LAUSR

References 1 Luz FB, Rochael MC, Ramos-eSilva M. Reticulohistiocytoses: a unique spectrum of non-LANGERHANS cell histiocytosis. Skinmed 2018; 16: 167–176. 2 Zak FG. Reticulohistiocytoma (‘ganglioneuroma’) of the skin. Br J Dermatol 2019; 62: 351–355. 3 Miettinen M, Fetsch JF. Reticulohistiocytoma (Solitary epithelioid histiocytoma): a clinicopathologic and immunohistochemical study of 44 cases. Am J Surg Pathol 2006; 34: 521–528. 4 Zinn DJ, Chakraborty R, Allen CE. Langerhans cell histiocytosis: emerging insights and clinical implications. Oncology (Williston Park) 2016; 30: 122–132. 5 Bonometti A, Berti E, for Associazione Italiana Ricerca Istiocitosi ONLUS. Reticulohistiocytoses: a revision of the full spectrum. J Eur Dermatol Venereol 2020; 34: 1684–1694. Primary cutaneous alveolar rhabdomyosarcoma: Report of a case and literature review Dear Editor, Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents. It represents 5–8% of all solid tumors in the pediatric population. Up to 85% of RMS occurs in patients younger than 20 years, but cases in adults are unusual. RMS is classified into three major histologic subtypes: embryonal RMS (eRMS), alveolar RMS (aRMS), and pleomorphic RMS. Direct skin invasion from soft tissues is common, but primary cutaneous RMS is very rare. aRMS with a primary presentation in the skin accounts for <0.7%. A previously healthy 18-year-old male presented with a 1year history of a nodule on the back of the left hand with progressive growth (Fig. 1). He had pain in the entire limb, and edema and hypoesthesia were also present with a sudden increase in size. Months later, he developed a tumor in the left axillary fossa with ulceration, secretion of serosanguineous material, and movement restriction. One month before admission, the patient presented malaise, hyporexia, weight loss of 3 kg, and fever. A previous computed tomography (CT) scan showed a subcarinal necrotic mediastinal adenopathy measuring 4 9 2.6 cm and another adenopathy at the level of the left hilum measuring 3.2 9 2.5 cm. Three days before admission, he presented sudden quadriparesis. A skin biopsy was performed along with Gram and acid-fast bacilli staining, KOH, and bacterial and mycotic cultures. CT imaging demonstrated multiple necrotic ganglionic conglomerates of 15 cm at the base of the neck in addition to axillary 14 9 10 9 9.8 cm, left cervical 4.5 9 3.6 cm, left subcarinal 3.5 9 3.1 cm, and hilum mediastinal 2.6 9 1.9 cm adenopathies. Figure 2 Histopathologic examinations. (a) Well-demarcated nodule located in the dermis (Hematoxylin and Eosin, 409). (b) Predominantly infiltrated cells are large histiocytes with ample eosinophilic cytoplasm. Amount of eosinophils and lymphocytes are present (Hematoxylin and Eosin, 2009). On immunohistochemical staining, infiltrated cells were positive for (c) CD68 and negative for (d) CD1a and (e) S-100 protein (original magnification 2009)