PMC8349057_01
a-d: Photos of the external presenting appearance of skin abnormalities on the left forearm and hand: Fig. 1a and b: the left forearm with mild swelling (non-pitted, non-indurated, no erythema); 1b (close view). Fig. 1c and d: there are some subtle irregular papules on the dorsum of the left hand without discoloration (1d), without digital nail pitting or clubbing (1c).
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At follow-up in clinic a week later the patient's forearm had progressed to multiple lesions that were firm, non-tender, and palpable in the subcutaneous tissue with no outward appearance on the skin or digital clubbing or pitting of the nails (Fig. 1a, b, 1c, 1d).
a, b, c: (a) Axial T1-weighted MRI image demonstrates diffuse low signal non mass like infiltration of the subcutaneous tissues of the posterior elbow (arrow).. (b) Axial fat saturated T2 image shows areas of increased reticular signal within the posterior elbow subcutaneous tissues (arrow).. (c) Axial contrast enhanced fat-saturated T1-weighted MRI image demonstrates diffuse non mass like enhancement of the subcutaneous tissues of the posterior elbow (arrow).
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No focal mass or abnormal fluid collection was visualized. (Fig. 2a, b, 2c).
a, b, c: (a) Multinucleated giant cell containing an asteroid body, which may be seen in granulomas of any etiology (H&E, original magnification 600x).. (b) Higher power view showing multinucleated giant cells within a granuloma. (H&E, original magnification 100x).. (c) Low power view of the skin biopsy showing that the dermis is heavily infiltrated by round non-necrotizing granulomas (H&E, original magnification 12.5x).
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An open surgical biopsy was performed by orthopedics and a skin biopsy was performed by dermatology (Fig. 3a, b, 3c).
a, b, c, d: CT images obtained in 2011, 2015, and 2019.. (a) Axial CT image in December 2011 with patchy centrilobular ground-glass attenuation and tree-in-bud nodularity involving the right upper lobe.. (b) Axial CT image in October 2015 with only minimal scattered centrilobular ground-glass attenuation and nodularity involving both upper lobes.. (c, d) Axial and Coronal CT images in January 2019 show small mediastinal and paratracheal lymph nodes (arrows) which are not pathologic based on size criteria (all less than 10 mm in short axis diameter) and unchanged from prior exams.
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Although a CT scan done in January 2019 did not show adenopathy (Fig. 4a-d), a repeat scan in July 2019 (several weeks after the presentation discussed in this article), demonstrated new bulky bilateral hilar and mediastinal lymphadenopathy (Fig. 5a-d).
a, b, c, d, e, f, g: CT images obtained in July 2019.. (a, b): Axial and Coronal CT images show numerous enlarged mediastinal and paratracheal lymph nodes (arrows).. (c, d): Axial and Coronal CT images with lung window settings show normal lung parenchyma.. (e,f, g): Corresponding PET-CT images with increased metabolic activity of the mediastinal and paratracheal lymph nodes.
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August 2019 confirmed the presence of hypermetabolic mediastinal and left axillary lymphadenopathy, accompanied by hypermetabolic activity along the left forearm in the area where non-caseating granulomas had been biopsied (Fig. 5e,f,g). Angiotensin converting enzyme (ACE) testing at that time was unremarkable (two prior tests, < 20 U/L, normal 14-82 U/L).