Metastatic Crohn’s disease: a histopathologic study of 12 cases

A Review of Cutaneous Extraintestinal Manifestations of Inflammatory Bowel Disease in Skin of Color

The incidence of inflammatory bowel disease (IBD) is increasing in racial and ethnic minority groups. Cutaneous extraintestinal manifestations (EIMs) of IBD are well-known comorbid conditions that can occur in both active and quiescent IBD. Historically, cutaneous EIMs of IBD are described in White skin with a lack of literature describing these conditions in darker skin tones. This potentially creates a knowledge gap and awareness among providers in recognizing these conditions and offering therapy in a timely manner to non-White patients. This review aims to describe the cutaneous manifestations of IBD in a wide range of skin tones with several examples to improve awareness. With further awareness, this review will enable to provide equitable care to IBD patients with cutaneous EIMs.

A Challenging Case of Metastatic Crohn's Disease Without Gastrointestinal Manifestations

Metastatic Crohn's disease (MCD) is a rare cutaneous manifestation of Crohn's Disease (CD), defined as non-caseating, granulomatous skin lesions non-contiguous with the gastrointestinal (GI) tract. Most patients with MCD either have concomitant classic manifestations of CD or develop them within a few months to years. We report a case of MCD without known involvement of the GI tract, after more than three years from diagnosis. After failure or intolerance to several conventional treatments, including oral corticosteroids and azathioprine, adalimumab was initiated with a good response.  Diagnosis of cutaneous CD is made by a combination of clinical and histopathological findings. Therapeutic options include topical, intralesional, and systemic corticosteroids as well as topical and systemic immunosuppressants and immunomodulators. Surgical excision may be considered for refractory cases.

Managing metastatic Crohn's disease: a single center experience, review of the current evidence, and treatment algorithm

BACKGROUND

Crohn's disease (CD) is an inflammatory bowel disease (IBD) that, besides gastrointestinal symptoms, may encompass extra-intestinal symptoms, such as dermatological manifestations. Of those, metastatic CD (MCD) is a rare extra-intestinal manifestation for which the management is uncertain.

METHODS

We conducted a retrospective case series of patients with MCD seen at the University hospital Leuven, Belgium, combined with an overview of the recent literature. Electronic medical records were searched from January 2003 till April 2022. For the literature search, Medline, Embase, Trip Database, and The Cochrane Library were searched from inception to April 1, 2022.

RESULTS

A total of 11 patients with MCD were retrieved. In all cases noncaseating granulomatous inflammation was found on skin biopsies. Two adults and one child were diagnosed with MCD prior to their diagnosis of CD. Seven patients were treated with steroids (intralesional, topical or systemic). Six patients needed a biological therapy to treat MCD. Surgical excision was performed in three patients. All patients reported a successful outcome and most cases achieved remission. The literature search yielded 53 articles, including three reviews, three systematic reviews, 30 case reports and six case series. A treatment algorithm was generated based on literature and multidisciplinary discussion.

CONCLUSION

MCD remains a rare entity and diagnosis is often difficult. A multidisciplinary approach including skin biopsy is necessary to diagnose and treat MCD efficiently. Outcome is generally favorable, and lesions respond well to steroids and biologicals. We propose a treatment algorithm based on the available evidence and multidisciplinary discussion.

Anogenital Crohn's Disease and Granulomatosis: A Systematic Review of Epidemiology, Clinical Manifestations, and Treatment

BACKGROUND AND AIMS

Metastatic Crohn's disease is an extraintestinal cutaneous manifestation characterised by non-specific inflammatory lesions anatomically separate from the gut; genital involvement is rare. We conducted a systematic review of anogenital Crohn's disease and granulomatosis, to provide a synthesis of epidemiology, clinical features, and treatment outcomes.

METHODS

A systematic search of the literature was conducted via MEDLINE, EMBASE, and the Cochrane database from inception to December 1, 2020. Two investigators extracted and analysed study data. Response and remission were defined as partial improvement or complete resolution of symptoms and examination findings, respectively.

