Pulmonary IgG4+ Rosai-Dorfman disease

Rosai-Dorfman disease: an overview

CONTEXT

Rosai-Dorfman disease is an uncommon histiocytic disorder most frequently presenting as bilateral cervical lymphadenopathy in children and young adults. Extranodal disease occurs in a significant proportion of patients. It has been recently classified as part of the 'R group' of histiocytoses by the Histiocyte Society in 2016. Cutaneous Rosai-Dorfman disease is regarded as a separate disease entity that falls into the 'C group' of histiocytoses according to this classification system. The pathogenesis was previously poorly understood; however, recent evidence demonstrating clonality in a subset of cases raises the possibility of a neoplastic process. A possible association with IgG4-related disease remains controversial.

OBJECTIVES

To provide a comprehensive review of Rosai-Dorfman disease, including nodal, extranodal and cutaneous forms, with a particular emphasis on new insights into the possible clonal nature of the disease; to discuss the recently revised classification of the histiocytoses by the Histiocyte Society; and to summarise the findings from the literature regarding the controversial association with IgG4-related disease.

DATA SOURCES

This review is based on published peer-reviewed English literature.

CONCLUSIONS

Classic Rosai-Dorfman disease, which may be sporadic or familial, is considered a separate entity from cutaneous disease, which is reflected in the revised classification of histiocytoses. An increase in IgG4-positive plasma cells may be seen in Rosai-Dorfman disease. This finding in isolation is of limited significance and should be interpreted with caution. Studies investigating the molecular profile of the disease show that in at least a subset of cases the disease is a clonal process. The classification of Rosai-Dorfman disease is therefore likely to change as our understanding of the aetiopathogenesis evolves.

Rosai-Dorfman Disease of the Pancreas Shows Significant Histologic Overlap With IgG4-related Disease

Rosai-Dorfman disease (RDD) is a rare entity characterized by proliferating S100-positive histiocytes. Originally described in lymph nodes, it can involve extranodal sites. Pancreatic involvement is rare, with <10 cases previously reported. Recent studies demonstrate a possible overlap between RDD and the more common IgG4-related disease (IRD), which could further complicate pathologic diagnosis. We describe distinct morphologic characteristics as well as overlapping histologic features of IRD in 5 cases of pancreatic RDD at our institution and compare these to a cohort of nonpancreatic extranodal RDD cases. All pancreatic cases were mass forming and had spindled patterns of elongated histiocytes with smaller areas of more classical appearing RDD; all cases had areas of storiform fibrosis and dense lymphoplasmacytic infiltrates with no increase in IgG4-positive plasma cells, and all cases had some degree of vasculitis (4 cases had obliterative vasculitis). Thirteen nonpancreatic extranodal RDD cases had dense lymphoplasmacytic infiltrates; most (85%) had some fibrosis with 46% showing storiform fibrosis, 85% had vasculitis with 31% demonstrating obliterative vasculitis and 2 cases had increased IgG4 staining. Extranodal (pancreatic and nonpancreatic) RDD often shows overlapping morphologic features with IRD, including lymphoplasmacytic inflammation, storiform fibrosis with elongated histiocytes and vasculitis. This can create a diagnostic challenge in the pancreas where IRD is more commonly encountered. Pathologists need to be aware that RDD can occur in the pancreas and should include RDD in the differential of any mass forming pancreatic lesion in which morphologic features of IRD are present.

Histiocytosis masquerading in the mesentery and pleura

We present an atypical presentation of Rosai-Dorfman disease (RDD). Due to its overlap with IgG4-related disease (IgG4-RD), this case proved to be a diagnostic dilemma. Our case is an example of the importance of having a broad-based differential and, ultimately, an in-depth histopathological review. Our patient presented with a constellation of symptoms suggestive of an underlying malignancy. He was provisionally diagnosed with peritoneal carcinomatosis of an unknown primary. His initial presentation triggered a series of investigations, surgery and biopsies. Omental biopsy specimens were suggestive of IgG4-RD. Despite appropriate treatment for IgG4-RD, his disease progressed, specifically in the lungs. Pleural biopsies were then collected and assessed alongside the omental biopsies. On review and reassessment, the patient was formally diagnosed with RDD.

Fine-needle aspiration specimens of 3 cases of intra-abdominal Rosai-Dorfman disease with comprehensive review of the literature

INTRODUCTION

Rosai-Dorfman disease (RDD) is a rare usually self-limited non-Langerhans cell histiocytosis of unknown etiology. Nodal and extranodal RDD appear to represent distinct conditions with different molecular alterations and prognosis. They also pose different diagnostic challenges on biopsies and fine-needle aspiration (FNA) cytology. The aim of this study was to report on 3 cases of intra-abdominal RDD and perform an extensive review of the literature on FNA findings of RDD.

MATERIALS AND METHODS

We reviewed FNA specimens from cases diagnosed histologically or cytologically as RDD during the past 10 years. We searched the PubMed and Google Scholar databases for cases of RDD sampled by FNA.

