Solitary mastocytoma in an adult with an unusual clinical presentation

Abstract

To the Editor: A 30-year-old woman presented with a 10-year history of headaches, flushing, and anaphylaxis triggered by exercise, stress, heat, or scalp friction. Recently, she noticed a poorly circumscribed scalp mass. Computed tomography imaging confirmed a 3.3- × 1.5-cm subcutaneous mass, without bone involvement. The mass fluctuated in size (up to 10 cm), and episodes of anaphylaxis occurred with manipulation. Interestingly, the patient experienced no flushing or anaphylaxis while pregnant, but her symptoms returned after delivery. A punch biopsy specimen of the skin obtained from the edge of the tumor showed subtle histopathologic changes with a mild perivascular, perifollicular lymphocytic infiltrate and scattered mast cells (Fig 1). Surgical resection was performed and revealed a scalp mass with lobulated appearance. Histopathologically the tumor was composed of a dense monomorphous population of mast cells, with abundant granular cytoplasm; positive Giemsa and tryptase stains confirmed the diagnosis of mastocytoma (Fig 2). Postoperatively, the patient made a complete recovery and had no further symptoms at 27 months’ follow-up.Fig 2A and B, Intraoperative photographs of the solitary mastocytoma in vivo and after surgical resection. C and D, Hematoxylin-eosin sections showing dense population of mast cells with round nuclei, bland chromatin, and abundant granular cytoplasm. D (insert), There is diffuse immunoreactivity to mast cell tryptase.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Solitary mastocytoma is primarily a disease of young children, with adult cases rarely reported.1Pandhi D. Singal A. Aggarwal S. Adult onset, hypopigmented solitary mastocytoma: report of two cases.Indian J Dermatol Venereol Leprol. 2008; 74: 41-43Crossref PubMed Scopus (2) Google Scholar Lesions are typically cutaneous, involving the extremities, face, scalp, and trunk. Cutaneous mastocytomas may be associated with systemic disease, but up to 15% of patients with a mast cell disorder may develop a solitary mastocytoma without systemic involvement.2Castells M.C. Extracutaneous mastocytoma.J Allergy Clin Immunol. 2006; 117: 1513-1515Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar In our case, a diagnosis of concurrent systemic mastocytosis was suspected, but not confirmed. The bone marrow biopsy specimen showed few clusters of mast cells (>15 cells). The serum tryptase level ranged from 11 to 14 ng/mL; therefore, under the World Health Organization (WHO) threshold of 20 ng/mL. Thus, by WHO criteria, one major criterion was met (clusters of >15 mast cells), but no minor criteria were satisfied for the diagnosis of systemic mastocytosis.3Valent P. Horny H.P. Li C.Y. Longley J.B. Metcalfe D.D. Parwaresch R.M. et al.Mastocytosis.in: Jaffe E.S. Harris N.L. Stein H. Vardiman J.W. World Health Organization Classification of Tumors: Tumours of the Haematopoietic and Lymphoid Tissues. IARC Press, Lyon, France2001: 291-300Google Scholar Molecular studies showed no D816V mutation in the KIT gene and no evidence of the FEP1L1-PDGFRA fusion transcript. Adult-onset mastocytoma has a less favorable rate of spontaneous resolution compared with the childhood lesions, and surgical excision may be necessary.1Pandhi D. Singal A. Aggarwal S. Adult onset, hypopigmented solitary mastocytoma: report of two cases.Indian J Dermatol Venereol Leprol. 2008; 74: 41-43Crossref PubMed Scopus (2) Google Scholar Preoperative collaboration with the anesthesiology team is important to avoid hemodynamic instability during surgical manipulation. Our patient was premedicated with oral cetirizine. It is noteworthy that in this case the tumor became evident only years after the onset of nonspecific clinical symptoms. The initial histopathologic changes were very subtle, offering only a hint of what would later be seen in the surgical specimen. This fact may be explained by the superficial nature of the biopsy and illustrates the necessity of close follow-up and clinical-pathologic correlation when similar findings are encountered on the biopsy specimen. Interestingly, the patient had a complete lack of symptoms during pregnancy, with symptoms returning postpartum. To our knowledge, this is the first report of concurrent solitary mastocytoma and pregnancy, with complete control of mastocytoma-related symptoms during pregnancy. It has been previously reported that pregnancy may worsen the symptoms of mastocytosis.4Donahue J.G. Lupton J.B. Golichowski A.M. Cutaneous mastocytosis complicating pregnancy.Obstet Gynecol. 1995; 85: 813-815Crossref PubMed Scopus (19) Google Scholar, 5Worobec A.S. Akin C. Scott L.M. Metcalfe D.D. Mastocytosis complicating pregnancy.Obstet Gynecol. 2000; 95: 391-395Crossref PubMed Scopus (37) Google Scholar