RESULTS

Of 9381 screened studies, 185 articles, [410 cases: 273 female, 137 male] were included. The predominant clinical features were oedema, ulcers, fissures, and hypertrophic lesions. Adults and children present similarly. Luminal Crohn's disease was diagnosed in nearly 80% of cases including 45-80% patients without gastrointestinal symptoms (time to inflammatory bowel disease [IBD] from anogenital Crohn's disease diagnosis [range] -43 to 11 years). Antibiotics, corticosteroids, thiopurines, and anti-tumour necrosis factor [TNF] therapy were the most frequently prescribed agents. At final follow-up, non-response, response, and remission rates were 37/304 [12%], 267/304 [88%], and 114/304 [38%], respectively. Oedema was associated with a poor response to topical therapy. Greater response rates to anti-TNF therapy were seen in patients prescribed concomitant immunomodulation [24/25, 96% vs 67/90, 74%, p = 0.02].

CONCLUSIONS

We provide an illustrative summary of the clinical presentation and treatment effectiveness of this rare, under-recognised condition, and a proposed algorithm for approach and management. Prospective studies with longer follow-up are required to define optimal treatment strategies.

Non-Infectious Granulomatous Dermatoses: A Pathologist's Perspective

Granulomatous dermatitis (GD) is one of the commonest tissue reaction patterns encountered in dermatopathology practice. Granulomatous inflammation in the skin can be seen in a wide range of conditions, thus, granulomatous dermatitis always poses significant challenge even to the astute dermatologists and dermatopathologists. Broadly, granulomatous dermatitis is divided into two groups-infectious and non-infectious, the prevalence of both highly variable and show overlapping pathology. However, there are subtle histological clues, which when combined with clinical features, help to narrow down the differential diagnosis. Thus, a good Clinicopathological correlation (CPC) along with histochemical stains, culture and ancillary techniques including molecular studies are required for arriving at a definite diagnosis. In this review, we shall discuss the histological clues to diagnose non-infectious granulomatous dermatitis (NIGD) and their differential diagnoses.

Metastatic Crohn's disease: an underestimated entity

Cutaneous metastatic Crohn's disease (MCD) is a rare but challenging dermatologic manifestation of Crohn's disease. It is histologically defined as the presence of non-caseating granulomas at skin sites separated from and non-contiguous to the gastrointestinal tract. Cutaneous metastatic Crohn's disease should be distinguished from the much more frequent contiguous cutaneous manifestations of Crohn's disease that present at perianal or, less common, peristomal sites with direct extension from the intestine to the adjacent skin. Versatile clinical presentation and the fact that occurrence can predate the initial diagnosis of Crohn's disease may lead to misdiagnosis, delayed treatment and underreporting. As case numbers are small and randomized controlled studies on management are lacking, the therapeutic approach remains challenging and is often unsatisfactory. We here performed a systematic literature search identifying 264 published pediatric and adult cases of MCD and additionally report three of our own cases. Our review summarizes clinical characteristics, putative etiopathology, histologic findings, differential diagnoses and treatment options for MCD.

Metastatic Crohn Disease: A Clinicohistological Appraisal From a Tertiary Care Center in India

BACKGROUND

Granulomatous dermatitis due to noncontiguous involvement of Crohn disease (CD) of the gut has been described as metastatic CD (MCD). MCD is the rarest form of cutaneous manifestations of CD. This study aims to analyze the clinicohistological features of MCD in a tertiary care center of India.

MATERIALS AND METHODS

A retrospective review of patients diagnosed clinically and histologically with MCD over past 5 years was performed. Data on cutaneous features, histological findings, and response to treatment were collected.

