes on the lung. The separation of the 2 is difficult and sometimes contentious. The combination of the presence of clinical symptoms in conjunction with suggestive pathologic findings usually allows for a distinction and the subsequent diagnosis.

Sinus Histiocytosis with Massive Lymphadenopathy and Malignant Lymphoma Involving the Same Lymph Node: A Report of Four Cases and Review of the Literature

Sinus histiocytosis with massive lymphadenopathy (SHML), also known as Rosai-Dorfman disease, is a disorder of unknown cause. Rarely, patients with SHML also have malignant lymphoma, usually involving anatomic sites different from those involved by SHML. We report four patients in whom SHML and malignant lymphoma were identified in the same lymph node biopsy specimen. The SHML in each case was present as a small focus, less than 1 cm. Immunohistochemical studies showed that the abnormal histiocytes were positive for S-100 and negative for CD1a. The malignant lymphomas included two cases of follicular lymphoma and two cases of Hodgkin's disease, nodular lymphocyte predominant type. The presence of SHML in these patients did not impact clinical decisions, and there was no evidence of SHML elsewhere. Thus, the presence of focal SHML associated with malignant lymphoma in these cases was an incidental histologic finding that seems not to have had any clinical significance.