results suggest a role for p21 and cyclin D1 in the progression of vulvar squamous cell carcinoma. S Knopp R Holm T Bjørge C Trope ´ J M Nesland The National Hospital, The Norwegian Radium Hospital, University of Oslo, Oslo, Norway 1. Knopp S, Bjorge T, Nesland JM, Trope C, Scheistroen M, Holm R. p16INK4a and p21Waf1 ⁄ Cip1 expression correlates with clinical outcome in vulvar carcinomas. Gynecol. Oncol. 2004; 95; 37–45. 2. Knopp S, Bjorge T, Nesland JM, Trope C, Holm R. Cyclins D1, D3, E, and A in vulvar carcinoma patients. Gynecol. Oncol. 2005; 97; 733–739. 3. McKay JA, Douglas JJ, Ross VG et al. Expression of cell cycle control proteins in primary colorectal tumors does not always predict expression in lymph node metastases. Clin. Cancer Res. 2000; 6; 1113–1118. 4. Sherr CJ, Roberts JM CDK inhibitors: positive and negative regula- tors of G1-phase progression. Genes Dev. 1999; 13; 1501–1512. 5. Pinto AP, Schlecht NF, Pintos J et al. Prognostic significance of lymph node variables and human papillomavirus DNA in invasive vulvar carcinoma. Gynecol. Oncol. 2004; 92; 856–865. 6. Funk JO, Waga S, Harry JB, Espling E, Stillman B, Galloway DA. Inhibition of CDK activity and PCNA-dependent DNA replication by p21 is blocked by interaction with the HPV-16 E7 oncoprotein. Genes Dev. 1997; 11; 2090–2100. Meningioma-like endometrial stromal nodule with a stromal-derived foam cell component DOI: 10.1111/j.1365-2559.2006.02439.x Sir: Endometrial stromal neoplasms can exhibit wide morphological variation. 1,2 Among them, endometrial stromal nodules (ESN) are typically small, benign tumours, 3 which grow in a nodular expansile fashion and are composed of a diffuse proliferation of endo- metrial stromal cells with a characteristic vascular pattern. We present a case of a large ESN with an exclusive plexiform histology featuring a predominant whorled pattern unrelated to blood vessels and numerous foam cells with an endometrial stromal phenotype. Its appearance was remarkably similar to meningothelial meningioma. The tumour was found at ultrasound examination of a 55-year-old multiparous patient who presented with abdominal pain. She was morbidly obese and her periods had not ceased. She underwent excision of the tumour followed by total abdominal hysterectomy and bilateral salpingo-oophorectomy. Grossly, the 170-mm diameter intramyometrial tumour was soft and showed extensive yellow areas (Figure 1). It was well circumscribed and showed a pushing margin. Histology revealed a uniform pattern of whorled, target-like cellular nests unrelated to blood vessels (Figure 2a). Centrally, cells had bland oval nuclei, but in the outer aspects of the nests they appeared elongated and merged with the intervening fibroblastic stroma. Vessels were of sinusoidal type, but thick-walled arterioles were also present. Foam cells (Figure 2b) comprised over 50% of the tumour and were arranged in sheets within the intervening stroma, clustering around capillary-sized sinusoidal vessels. Neither hyaline plaques nor sex-cord elements were seen. Mitotic figures were rare. Immunohistochemically, the whorled nests stained strongly positive for CD10 (Figure 2c), progesterone receptors (Figure 2d), aromatase (Figure 2e) and a-actin. The cytoplasm of two-thirds of the foam cells stained strongly positive for CD68. However, the remaining third was CD68–, but had membran- ous staining for aromatase (Figure 2f) and CD10 (Figure 2g), as well as strong nuclear staining for progesterone receptors (Figure 2h). Both tumour and foam cells were negative for a-inhibin, cytokeratins, Figure 2. Tumour is arranged in numerous syncytial whorls (a) coexisting with foam cells, (b) with supporting vasculature by numerous small vessels. Immunohistochemically, concentric whorls are positive for CD10 (c), progesterone receptors (d) and aromatase (e). Foam cells exhibit analogous but focal positivity for aromatase (f), CD10 (g) and progesterone receptor (h). Sinusoidal capillaries are present (h). Ó 2006 The Authors. Journal compilation Ó 2006 Blackwell Publishing Ltd, Histopathology, 49, 309–328. Figure 1. Gross appearance of well-circumscribed intramyometrial tumour with yellow areas. 312 Correspondence