RESULTS

Twelve patients (3 men and 9 women) with a mean age of 29 years were identified. All women had vulval involvement in the form of edema (80%), ulceration (60%), and fistula (20%). Among the 3 men, 2 had perineal and scrotal swelling and ulcer, whereas the third patient presented with leg ulcer. Intestinal CD was already diagnosed in 50% patients (5/10) at cutaneous presentation, whereas it was diagnosed subsequently in 30% (3/10) cases. Histological examination revealed nonnecrotizing granulomatous inflammation in the dermis in 11 patients (92%). Additional histological features included eosinophilic infiltrate (58%), panniculitis (33%), and vasculitis (33%). The patients were treated with various combinations of oral prednisolone, metronidazole, minocycline, azathioprine, and subcutaneous adalimumab with partial relief.

CONCLUSION

MCD shows a wide spectrum of clinical presentation, with anogenital involvement being the most common. Histology reveals nonnecrotizing granulomas in the dermis in majority of the cases. The diagnosis is extremely challenging in patients without gastrointestinal involvement at presentation, and thus, a high index of suspicion is imperative.

Cutaneous manifestations of metastatic Crohn's disease

Metastatic Crohn's disease is a rare cutaneous complication of primary Crohn's disease. It is a granulomatous inflammatory process, similar to the pathogenic mechanism of Crohn's disease, that occurs in sites discontiguous from the gastrointestinal tract. Metastatic Crohn's disease can precede the development of Crohn's disease by months to years, and children are more likely to present with metastatic Crohn's disease in the absence of gastrointestinal symptoms. Given that approximately 30% of individuals with Crohn's disease present in childhood, early recognition of extraintestinal manifestations of Crohn's disease such as metastatic Crohn's disease can aid in timely diagnosis and management of bowel disease. We present data from two pediatric cases of metastatic Crohn's disease recently seen at our institution in addition to the 61 reported cases of pediatric metastatic Crohn's disease in the literature. This review article will focus on the epidemiology, pathogenesis, clinical features, and histology of and treatment options for pediatric metastatic Crohn's disease.

Metastatic Crohn's disease despite infliximab therapy

Metastatic Crohn’s disease is a rare extraintestinal manifestation of Crohn’s disease. It is characterized by polymorphic skin lesions formed by non-caseating granulomas located on anatomical sites distant from the gastrointestinal tract. We report a rare case of metastatic Crohn’s disease, simultaneously displaying multiple clinically heterogeneous cutaneous lesions, in a patient with previously diagnosed Crohn’s disease in remission due to anti-TNF-α use. This case highlights the need for high clinical suspicion and early biopsy in the setting of a patient with Crohn’s disease and persistent skin lesions, even under biologic therapy. Furthermore, it reinforces the need of monitoring of the serum level of infliximab, increasing the dose in case it is low or undetectable.

Inflammatory Dermatopathology for General Surgical Pathologists

Owing to the wide variety and complexity of inflammatory skin diseases, inflammatory dermatopathology can be a challenging topic for dermatopathologists and general surgical pathologists alike. Following a basic tissue reaction pattern approach, this article reviews the most common and important entities of each pattern, with emphasis on differential diagnosis, diagnostic pitfalls, and appropriate workup when indicated. A few dermatologic emergencies are also discussed.

Clinical experience and diagnostic algorithm of vulval Crohn's disease

BACKGROUND AND AIM

Vulval Crohn's disease (VCD) is a rare extraintestinal cutaneous manifestation of Crohn's disease. No consensus on the diagnostic workup and therapeutic management of this condition has been provided in the current literature.

PATIENTS AND METHODS

Retrospective, multicentre descriptive case series of female patients diagnosed and treated with VCD. By chart review, data on initial symptoms, clinical courses, histologic findings and therapeutic management were collected.

