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Radiol Case Rep
Radiol Case Rep
Radiology Case Reports
1930-0433
Elsevier

S1930-0433(24)00667-8
10.1016/j.radcr.2024.07.078
Case Report
Rosai-Dorfman disease presenting as a perirectal mass: A case report and review of diagnostic challenges
Adair Luther B. II MD luther.adair@nashvilleradiologypartners.com

Nashville Radiology Partners, 304 S. Jones Blvd. Unit 4377, Las Vegas, NV 89107, USA
12 8 2024
11 2024
12 8 2024
19 11 48094813
21 6 2024
13 7 2024
15 7 2024
© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.
2024

https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
An uncommon benign histiocytic illness, Rosai-Dorfman disease (RDD) mostly affects lymph nodes but can also manifest as extranodal involvement. We describe a case of a female patient, sixty years of age, who had joint discomfort, sleeplessness, weight loss, and headache and eye problems. A heterogeneously hypodense perirectal mass was seen on imaging. Other histiocytic diseases, metastatic cancer, and lymphoma were among the differential diagnosis. Through biopsy and immunohistochemistry staining, which revealed S-100 and CD68 positivity with CD1a negative, a definitive diagnosis of RDD was made. Over a 2-year period following surgical excision, the patient's symptoms significantly improved and there was no sign of recurrence. This example emphasizes the significance of taking RDD into account when making a differential diagnosis for perirectal tumors and the function of imaging in conjunction with histological testing in guiding management.

Keywords

Computed tomography
Rosai-Dorfman disease
Langerhans cell histiocytosis
Erdheim-Chester disease
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pmcIntroduction

A sixty-year-old female African American patient complained of joint discomfort, headache and eye pain, weight loss, and exhaustion. A differential diagnosis of lymphoma, metastatic carcinoma/recurrence of malignancy in the context of a known history of colon cancer, and other histiocytic disorders like Langerhans cell histiocytosis (LCH), Erdheim- Chester disease (ECD), and Rosai-Dorfman disease (RDD) was made after initial imaging revealed an irregular, heterogeneously hypodense perirectal mass. RDD was confirmed as the final diagnosis by histological analysis and immunohistochemistry staining of the biopsy sample [1]. Imaging was, however, helpful in evaluating the mass's behavior over time and ruling out other possible explanations, such as a malignancy return in the context of a known colon cancer history.

Case presentation

Rosai and Dorfman first reported Rosai-Dorfman illness, also called sinus histiocytosis with large lymphadenopathy, as an uncommon histiocytic disorder in 1969. Though it can also affect extranodal locations such the skin, soft tissues, respiratory tract, and central nervous system, lymph nodes are the primary target. Because extranodal involvement in the abdomen and pelvis is extremely uncommon, diagnosing it can be difficult because of imaging features that might be mistaken for other cancers [2].

The patient had a lengthy medical history, which included a hemicolectomy in February 2007 for colon cancer. For example, repeated perineal boils were treated with over-the-counter medications at first, and an anal fistula was later evaluated. The perirectal mass was assessed by a number of imaging tests and biopsies.

The imaging studies of this sixty-year-old female patient, conducted on multiple dates, revealed a stable right perirectal mass, consistent with Rosai-Dorfman disease (RDD). On December 21, 2021, MRI showed an abnormal signal intensity in the perirectal fat with enhancement, measuring approximately 3.9 × 2.5 cm (Figs. 1A-C). Follow-up MRI on September 12, 2022, demonstrated a stable T1/T2 hypointense enhancing ovoid nodule in the right mesorectal fat, measuring 1.8 × 1.1 cm, with mildly improved hazy stranding and a smaller perirectal nodule inferiorly (Fig. 2). A CT-guided biopsy on December 27, 2022, described the mass as heterogeneously hypodense with areas of low density and calcification (Fig. 3). The subsequent MRI on December 22, 2023, confirmed the stability of the right perirectal nodule with no new or enlarging pelvic mass or lymphadenopathy (Figs. 4A and B). The patient's symptoms and imaging findings, combined with histopathological and immunohistochemical analysis, led to the diagnosis of Rosai-Dorfman disease.Fig. 1 (A) T2 MRI of the pelvis: Initial MRI of the abdomen and pelvis in 2021 showed an inflammatory lesion in the right mesorectum, likely representing an infectious or inflammatory process (white arrows). (B) T1 MRI of the pelvis including fat saturation: Initial MRI of the abdomen and pelvis in 2021 showed an inflammatory lesion in the right mesorectum, likely representing an infectious or inflammatory process (white arrows).

(C) T1 MRI of the pelvis including intravenous contrast: Initial MRI of the abdomen and pelvis in 2021 showed an inflammatory lesion in the right mesorectum, likely representing an infectious or inflammatory process (white arrows).

Fig 1

Fig. 2 T1 MRI of the pelvis including intravenous contrast and fat saturation: MRI pelvis in 2022 revealed a stable T1/T2 hypointense enhancing ovoid nodular mass in the right mesorectal fat, consistent with the findings from December 2021 (white arrows).

Fig 2

Fig. 3 Noncontrast CT Pelvis: A CT-guided biopsy of the perirectal mass was performed in 2022, describing the mass as heterogeneously hypodense with areas of low density and calcification. Four core biopsy specimens were obtained.

