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INTERESTING IMAGE
Year : 2023 | Volume
: 38
| Issue : 1 | Page : 89-90
18F fluorodeoxyglucose positron emission tomography/computed tomography findings in a case of metastatic eccrine porocarcinoma – An extremely rare malignant adnexal tumor
Sarin Krishna1, Mudalsha Ravina1, Amit Kumar2, Subhajit Dasgupta1, Rutuja Kote1
1 Department of Nuclear Medicine, AII India Institute of Medical Sciences, Raipur, Chhattisgarh, India
2 Department of Medical Oncology, AII India Institute of Medical Sciences, Raipur, Chhattisgarh, India
Correspondence Address:
Dr. Mudalsha Ravina
Department of Nuclear Medicine, All India Institute of Medical Sciences, Raipur - 492 099, Chhattisgarh
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/ijnm.ijnm_140_22
Abstract
Porocarcinoma is a rare malignant neoplasm of eccrine sweat glands representing 0.005 to 0.1% of all cutaneous tumors. As eccrine porocarcinoma carries a high risk of recurrence and metastases, early diagnosis and management are crucial to lower mortality rate. We present the case of porocarcinoma in a 69-years-old woman who underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for staging the disease. PET/CT showed metabolically active multiple cutaneous lesions and also picked up lymph nodal and distant metastases to lungs and breast accurately. PET/CT is useful for accurate staging of the disease and for treatment planning.
Keywords: 18F-fluorodeoxyglucose positron emission tomography/computed tomography, acrosyringium, eccrine porocarcinoma, poroma
A 69-years-old-woman with no major past medical history came to our hospital with painful skin nodules in the left axilla of 4 months' duration. On examination, multiple erythematous and ulcerative nodules of varying sizes were noted involving the left axillary region [Figure 1]g. Punch biopsy was done from the left axillary lesion which showed dermal proliferation of atypical cells arranged in nests and cords with high mitotic activity. Histopathological diagnosis of porocarcinoma was made and the patient was referred to our department for staging positron emission tomography/computed tomography (PET/CT). After proper preparation, 210MBq of 18F-fluorodeoxyglucose (FDG) was given as intravenous bolus to the patient and scan was acquired after 45 min of injection. Maximum intensity projection image (MIP, [Figure 1]a, black arrow heads) shows multiple intense tracer avid lesions in the left breast and axillary regions. Note is also made of multiple mild-to-moderate tracer avid foci in the anterior chest wall bilaterally and in the upper abdomen [Figure 1a, black thin arrows]. Axial- and coronal-fused PET/CT images show intense tracer avid multiple cutaneous lesions [[Figure 1]b, [Figure 1]c and [Figure 1]f, white thin arrows] involving the left axillary region and left breast lesion [[Figure 1]b, white arrow head]. Axial-fused PET/CT images [Figure 1]d and [Figure 1]e show tracer avid pulmonary nodules [[Figure 1]e, white right-angled arrow], mediastinal [[Figure 1]b, white-curved arrow], and gastrohepatic lymph nodes [[Figure 1]d, white curved arrow]. 18F-FDG PET/CT findings were consistent with eccrine porocarcinoma involving the left axillary region with mediastinal, gastrohepatic lymph nodal, pulmonary, and left breast metastases. Porocarcinoma is a rare malignant appendageal tumor representing 0.005 to 0.1% of all cutaneous tumors.[1] It arises from the terminal cells of intraepithelial part of eccrine cells called as acrosyringium.[2] The exact etiology is not known but is believed to either arise de novo or by malignant transformation of long-standing poroma. It occurs mainly in the age group of 60–80 years with no gender difference. Clinically, it presents as erythematous and violaceous nodules with or without ulceration and is often misdiagnosed as squamous cell carcinoma.[3] The final diagnosis is based on histopathology findings which commonly include nuclear atypia, an infiltrative growth pattern, increased mitosis, and necrosis.[4] Immunohistochemistry is often positive for Cytokeratin (CK), keratin, carcinoembryonic antigen, epithelial membrane antigen, p53 and p63.[4] Around 20% cases of eccrine porocarcinoma metastasize to regional lymph nodes with a mortality rate of 67%.[5] The local recurrence rate is 20% in case of lymph nodal involvement. Distant metastases are seen in only 10% of cases and the sites involved include lung, retroperitoneum, bone, liver, breast, bladder, peritoneum, or ovary.[6] As of now, there are no standard guidelines for the workup and management of porocarcinoma. In this case report, staging PET/CT showed high metabolism in both primary and secondary lesions of porocarcinoma. PET/CT accurately picked up local and distant metastases, hence could be used for staging, recurrence assessment, and follow-up of eccrine porocarcinoma.
Figure 1: (a) Maximum intensity image (a: black arrow heads) shows multiple intense tracer avid lesions in the left breast and axillary regions with multiple tracer avid foci in the anterior chest region bilaterally and upper abdomen (a: black thin arrows). (b) Axial- and coronal-fused PET/CT images show intense tracer avid multiple cutaneous lesions (b: white thin arrows) involving the left axillary region, left breast lesion (b: white arrow head), and mediastinal lymph nodes (white curved arrow). (c and f) Axial- and coronal-fused PET/CT images show intense tracer avid multiple cutaneous lesions (c and f: White thin arrows) involving the left axillary region. (d and e) Axial-fused PET/CT images show tracer avid pulmonary nodules (e: white right-angled arrow), gastrohepatic lymph nodes (d: white-curved arrow). (g) multiple erythematous and ulcerative nodules of varying sizes involving the left axillary region. PET/CT: Positron emission tomography/computed tomographyDeclaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed
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