RESULTS

Fifteen female patients with a median age of 28 years (interquartile range: 28-44 years) suffering from Crohn's disease of the ileum (27%), colon (33%) and ileocolon (40%) were included. VCD manifested most frequently with vulval swelling (93%), pain (80%) and erythema (73%). Histologic analysis demonstrated granulomatous inflammation in 78% and a mixed inflammatory cell infiltrate in 67% of cases. In eight (53%) cases, topical therapy resulted in temporary reduction of vulval symptoms. Combotreatment with immunosuppressive agents and tumour necrosis factor α inhibitors was the most effective second-line therapy: five (33%) patients achieved sustained clinical remission with this therapeutic strategy.

CONCLUSION

The diagnostic workup of VCD is challenging and should be approached in a multidisciplinary manner. Histopathologic analysis of the vulva supports the diagnosis. Topical therapy and systemic treatment with immunosuppressive agents and tumour necrosis factor α inhibitors are advised to treat this condition.

Cutaneous Crohn's disease with superimposed psoriasis: A unique case with overlapping histology

Crohn's disease (CD) is an idiopathic, chronic inflammatory disorder of the gastrointestinal tract. We recently encountered a unique case in which a patient with longstanding CD presented with skin lesions with histopathologic features of both psoriasis and granulomatous inflammation suggestive of cutaneous CD. To our knowledge, this has not been described concomitantly in the same patient, in the same lesions. Review of the literature suggests that the intersection of these 2 histopathological reaction patterns may not be pure coincidence. Clinical-pathologic correlation of this case will be discussed, along with a review of the potential mechanisms of this unique disease presentation.

Metastatic Crohn's Disease: An Approach to an Uncommon but Important Cutaneous Disorder

Objective. To provide physicians with a clinical approach to metastatic Crohn's disease (MCD). Main Message. Metastatic Crohn's disease, defined as skin lesions present in areas noncontiguous with the gastrointestinal tract, is the rarest cutaneous manifestation of Crohn's disease. MCD lesions vary in morphology and can arise anywhere on the skin. MCD presents equally in both sexes and across age groups. Cutaneous findings may precede, develop concurrently with, or follow gastrointestinal involvement. A detailed history and thorough physical examination including a full-skin exam may help to exclude other dermatoses, as MCD can mimic other common disorders. A biopsy is required for a definitive diagnosis. Treatment options for MCD remain underwhelming due to the lack of randomized control studies and varying responses of reported therapeutic methods. Topical, intralesional, and systemic corticosteroids, antibiotics, traditional immunosuppressants, and surgery have shown mixed results. Recently, biologics have shown promise, even with refractory cases of MCD. Conclusion. MCD is an important cutaneous manifestation of this inflammatory disorder. Although a rare entity, early recognition can provide opportunity for successful therapeutic intervention.

Case for diagnosis. Metastatic Crohn's disease

Metastatic Crohn's disease is a rare skin manifestation, defined by granulomatous skin lesions that are discontinuous to the affected gastrointestinal tract and histopathologically resembling inflammatory bowel lesions. Up to 44% of patients with Crohn's disease have cutaneous manifestations, of which metastatic lesions are the least common. We present a case of an adolescent with refractory Crohn's disease and persistent papules and plaques on the skin.

Assessment of histologic disease activity in Crohn's disease: a systematic review

BACKGROUND

Crohn's disease (CD) is an idiopathic, chronic, transmural inflammatory disorder of the gastrointestinal tract. Because mucosal involvement is near-universal, endoscopic healing has emerged as an important aspect in improving outcome. However, resolution of histologic disease activity has potential to convey additional benefit beyond that attained with endoscopic healing alone. Validated scoring systems of histologic disease activity are required to further assess this possibility. The aim of this study was to systematically review the existing histologic disease activity indices (HDAI) for CD and to assess their operating properties and potential use as outcome measures in clinical trials.

METHODS

MEDLINE (Ovid), EMBASE (Ovid), PubMed, the Cochrane Library (CENTRAL), and Digestive Disease Week (DDW) abstracts were searched from 1981 to April 2013 for applicable studies to identify relevant studies for review and analysis.

