Case 002: 39 Year-Old Female with Recurrent Mass in the Left Arm

Contributed by Andre Thompson, M.D., Supervised by Alan Boom, M.D.

Clinical History

39-year-old African-American female had a subcutaneous mass removed from the upper inner left arm approximately 1 year ago. The tumor itself was benign, but it was a very odd tumor. 1 month ago, the patient noted a new mass several centimeters inferior to the prior excision site. She also felt a new mass in the old incision site.

The patient underwent surgery. A lobulated mass measuring 4.0 x 3.5 x 2.5 cm was removed from the subcutaneous tissue of the left upper arm. A portion of this mass extended up to the original incision site.

Gross Findings

4.5 x 3.5 x 2.5 cm fragment of rubbery, soft tissue with attached fat. Sectioning the fragment revealed a partially encapsulated 2.5 cm nodule with a pale yellow-tan, cut surface.

Microscopic Findings

(Click a photo to view a larger image.)

Image (1) Low power: lymphatics are markedly distended by massive histocytic infiltrate. Image (2) Low power: lymphatics are markedly distended by massive histocytic infiltrate. Image (3) Low power: lymphatics are markedly distended by massive histocytic infiltrate. Image (4) Low power: lymphatics are markedly distended by massive histocytic infiltrate. Image (5) Medium power: lymphatics are markedly distended by massive histocytic infiltrate. Image (6) Medium power: lymphatics are markedly distended by massive histocytic infiltrate. Image (7) High power: large histiocytes with vesicular nuclei, prominent nucleoli and abundant clear cytoplasm that contains many intact PMNs, lymphocytes and plasma cells (emperiopolesis) Image (8) High power: large histiocytes with vesicular nuclei, prominent nucleoli and abundant clear cytoplasm that contains many intact PMNs, lymphocytes and plasma cells (emperiopolesis) Image (9) High power: large histiocytes with vesicular nuclei, prominent nucleoli and abundant clear cytoplasm that contains many intact PMNs, lymphocytes and plasma cells (emperiopolesis) Image (10) IP-CD1a stain: The histiocytes are negative for CD1a Image (11) IP-S-100 stain: The histiocytes are positive for S-100 protein Image (12) IP-S-100 stain: The histiocytes are positive for S-100 protein

Diagnosis

Rosi-Dorfman Disease (RDD), extranodal type. The histiocytes were positive for S-100 and negative for CD1a; this immunohistochemical profile is consistent with Rosi-Dorfman disease.

Langerhans cell histiocytosis is marked by a prominent eosinophilic infiltrate with little or no emperiopolesis. Langerhans cells are mononuclear (occasionally multinucleated), medium sized, and smaller than the large histiocytes in RDD; they are characterized by abundant eosiniphilic cytoplasm and large, irregular, oval to bean-shaped, pale nuclei marked by prominent grooves. Langerhans cells are positive for both S-100 and CD1a.

Nonspecific sinus histiocytosis is usually associated with local trauma or a storage disease; it can be particularly prominent in lymph nods draining cancers, such as carcinoma of the breast. Massive lymphadenopathy is rare. Microscopically, Follicular hyperplasia is frequently present; sinuses are expanded by phagocytic macrophages that are negative for both S-100 and CD1a. Emperiopolesis is inpicuous or absent; erythrophagocytosis may occur.