BALTIMORE — Marked papillary edema may be present in patients with systemic lupus erythematosus. The finding is an accepted feature of polymorphous light eruption, but is not recognized in lupus.
After finding marked papillary dermal edema in the histopathologic specimens of four patients with systemic lupus erythematosus (SLE), a group of investigators assessed the frequency of papillary dermal edema as a histologic feature of SLE in biopsies read at University of California, San Francisco from 2000 to 2003.
The investigators—Dr. Laura B. Pincus, Dr. Timothy H. McCalmont, and Dr. Philip E. Le Boit, all of UCSF—conducted a computerized search of the UCSF dermatopathology database for cases coded as SLE, identifing 502 cases. The researchers excluded cases if the microscopic findings were suspicious for but not diagnostic of SLE or if the term “lupus” was not included in the final diagnosis. A total of 131 specimens qualified for review.
The findings were presented in a poster at the annual meeting of the American Society of Dermatopathology.
The degree of papillary edema was markedly similar to that which can be observed in sections from patients with polymorphous light eruption (PMLE).
Two physicians reviewed the 131 specimens that qualified for inclusion for the presence of papillary dermal edema. In addition, the following other well-established features of SLE were scored, including:
▸ The presence or absence of mucin, epidermal atrophy, acanthosis, hyperkeratosis, and follicular plugging;
▸ Perijunctional and perifollicular alteration—rated as vacuolar alteration only, vacuolar change with necrotic keratinocytes, or vacuolar change with necrotic keratinocytes and confluent necrosis;
▸ Basement membrane thickening evident with routine hematoxylin-eosin staining alone or with periodic acid-Schiff, diastase-resistant staining (presence/absence);
▸ The density of perivascular and periadnexal infiltrate and the percentage of inflammatory cell types present.
Marked papillary dermal edema was present in 8% of cases. Reticular dermal mucin deposition was evident in 35% of cases and usually could be appreciated in conventional (hematoxylin-eosin) sections.
In terms of perijunctional manifestations, the majority of cases showed necrotic keratinocytes both at the epidermal-dermal junction as well as around the folliculosebaceous units. Confluent necrosis was rare. Basement membrane thickening was present in 12% of cases. Roughly half of the cases showed a modest dermal infiltrate, while half showed a relatively dense superficial and deep infiltrate. In virtually all cases, the dermal infiltrate was composed primarily of lymphocytes, with few granulocytes present.
Marked papillary dermal edema is a well-established microscopic feature of PLME. The clinical differential diagnosis of sun-induced facial plaques often includes both SLE and PMLE. “The presence of papillary dermal edema in histopathologic sections should not preclude a diagnosis of SLE,” the authors concluded. In addition, “papillary dermal edema (alone) is not a reliable microscopic feature to distinguish SLE from PMLE.”
Since the histopathologic sections from this patient showed papillary dermal edema, some might be tempted to render a diagnosis of polymorphous light eruption. However, the findings of this study show that papillary dermal edema can be seen in SLE as well. Vacuolar alteration also pointed to a diagnosis of SLE rather than PMLE.
Dr. Pincus is a dermatology resident; Dr. LeBoit and Dr. McCalmont are professors of pathology and dermatology.
Histology showed papillary edema in a 53-year-old woman who presented with erythematous plaques. Courtesy Dr. Timothy H. McCalmont