RESULTS

In total, 3732 citations were screened to obtain 89 articles for inclusion. Sixty-six HDAIs were characterized as either stepwise or numerical instruments. These HDAIs were used for either assessment of response to medical therapy or for comparison with biomarkers or imaging tests. None of the HDAIs identified was developed according to currently accepted methods for developing evaluative instruments, and none have been formally validated.

CONCLUSIONS

Measurement of histologic disease activity has potential value in CD; however, no validated measures are available. Additional research is needed to develop a methodologically rigorous instrument for use in clinical investigation and potentially for clinical practice.

Cutaneous sarcoidosis: clinicopathologic study of 76 patients from Lebanon

BACKGROUND

Sarcoidosis is a multi-system granulomatous disease of unknown etiology. The skin is involved in 25% of cases. Studies on cutaneous sarcoidosis from our region are lacking.

OBJECTIVES

This study was conducted to describe clinical and histopathologic findings in all patients diagnosed with cutaneous sarcoidosis at the American University of Beirut Medical Center between 1992 and 2010 and to compare findings with those published in the literature.

METHODS

Clinical charts of patients with cutaneous sarcoidosis were retrospectively reviewed. Extracutaneous lesions were classified by organ involvement. Treatment was documented. Pathology specimens were reviewed.

RESULTS

Cutaneous sarcoidosis was diagnosed in 76 Lebanese patients, 79% of whom were women. Mean age at diagnosis was 48 years. A total of 29% of patients had systemic disease that was commonly associated with lupus pernio lesions and subcutaneous sarcoidosis. The most common cutaneous lesions were sarcoidal plaques. The histopathologic features in our series did not differ from those described in the literature, except for the documented presence of a grenz zone. Interestingly, 23% of biopsy specimens contained perineural granulomas, raising the possibility of tuberculoid or borderline tuberculoid leprosy. Foreign bodies were detected in 10% of cases (all had systemic involvement), supporting the opinion that sarcoidosis and granulomatous foreign body reaction are not mutually exclusive.

CONCLUSIONS

The clinical and histopathologic features of cutaneous sarcoidosis patients in the present series are generally comparable with those published in the literature, with minor differences. Clinically, the most commonly seen lesion was plaque. Microscopically, cutaneous sarcoidosis may exhibit a grenz zone and may show perineural inflammation and foreign bodies.

Treatment of a Crohn's disease-related cutaneous facial lesion with topical tacrolimus

We report a case of an orofacial lesion in Crohn's disease successfully treated with tacrolimus ointment. A 22-year-old woman with Crohn's disease presented with a discharging lesion on the right side of her face. Intraorally, there was a resultant loss of the sulcal depth. She reported a 1-year history of variable right-sided facial swelling for which she had undergone extraoral incision and drainage, resulting in localized paresthesia and nonhealing of the incision site. Following exclusion tests, a treatment of twice-daily extraoral application of tacrolimus 0.1% ointment was commenced. Upon review, the lesion had reduced in size, with minimal discharge. Further improvement over 12 months of tacrolimus use resulted in a satisfactory cosmetic result as well as resolution of the intraoral features and reestablishment of the full sulcal depth. This case illustrates the successful use of topical tacrolimus to treat a cutaneous manifestation of Crohn's disease.

Metastatic Crohn's disease: a review and approach to therapy

Metastatic Crohn's disease (CD) is a rare cutaneous manifestation of CD that was first described nearly 50 years ago. Many subsequent reports have defined its most common clinical and histopathologic features. The pathogenesis underlying metastatic CD is unknown but various hypotheses exist. An established standard therapy is lacking. Owing to its rarity and nonspecific clinical presentation along with the diversity of inflammatory skin disorders that often complicate CD, the diagnosis of metastatic CD may be overlooked. This report highlights the salient features of this disorder to facilitate recognition and management of this rare dermatosis.

Wolf Isotopic Response Manifesting as Postherpetic Granuloma Annulare: A Case Series

Context.— Wolf isotopic response has infrequently been reported in the literature, mainly as isolated case reports.

