Granulomatous Skin Diseases in a Tertiary Care Portuguese Hospital: A 10-Year Retrospective Study

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.

Clinicopathologic Features of Tissue Granulomas in Transplant Recipients: A Single Center Study in a Nontuberculosis Endemic Region

CONTEXT.—

There is a paucity of literature about tissue granulomas in transplant patients.

OBJECTIVE.—

To characterize the clinicopathologic features of granulomas in this population and develop a clinically judicious approach to their evaluation.

DESIGN.—

We performed chart reviews of solid organ and allogeneic hematopoietic stem cell transplant recipients at Yale New Haven Hospital to identify patients with granulomas on biopsy obtained pathologic specimens. Pretransplant and posttransplant specimens were included. Data points included demographics, clinical presentation, epidemiologic risk factors, biopsy indication, location and timing, immunosuppression, histopathology, microbiology, and associated clinical diagnosis. Granuloma-related readmissions and mortality were recorded at 1, 3, and 12 months.

RESULTS.—

Biopsy proven granulomas were identified in 56 of 2139 (2.6%) patients. Of 56, 16 (29%) were infectious. Common infectious etiologies were bartonellosis (n = 3) and cytomegalovirus hepatitis (n = 3). Tuberculosis was not identified. Clinical symptoms prompted tissue biopsy in 27 of 56 (48.2%) cases while biopsies were obtained for evaluation of incidental findings or routine disease surveillance in 29 of 56 (51.8%). Presence of symptoms was significantly associated with infectious etiologies; 11 of 27 (40.7%) symptomatic patients compared with 5 of 29 (17.2%) asymptomatic patients had infectious causes. One death from granulomatous cryptogenic organizing pneumonia occurred. In pretransplant asymptomatic patients, no episodes of symptomatic disease occurred posttransplantation.

CONCLUSIONS.—

Granulomas were uncommon in a large transplant population; most were noninfectious but presence of symptoms was associated with infectious etiologies. Granulomas discovered pretransplant without clear infectious etiology likely do not require prolonged surveillance after transplantation. Symptomatology and epidemiologic risks factors should guide extent of microbiologic evaluation.

Histopathologic features of noninfectious granulomatous disorders involving the skin

Granulomatous dermatoses may represent primary skin inflammation or can serve as the harbinger of a multitude of underlying systemic disorders or drug reactions. Taken together with clinical findings, the microscopic features from skin biopsy can allow recognition of various patterns and facilitate a precise diagnosis. Accurate classification of entities in this category of inflammatory dermatoses may prompt clinicians to investigate for underlying systemic problems, thereby allowing the pathologist to add considerable value in the care of affected patients. This review article categorizes clinical and microscopic features of common and uncommon causes of noninfectious dermal and subcutaneous granulomatous inflammation.