Yun JH, Lee JY Kim MK, et al: Clinical and pathological features of generalized granuloma annulare with their correlation: a retrospective multicenter study in Korea.
Cohen PR: Granuloma annulare associated with malignancy.
Shimizu S, Yasui C, Tsuchiya K: Atypical generalized granuloma annulare associated with two visceral cancers.
Histologic analysis demonstrated a palisading, necrobiotic granulomatous dermatitis with increased interstitial mucin (highlighted by colloidal iron stain shown in inset) consistent with granuloma annulare (Figure 3).
Histologic analysis demonstrated an interstitial, folliculocentric, and perineurovascular lymphohistiocytic infiltrate (Figure 4) with increased dermal mucin deposition confirmed by colloidal iron staining, consistent with interstitial or incomplete" granuloma annulare.
The histologic differential diagnosis of postherpetic granuloma annulare includes idiopathic granuloma annulare; sarcoidosis; foreign-body-type giant cell reactions, such as to silica, zirconium, beryllium, and tattoo pigments (most commonly to red); metastatic Crohn disease; and infections such as tuberculoid leprosy and tuberculosis.
To estimate the prevalence of dyslipidemia in granuloma annulare patients, the investigators reviewed the medical records of 140 adult patients with idiopathic granuloma annulare and 420 controls matched for age, gender, race, type 2 diabetes, hypertension, and hypothyroidism, according to data presented in a poster at the meeting.
For associations between disease characteristics and comorbidities, the granuloma annulare patients were divided into subgroups based on disease extent (localized, disseminated, generalized), morphology (annular, nonannular), and histopathology (interstitial, palisaded, mixed, deep).
Clinical correlation is important in the diagnosis of granuloma annulare because many entities can mimic the disorder both clinically and histologically (Table 3).
In general, granuloma annulare is considered a self-limiting disease, with lesions expected to resolve within 2 years for >50% of patients (1-3).
Ulcerating ES lesions have raised margins and are nonhealing, clinically resembling granuloma annulare.
Epithelioid sarcoma has many histopathologic mimics, including benign and malignant conditions, such as granuloma annulare, necrobiosis lipoidica, chronic granulomatous inflammation (especially rheumatoid nodules), fibrous histocytoma, nodular fasciitis, fibromatosis, giant cell tumor of tendon sheath, melanoma, clear-cell sarcoma of the tendon and aponeurosis (amelanotic melanoma of soft part), schwannoma, metastatic squamous cell carcinoma, metastatic adenocarcinoma (especially renal cell carcinoma), synovial sarcoma, epithelioid hemangioendothelioma, epithelioid leiomyosarcoma, and malignant extrarenal rhabdoid tumors of the soft tissue.
In some examples, the clinical appearance suggests a diagnosis of granuloma annulare.
The overall architecture and bland appearance of the neoplastic cells may lead to misdiagnosis of ES as granuloma annulare or rheumatoid nodule.
Detection of mummified remnants of individual necrotic epithelioid cells in the centers of the tumor nodules, as opposed to the suppurative, fibrinoid, or caseous necrosis of necrotizing granulomata, or the accumulated stromal mucin of granuloma annulare
should also alert one to the possibility of epithelioid sarcoma.