Objective.— To aid in recognition of the occurrence of postherpetic granuloma annulare for accurate histologic interpretation of granulomatous dermatitides.

Design.— We report 5 cases of patients with Wolf isotopic response manifesting as granuloma annulare, developing in a site of previous herpes zoster, and discuss the clinicopathologic findings.

Results.— Previous infection with herpes zoster or herpes simplex virus was found in 5 of 5 cases reported. The differential diagnosis of a dermal lymphohistiocytic infiltrate with multinucleated giant cells includes postherpetic granuloma annulare.

Conclusions.— All cases of postherpetic Wolf isotopic response reported in this series revealed granuloma annulare, with a perineurovascular or perifollicular pattern of lymphohistiocytic infiltration including multinucleated giant cells, and occurred following herpes zoster or herpes simplex infection, although herpes viral infection was not always associated with a subsequent isotopic eruption. Awareness of this entity can aid in the clinicopathologic diagnosis of granuloma annulare occurring at the site of prior herpes viral infection.

Current knowledge in inflammatory dermatopathology

The complex and fascinating spectrum of inflammatory skin disease, and the comprehension of it, is ever expanding and evolving. During the first decade of the 21st century, numerous advances in the understanding of inflammatory disease mechanisms have occurred, particularly in psoriasis and atopic dermatitis. Continuation of this trend will assure a future in which molecular tests for biomarkers of immediate clinical relevance are used in routine patient care, not only for diagnosis but also for prognosis and management. This article focuses on selected recent or noteworthy developments that are clinically relevant for the histologic diagnosis of inflammatory skin diseases.

Surgical management of gluteal metastatic cutaneous Crohn's disease

Metastatic cutaneous Crohn's disease is a rare entity first described by McCallum et al. in 1976. It is diagnosed when histologically characteristic granulomata are seen at a site not contiguous with inflammatory disease in the gastrointestinal tract. We herein report presentation, diagnosis and management of a 28 year old lady with disabling, symptomatic cutaneous Crohn's of the buttocks and natal cleft refractory to Infliximab therapy. To the best of our knowledge only four other adult cases have been reported in the literature of metastatic cutaneous Crohn's disease of the buttock area distant from a flexure or area of skin apposition. The differential diagnosis in this case was Hidradenitis Suppurativa. A good cosmetic result and excellent symptom control were achieved with extensive debridement, wide local excision, vacuum assisted closure and delayed skin grafting.

Metastatic Crohn disease: a rare cutaneous entity

Metastatic Crohn disease is a rare cutaneous disorder characterized by noncaseating, granulomatous skin lesions present at sites anatomically separate from the gastrointestinal tract. It is the least common dermatologic manifestation of Crohn disease, and the differential diagnosis includes numerous similarly appearing, granulomatous skin entities. Males and females appear to be equally affected, and children tend to present with clinical lesions different from those of adults. An integration of clinical information, microscopic findings, and ancillary studies is necessary to accurately diagnose this rare cutaneous disease. Our objective is to review the clinical features, histopathologic characteristics, suggested pathogenesis, differential diagnosis, and current therapeutic options of metastatic Crohn disease.

The pan-B cell marker CD22 is expressed on gastrointestinal eosinophils and negatively regulates tissue eosinophilia