Fig 3

Fig. 4 (A) Noncontrast T1 MRI Pelvis: Follow-up MRI in 2023 confirmed the stability of the right perirectal nodule with no new or enlarging pelvic mass or lymphadenopathy (white arrow). The MRI confirmed the absence of a perianal fistula or abscess, and no significant changes were noted compared to the prior MRI from 2022. (B) T2 MRI Pelvis: Follow-up MRI in 2023 confirmed the stability of the right perirectal nodule with no new or enlarging pelvic mass or lymphadenopathy (white arrow). The MRI confirmed the absence of a perianal fistula or abscess, and no significant changes were noted compared to the prior MRI from 2022.

Fig 4

Histopathological and immunohistochemical analysis showed normal CEA levels, suggesting no relation to colon cancer recurrence.

Following the mass's surgical removal, the patient's symptoms significantly improved. The heterogeneity of the hypodense perirectal mass had significantly decreased, according to a comparison between the patient's preoperative scan and the clinical imaging. Any lingering symptoms, such as fever, sweating, and joint discomfort were not noted in the patient. Significant symptom improvement and the absence of recurrence over a 2-year period was observed during the postsurgical follow-up, underscoring the need of thorough imaging and clinical correlation in the diagnosis and treatment of RDD.

Discussion

RDD is a rare, benign histiocytic disease that mostly affects lymph nodes but can also affect the skin, soft tissues, respiratory tract, and central nervous system. The illness is defined by an excess of histiocytes, a type of white blood cell that can accumulate in many body tissues. There are very few cases of RDD involving the abdomen and pelvis that have been documented in the literature [6]. Since abdominal RDD imaging signals are vague and can closely resemble other illnesses like lymphoma or metastatic cancer, this rarity presents a diagnostic problem. Mass lesions involving both soft tissue and skeletal structures that exhibit varying enhancement patterns on contrast studies are common imaging characteristics. Additional diagnostic testing and a high index of suspicion are required considering these nonspecific findings.

RDD is an uncommon form of histiocytic illness that is characterized by extranodal involvement, particularly the pelvis, and painless lymphadenopathy. The differential diagnosis for RDD should include lymphoma, metastatic carcinoma, and other histiocytic illnesses such LCH and ECD based on the imaging results [5]. On imaging, swollen lymph nodes and tumors associated with lymphoma may be difficult to differentiate from other disorders. In imaging, metastatic cancer can mimic other disease processes by presenting as lytic or sclerotic lesions. A rare condition called Langerhans cell hyperproliferation (LCH) can cause lesions in the skin, bones, and other organs. It may include the pelvis and manifest as lytic bone lesions [3]. Another uncommon histiocytic condition, ECD usually affects the long bones but can also affect the pelvic. It can appear as sclerosis in imaging and is characterized by xanthogranulomatous infiltration of tissues.

To distinguish RDD from other histiocytic illnesses and cancers, a biopsy and immunohistochemistry staining are necessary. This method directs the best possible patient care and guarantees an accurate diagnosis. Large histiocytes with copious amounts of pale cytoplasm that show emperipolesis—the engulfment of lymphocytes or other cells—are the defining histological characteristic of RDD (Fig. 5). By using immunohistochemistry, these histiocytes can be distinguished from other histiocytic illnesses such Langerhans cell histiocytosis (LCH) and Erdheim-Chester disease (ECD) by being positive for S-100 protein and CD68 and negative for CD1a [4]. Since the treatment plan varies according to the degree and breadth of the condition, an accurate diagnosis of RDD is essential. RDD patients typically get conservative care that emphasizes close observation and monitoring, especially if they are asymptomatic or have a mild form of the condition [6]. Many times, the illness will not need drastic treatment and will progress in a benign manner.Fig. 5 High magnification histopathological image demonstrating emperipolesis, where lymphocytes are engulfed within histiocytes.

Fig 5

More aggressive treatment might be required, though, if RDD is symptomatic, progressing, or producing a great deal of morbidity. Because of its anti-inflammatory properties, corticosteroids are frequently regarded as the first line of treatment. They can lessen the size of lesions and ease symptoms, but because they may have negative side effects, long-term usage of them needs to be carefully monitored. Patients with RDD may benefit from a multidisciplinary approach comprising radiologists, pathologists, oncologists, and surgeons to customize the management plan to their individual needs in addition to pharmaceutical treatments. Surgical surgery may be considered in certain cases, such as this one, where patients do not respond appropriately to corticosteroids or have severe adverse effects [7]. Surgical surgery is often saved for situations in which RDD seriously impairs function or involves vital structures, such as airway blockage or compressive sensations in the spinal cord.

Imaging investigations and routine follow-up are crucial for tracking the course of the disease and how well it responds to therapy. RDD patients are treated individually based on their clinical presentation, the severity of their disease, and how well they respond to first medicines. Histopathological examinations that provide an early and accurate diagnosis aid in prognostication and improve patient outcomes in addition to guiding suitable treatment [8].

In conclusion, RDD ought to be considered when making a differential diagnosis for pelvic and retroperitoneal masses, especially in cases where the masses show atypically. The gold standard for a conclusive diagnosis is still an immunohistochemical stain and biopsy, and the course of treatment should be customized based on the clinical presentation and severity of each patient's disease. In addition to helping to differentiate RDD from other cancers, an early and precise diagnosis using histopathological and immunohistochemical investigation also guarantees that patients receive focused and appropriate treatment, thereby enhancing their overall prognosis and quality of life. For patients with RDD to have the best possible outcomes, comprehensive management and ongoing monitoring are crucial.

Patient consent

I have obtained written informed consent for publication of this article from the patient.

Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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References

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