RESULTS

We identified 3 cases of intra-abdominal RDD, involving the kidney, periportal lymph node, and pancreas. FNA of the latter was hypocellular with fibrosis and was nondiagnostic. FNA of the first 2 yielded hypercellular smears that were diagnosed as RDD due to the identification of emperipolesis occurring in large uni- or binucleated histiocytes with large nuclei, fine chromatin, and prominent nucleoli in smears and cell-block sections. Immunohistochemistry showed positive staining for S100 and CD68 and negative staining for CD1a. The large histiocytes with emperipolesis were more difficult to identify histologically and their demonstration required immunohistochemical stains.

CONCLUSION

Our experience and an extensive review of the literature suggest that extranodal RDD can be diagnosed on FNA, and that the recognition of histiocytes with emperipolesis may be less challenging cytologically than histologically. The fibrosis frequently seen in extranodal RDD may lead to nondiagnostic aspirates, however.

[Solitary epithelioid hemangioendothelioma concurrent with nodular parenchymal amyloidosis of the lung and Rosai-Dorfman disease]

The paper describes a case of solitary epithelioid hemangioendothelioma concurrent with nodular parenchymal AL amyloidosis of the lung and Rosai-Dorfman disease in a 70-year-old woman. The core of the tumor was represented by bone tissue with dendriform ossification, as well as by amyloid that showed green apple birefringence at polarized light microscopy. The peripheral portions of the tumor and the myxohyaline stroma exhibited slit-like structures, epithelioid and fusiform cells with small cytoplasmic vacuoles. These cells expressed CD31, CD34, factor VIII, and cytokeratins 7 and 18. The Ki-67 proliferation index was 10%. S100- and CD68-positive histiocytes with the phenomenon of emperipolesis were revealed in the tumor and in the lymph nodes of the mediastinum and lung hilum. There was a positive reaction to immunoglobulin lambda light chains in the lymphocytic infiltration around amyloid clumps. The frequency of epithelioid hemangioendothelioma was less than 1 case per million people annually. We found only one case of its concurrence with pulmonary amyloidosis in the English-language literature. No relationship could be revealed between this tumor and Rosai-Dorfman disease.

IgG4-related skin disease may have distinct systemic manifestations: a systematic review

IgG4-related disease (IgG4-RD) is an increasingly prevalent protean multisystem disorder characterized by single or multi-organ infiltration of IgG4-bearing plasma cells. Skin involvement has been recognized and is relevant to proper diagnosis. A systematic literature review of 50 cases involving the skin reveals that patients with IgG4-related skin disease show predominant involvement of the head and neck and have a distinct pattern of systemic involvement, also favoring the head and neck - lymphatics, orbit, salivary, and lacrimal glands - but generally lacking pancreaticobiliary involvement (16% of cases), which by contrast is a predominant manifestation in systemic IgG4-RD (60% with pancreaticobiliary involvement). We summarize clinical and pathologic descriptive data from this systematic review. We review differential diagnosis and propose a diagnostic scheme for stratifying probability of disease based upon comprehensive integration of clinical, histopathologic, and laboratory data. Plasmacyte infiltration and storiform fibrosis are prominent in IgG4-related skin disease, but obliterative venulitis is less common than in the prototypical IgG4-related disease manifestation of autoimmune pancreatitis. IgG4 tissue and serum values, with a mean (±95% CI) in the reviewed cases of 132.8 ± 32.6 IgG4-positive plasma cells per high-power field and 580 ± 183.8 mg/dl, respectively, are incorporated into the suggested criteria. The distinct set of manifestations identified by this systematic review and the proposed diagnostic considerations, while requiring further validation in prospective studies, highlight the need to consider that IgG4-related skin disease defines a unique systemic disease complex along the spectrum of IgG4-RD.

Rosai-Dorfman Disease of the Lung Overlapping with IgG4-related Disease: The Difficulty in Its Differential Diagnosis

We herein report a case of Rosai-Dorfman disease (RDD) overlapping with IgG4-related disease (IgG4-RD), which presented as diffuse interstitial lung disease with a perilymphatic pattern, followed by submandibular gland and eyelid swelling. The pathological findings of the submandibular gland biopsy specimen were indicative of IgG4-RD alone. We diagnosed the patient with RDD with overlapping IgG4-RD. However, the optimal method for differentiating between these two entities is still controversial. It is important that clinicians are aware that RDD should be included in the differential diagnoses of diffuse interstitial lung disease with a perilymphatic pattern and that RDD can overlap with IgG4-RD.

Adult-Onset Asthma and Periocular Xanthogranulomas Associated with Systemic IgG4-Related Disease

PURPOSE

The aim of this study was to report a case of Adult-Onset Asthma with Periocular Xanthogranulomas (AAPOX) associated with systemic IgG4-related disease (IgG4-RD).

OBSERVATIONS

A 57-year-old man presented with bilateral periorbital swelling for 1 year. Histopathology of a left orbital biopsy showed fibro vascular connective tissue inundated with foamy, lipid-laden histiocytes and touton giant cells with lymphocytic inflammation. Additional stains revealed CD68 positivity, and S100 negativity. The IgG and IgG4 stained slides showed increased IgG4 positive plasma cells but did not meet the criteria for IgG4-related orbital disease. His IgG4 serology was elevated, and IgG4 staining of his tissue previously diagnosed as autoimmune sclerosing pancreatitis was found to meet the criteria for IgG4-RD.

CONCLUSIONS AND IMPORTANCE

AAPOX can be associated with systemic IgG4-RD.