CD22 is currently recognized as a B cell-specific Siglec and has been exploited therapeutically with humanized anti-CD22 mAb having been used against B cell leukemia. In this study, tissue-specific eosinophil mRNA microarray analysis identified that CD22 transcript levels of murine gastrointestinal (GI) eosinophils are 10-fold higher than those of lung eosinophils. To confirm the mRNA data at the protein level, we developed a FACS-based protocol designed to phenotype live GI eosinophils isolated from the murine lamina propria. Indeed, we found that jejunum eosinophils expressed remarkably high levels of surface CD22, similar to levels found in B cells across multiple mouse strains. In contrast, CD22 was undetectable on eosinophils from the colon, blood, thymus, spleen, uterus, peritoneal cavity, and allergen-challenged lung. Eosinophils isolated from newborn mice did not express CD22 but subsequently upregulated CD22 expression to adult levels within the first 10 d after birth. The GI lamina propria from CD22 gene-targeted mice harbored more eosinophils than wild type control mice, whereas the GI eosinophil turnover rate was unaltered in the absence of CD22. Our findings identify a novel expression pattern and tissue eosinophilia-regulating function for the "B cell-specific" inhibitory molecule CD22 on GI eosinophils.

Comorbidities of hidradenitis suppurativa (acne inversa)

Comorbidities of hidradenitis suppurativa (acne inversa) were reviewed by extracting original and review publications included in MEDLINE, EMBASE and COCHRANE libraries using the terms "hidradenitis," "Verneuil" and "acne inversa." Follicular occlusion disorders, inflammatory bowel diseases, especially Crohn disease, spondylarthropathy, other hyperergic diseases, genetic keratin disorders associated with follicular occlusion and squamous cell carcinoma were the most common hidradenitis suppurativa comorbid diseases. A first classification of these major comorbidities and their possible genetic background reveals a list of chromosome loci and genes, which could be hidradenitis suppurativa candidates. Most of these diseases belong to the group of autoinflammatory disorders, where th17 cell cytokines seem to play a central role.

Granulomatous vasculitis in Crohn's disease: a clinicopathologic correlate of two unusual cases

Cutaneous complications occur not uncommonly in patients with Crohn's disease (CD). Gastrointestinal CD often shows non-caseating granulomas and a rare cutaneous finding in CD is a sterile granulomatous infiltrate not contiguous with the GI tract, termed extraintestinal CD (ECD). The clinical presentation of ECD is diverse. The most common histopathological presentation is a superficial and deep granulomatous infiltrate that often accompanies a mixed perivascular infiltrate. Here we report two patients with CD and skin lesions characterized on microscopy by granulomatous vasculitis. A 29-year-old female presented with papules and ulcerated nodules above the ankle. The biopsy showed dermal and superficial subcutaneous involvement by a vasocentric infiltrate of mononuclear and multinucleated histiocytes as well as mural fibrin deposition. A 35-year-old male presented with two tender indurated erythematous plaques with punched-out centers on the lower leg. Histopathologically, a granulomatous vasculitis of small and medium-sized vessels in the dermis and subcutis was evident. These two cases represent the rarely described phenomenon of cutaneous granulomatous vasculitis in CD. Previously reported examples of this entity are reviewed.

Dermatologic manifestations of colonic disorders

PURPOSE OF REVIEW

The skin is often a mirror for matters of internal diseases including disorders of the gastrointestinal tract. Here we enumerate many cutaneous and gastrointestinal associations and focus closely on three of the lesser known cutaneous manifestations of colonic disorders.

RECENT FINDINGS

Muir-Torre syndrome involves cutaneous sebaceous adenomas and internal malignancy; screening of cutaneous lesions for microsatellite instability, and absence of mismatch repair genes provides an opportunity for diagnosis of the syndrome. Degos' disease is a vasoocclusive disorder involving the cutaneous and gastrointestinal systems; this disease affects all ages with significant mortality, yet a benign variant only affecting the skin is described. Anecdotally reported treatments are listed. Metastatic Crohn's disease is the development of noncaseating granulomas at skin sites not contiguous with the gastrointestinal tract; cutaneous lesions may precede the onset of colonic disease or appear in the absence of active bowel disease, and extensive surgical debridement of perineal lesions is often necessary.

SUMMARY

Knowledge of these cutaneous manifestations provides an insight into the state of colonic health. These clues alert the clinician to the potential for life-threatening consequences, which leads to vigilant screening and hopefully earlier diagnosis.